Class 
 Book 
 
 :Sa^ 
 
 i 'U 
 
 Gop^htN^ 
 
 COPYRIGHT DEPOSIT. 
 
American 
 
 Pattern Shop 
 
 Practice 
 
 By 
 
 H. J. McCaslin 
 
 First Edition 
 1907 
 
 Cleveland, Ohio 
 

 LIBRARY of CONGRESS 
 Two Cooles RecelTed 
 MAY 6 190^ 
 
 CLASS A XXc 
 
 /'l 2^ 
 
 COPY B 
 
 '1' 
 C, No. 
 
 COPYRIGHTED 
 BY 
 
 THE FRONTIER COMPANY 
 1907 
 
 THH CLEVBLAND PRINTING COMPANY 
 CI EVELAND. OHIO 
 
 n^i ^DQ^ 
 
PUBLISHERS' NOTE 
 
 The sections of this volume have been arranged as separate parts, 
 each paged separately, the object in this being to enable the publishers 
 to make revisions in future editions without having to destroy a large 
 number of plates, as it is the belief of The Frontier Company that 
 any book should be kept up to date by frequent revision. 
 
 In order to make the index applicable to a book of this style, it 
 has been necessary to combine with the page numbers a series of 
 Roman numerals indicating the sections ; for instance, if one desires 
 to look in the index for the Involute Odontograph Table, they will find 
 a reference to 7-IV. This means that you must run through the book 
 until the IV is found in conjunction with the page numbers, or in other 
 words, turn to section IV and then to the 7th page. 
 
 Both the author and the publishers will be very glad indeed to 
 have anyone point out any errors or omissions in this work, or to 
 suggest any additions or corrections which would improve future 
 editions. 
 
 The Frontier Company. 
 
PREFACE 
 
 The literature pertaining to patternmaking not being as extensive 
 as the importance of the business warrants, it has occurred to the 
 writer that it would be well to offer some of the results of his own 
 experience in the form of short articles and suggestions. 
 
 Considerable writing has been done along this line and a number 
 of books published, but nevertheless the writer believes that the field is 
 large enough for one more which treats the subject in a somewhat 
 different manner, as the molding and core making as well as the pat- 
 ternmaking has been treated in each case. 
 
 Patterns, rigs and methods for producing steel castings form a 
 special feature, and the examples given are thoroughly explained as 
 is also the subject of core molding and multiple molding for steel cast- 
 ing work. 
 
 Core box work is regarded as the most intricate and important 
 part of patternmaking, and among the subjects selected as illustrations 
 will be found excellent examples of this part of the work. 
 
 While the art of patternmaking cannot be acquired alone through 
 the study of books, a general and broader knowledge can be obtained, 
 as no one individual can have the experience of manv. 
 
 The variety of designs in castings and the conditions to be met 
 make it impossible to apply any conventionary or set method to 
 patternmaking at large, each particular object determining the method 
 of molding and the construction of the pattern. In this connection 
 it is desired that the succeeding articles be accepted as suggestions 
 or examples, which have given practical results in the cases under con- 
 sideration. Many, if not the greater portion of the subjects illus- 
 trated and described in this volume have previously appeared as 
 articles in the Anicricaii MachiiAst, Patternmaker, Wood Craft and 
 the Foundry, under the writer's signature. In re-arranging the work 
 under book form, many additions, alterations and corrections have been 
 made in the original articles, and it is hoped that the volume will be 
 useful to many patternmakers. 
 
 The author wishes to acknowledge his indebtedness to many 
 friends who have furnished valuable suggestions for the work. 
 
CONTENTS 
 
 Section I 
 ENGINE PATTEKNS 
 
 PAGE 
 
 A Slide Valve Cylinder l-I 
 
 Pattern for a Low Pressure Cylinder 7-1 
 
 A Piston Valve Cylinder Pattern 16-1 
 
 Pattern for a Double Piston Valve Cylinder 30-1 
 
 Patterns for a Heavy Engine Bed 39-1 
 
 Section II 
 
 MOLDING AND CORES 
 
 Multiple Core Molding l-II 
 
 Stacking Cores for Large Work 7-1 1 
 
 Casting Round Flasks in Cores 11-11 
 
 ]\Iolding a Three-way Cock 14-11 
 
 The Use of Covering Cores 17-11 
 
 T Slot and Name Plate Cores 20-11 
 
 IMolding in Cores 23-11 
 
 The Use of Nail Cores 34-11 
 
 Section III 
 SWEEP WORK 
 
 Sw^eeping a Plain Cylinder l-III 
 
 Sweeping the Mold for a Suction Chamber 7-III 
 
 Sweeping Cast Steel Slag Ladle Molds 12-III 
 
 A Furnace Hopper and Bell 17-III 
 
 Sweeping a Cylindrical and Conical Drum 24-ni 
 
 Sweeping Rigs 36-in 
 
 Section IV 
 GEARING 
 
 Spur Gearing 1-IV 
 
 Bevel and Worm Gear Patterns 18-1 V 
 
CONTENTS 
 
 Section V 
 REPRESENTATIVE PATTERNS 
 
 PAGE 
 
 Pattern for a Throttle Valve Body 1-V 
 
 Pattern for a Pinion Housing 8-V 
 
 Hawser Pipe Patterns 14-V 
 
 A Nozzle Pattern 20-V 
 
 Molding Cast Steel Truck Bolsters 23-V 
 
 Rig for Producing Cylindrical Castings 3 1-V 
 
 Skeleton Patterns 39-V 
 
 Pattern for a Chilian Mill Mortar 47-V 
 
 Making a Crooked Elbow 56-V 
 
 Section VI 
 
 HINTS, SUGGESTIONS AND RIGS 
 
 Cutting the Score in a Chain Drum Pattern 1-VI 
 
 A Core Box and Clamp Combined 6-\ I 
 
 Some Lath Tools 7-VI 
 
 Wooden Ball Turning 9-VI 
 
 Shrinkage 10-VI 
 
 The Box Square 12-VI 
 
 A Core Box Plane 13-VI 
 
 Wooden Calipers 14-VI 
 
 Elbow Core Boxes 1 5- VI 
 
 Screws and End Grain 16- VI 
 
 Warping of Castings 18- VI 
 
 Arcs of Circles 21-VI 
 
 Chords of Angles 24-VI 
 
 Right Angled Triangles 26-VI 
 
 A Table of Polygons 27-VI 
 
 General Suggestions 29-VI 
 
 Striking an Ellipse 41-VI 
 
 Sawing Lags 44-\T 
 
SECTION 1 
 
 ENGINE PATTERNS 
 
 CHAPTER I 
 A SLIDE VALVE CYLINDER 
 
 Slide valve cylinders are made in a great variety of ways. I have 
 chosen and illustrated a well known type with one head and a guide 
 barrel cast with the cylinders, the guide portion being what is known 
 as a bored guide. A plan of the cylinder is shown in Fig. 1, the plan 
 being taken in such a position as to show the interior of the steam 
 chest. At the right and left of the central figure there are two end 
 views. In Fig. 2 the longitudinal section as taken on the line A A, 
 Fig. 1, is shown in the center and at the right and left cross sections 
 as taken on the lines B B and C C. These views show the arrange- 
 ment of the steam ports, exhaust chambers, oblong openings in the 
 guide barrel, etc. 
 
 In beginning operations in making the pattern for this it is first 
 necessar}' to make a full sized layout of the work, together with the 
 necessary cross sections. The mode of molding which decides the 
 parting of the patterns must next be determined. In this case the 
 pattern has been parted longitudinally through the cylinder and steam 
 chest. Along the line A A, Fig. 1, this manner of molding places the 
 slide valve seat in the vertical plane which facilitates the setting of 
 the cores. 
 
 The construction of cylinder patterns of this class depends largely 
 upon the size of the cylinder being made. If the diameter is to be 
 less than 12 inches the body of the cylinder may be glued up practi- 
 cally solid, but if the diameter is greater than 12 inches it is usuallv 
 best to stave the body up, as shown in Fig. 3. The body having been 
 roughed to form with the depressions to receive the flanges M N, 
 Fig. 4, it is removed from the lathe and the flanges fitted in place. 
 These flanges are first built up of segments, the inside sawed out, fitted 
 in place and secured. The work is then returned to the lathe and the 
 flanges and body turned to its proper dimensions, as shown in Fig. 4. 
 
2-1 
 
 ENGINE PATTERNS 
 
 The body is next taken apart and one-half carefully placed upon 
 the layout and temporarily secured there. The blocks and pieces 
 forming the various core prints and other projections are then fitted 
 in place, as shown by the two views and section of the completed pat- 
 tern. Fig. 5. The layout of the work gives the proper location for 
 the dififerent parts as they are assembled. 
 
 A box or block forming a half of the body of the steam chest, O, 
 is gotten out and fitted in place with a core print P attached. The 
 flange Q with stud bosses and stuffing box R with its core prints 
 attached are secured in place. The steam intake core print S with its 
 facing is prepared and attached, as are also the drain cock bosses T T. 
 
A SLIDE VALVE CYLINDER 
 
 3-1 
 
 The core prints U and V, for forming the oblong openings in the 
 guide, are made, fitted on and secured. It will be noticed that the 
 core print U extends each way beyond the openings and forms the 
 core print W for the feet. 
 
 The half pattern is next taken from the layout and turned over. 
 
 the other half of the body placed on it and the fitting of the parts for 
 this half proceeded with, the finished half serving as a guide. When 
 completed the pattern is fitted with leather fillets and finished. 
 
 Two views and a section of the steam chest core boxes are shown 
 in Fig. 6. This illustrates the general construction and arrangement 
 
4r-I 
 
 ENGINE PATTERNS 
 
 of the parts. The loose pieces J in each end of the box form the 
 stuffing and steam intake portions of the core. When the core has been 
 rammed up in the box these loose pieces are withdrawn and the space 
 occupied by them filled in with sand, so as to support the projecting 
 parts of the core when the box is rolled over and also during the 
 drying of the core. 
 
 For receiving the ends of the steam ports and exhaust chamber 
 
 G 
 
 I —-Tm 
 
 Fig. o. Steam Chest Core Box. Figr- 7- Steam Port Core Box. Fig. 8. Exhaust Chamber Core 
 Box. Fig. y. .Assembled Cores 
 
 cores one large print K is made of such a size that it will receive the 
 ends of all three cores. This is better practice than the old method 
 of using three separate prints, as it simplifies the setting of the cores 
 and insures accurate measurement without greatly increasing the work 
 of making the port cores. It is necessary to provide a projecting lip 
 on the steam port cores to close the intervening space at L, Figs. 7 
 and 9. This lip also gives a greater bearing surface to the core. 
 
A SLIDE VALVE CYLINDER 
 
 5-1 
 
 A section and end view of the steam port core box are shown in 
 Fig. 7. It will be observed that a lip M M is allowed around the port 
 and exhaust core openings, as shown in Figs. 7 and 9. This provides 
 metal in the ports, so that the ports may be chipped to the correct 
 dimensions, so as to give exactly the desired area and perfect cut-off. 
 
 A core box for half of the exhaust chamber core is shown in 
 Fig. 8. It is necessary to make two of these, one right hand, the 
 other left hand. The core can be entire, or in halves and then fastened 
 together. If it is made in halves it can be dried on a flat plate, which 
 has some advantages. 
 
 A longitudinal section of the assembled steam chest, steam port 
 and exhaust chamber cores is shown in Fig. 9. This illustrates the 
 manner in which the cores are secured together. The openings N N 
 
 SECTION I 
 
 Fig. 10. Core Box for Bore of Cylinder and Guide Barrel 
 
 are provided in the bore core to allow the steam port cores to pass 
 down into the bore core, thus holding them in position in the mold. 
 These openings are made by the blocks N N in the core box, shown 
 in Fig. 10. 
 
 A plan and cross section of the core box for the core lor the bore 
 of the cylinder and also for the guide barrel are shown in Fig. 10. 
 The body of this box is staved up in the usual manner and planed out 
 to size. The material for forming the oblong openings O O is gotten 
 out and fitted to the sides of the box and secured in place. The sides 
 of the box are then cut out to conform to the pieces attached. The 
 beading P P is fitted around the opening and worked into proper 
 shape, being secured in place with loose dowels. The side of the box 
 at Q O must be made with loose pieces. In making the core the first 
 section of the loose beading P P on the side of the box is drawn before 
 
6-1 ENGINE PATTERNS 
 
 the box is rolled over. This allows the loose pieces Q Q to be drav n 
 back. 
 
 The manner of assembling the cores being shown in Fig. 9, it 
 is unnecessary to show an illustration of the entire mold, as any molder 
 would have no trouble or difficulty in coring up a mold made from 
 the pattern. In Fig. 9 the manner of taking off the vent from the 
 port cores is also indicated. 
 
LOW PRESSURE CYLINDER PATTERN 
 y CHAPTER II 
 
 PATTERN FOR A LOW PRESSURE CYLINDER 
 
 7-1 
 
 Several views of a low pressure cylinder for a marine engine 
 fitted with a slide valve are shown in Figs. 11, 12 and 13. Fig. 11 
 shows a half section and half plan. Fig. 12 shows a section on the 
 
 FiK- n. Half Plan and Half Section of Low Pressure 
 Cylinder 
 
 Fig. 12. N'ertical Section of Low Pressure Cylinder 
 
 Fig. 1.^. Projection of Steam Chest Side of Low Pres- 
 sure Cylinder 
 
 line A B C of Fig. 11, while Fig. 13 shows an elevation of the steam 
 chest face of the cylinder. This type of cylinder is quite commonly 
 used in compound marine engines. 
 
8-1 
 
 ENGINE PATTERNS 
 
 There are two ways in which the cyhnder may be molded, that is, 
 the feet may be up or they may be down. A difference of opinion 
 exists among foundrymen as to which is the more practical. Some 
 claim that better results can be obtained by molding with the feet 
 down on account of the fact that a large riser can be swept up around 
 
 , Nb31iVd iHVd 
 
 Fig. 14. Plan of Pattern Ready for Molding 
 Fig. 15. Steam Chest Face of Pattern 
 
 Fig. 16. Side of Pattern with Spindle and Sweep 
 in Place 
 
 the top of the cylinder to receive any impurities in the metal, and that 
 this will insure a better and sounder barrel for the cylinder. On the 
 other hand, the objection is raised to this method, that it is very diffi- 
 cult to secure or hold down the barrel core on account of the fact that 
 
LOJV PRESSURE CYLINDER PATTERN 
 
 9-1 
 
 if the feet are clown the core must rest upon chaplets and has a con- 
 siderable tendency to rise, thus necessitating special rigging" for bolting 
 it down. 
 
 Figr. 17. Steam Chest Core Box 
 
 Fig. 18, Core Box for Exhaust Chamber Core 
 
 Fig. 19. Box for making Port Cores 
 
 Fig. 20. Core Box for Foot Fig. 21. Core Box for Exhaust Opening 
 
 As most foundries make these cylinders in loam with their feet 
 up when large enough to be swept, that method will be described first. 
 
 Molding with the Feet Up 
 
 In beginning this work it is customary to lay out a full sized plan 
 and a vertical section through the barrel and steam chest, the allow- 
 
lO-I 
 
 ENGINE PATTERNS 
 
 ance for contraction varying from 1-16 inch to 1-12 inch per foot, 
 depending upon the size of the cyUnder. The details of the pattern 
 and sweeps are shown in Figs. 14, 15 and 16. l'\g. 14 shows a plan 
 of the pattern in place. Fig. 15 a view of the steam chest face of the 
 pattern, and Fig. 16 a view of the side of the pattern with the spindle 
 and sweep in place. The view shown in Fig. 16 is a section taken on 
 the line A B C, Fig. 14. 
 
 The conical head with its flange is built up in segments and turned 
 to the proper form. The upper portion of the steam chest is then 
 built on to the side of the conical head, as shown in Fig. 16. The 
 up])er portion of the steam chest, together with the conical head, is 
 separate from the lower portion of the steam chest with a parting as 
 shown. 
 
 Fig. 22. Rig for Sweepinsr Barrel Core 
 
 The stuffing box is turned up with a loose flange which is cut 
 into sections and held with loose pins so that these sections can be 
 drawn in. The ribs are usually attached to the stuffing box, forming 
 a loose spider which is doweled in place upon the pattern for the 
 conical head. 
 
 The patterns for the feet are made in two sections and doweled 
 together, the parting being in line with the top face of the cylinder 
 flange. The central portion of the foot is drawn first and the pro- 
 jecting portions or flanges drawn in. The portion of the foot pattern 
 
LOW PRESSURE CYLINDER PATTERN 
 
 ll-I 
 
 which forms the rib or connection with the barrel of the cyhnder is 
 secured to the pattern for the head by means of pins and screws and, 
 after the sweeping of the barrel has been completed, these are removed 
 and this portion of the foot pattern drawn into the barrel. 
 
 The face of the steam chest pattern is built to conform to the 
 diameter of the barrel, 3-16 to ^-inch clearance being allowed for the 
 sweep to pass. 
 
 The interior of this pattern is so constructed and secured together 
 with pins and screws that the middle section of each end can be 
 removed from the inside, after which the pattern collapses, and allows 
 all parts to be drawn in and removed separately. 
 
12-1 
 
 ENGINE PATTERNS 
 
 The core print for the steam chest is made as an open frame and 
 secured to the chest with cleats, as shown in Fig. 16, braces beino- 
 used across the face of the core print to keep it square. 
 
 The core box used for making one-half of the steam chest core A, 
 Fig. 23, is shown in Fig. 17. The prints for securing the steam and 
 exhaust cores B and C are shown in place. 
 
 The core box for making one-half of the exhaust chamber core 
 is shown in Fig. 18. The top of this core being struck off. 
 
 The port core box in which the two port cores are made, is shown 
 
LOW PRESSURE CYLINDER PATTERN 
 
 13-1 
 
 in Fig. 19. The top of this core is also struck off. The core boxes 
 for the foot and for the exhaust connection are shown in Figs. 20 
 and 21. 
 
 The rig for sweeping the barrel core is shown in Fig. 22. A 
 cast iron base plate A is first placed in position, a few courses of 
 brick work built upon it and loam swept on to the outside of them 
 by means of the sweep B, which during this operation is supported 
 
 Fig. 35. First Operation in Sweeping Barrel Core 
 Fig. 26. Second Operation in Sweeping Barrel Core 
 
 by the upper sweep C and the temporary arm shown by dotted lines 
 at E. The temporary arm E is then removed, the brick work built up 
 and the plate F placed in position, after which loam is swept on by 
 means of the sweep B which is carried by the sweep C and guided at 
 the bottom by the loam already swept into place. The building and 
 sweeping is continued until the entire outer surface has been finished, 
 when the sweep B can be removed and the upper portion of the work 
 finished with the aid of the sweep C, the stuffing box core being swept 
 up at the same time that the portion of the mold on top of the plate F 
 
14-1 ENGINE PATTERNS 
 
 is swept lip. When the stuffing box core is too small to be swept up 
 in this way, a separate core is made and the print swept out to 
 receive it. 
 
 The low pressure cylinder described above is a good example 
 of casting in loam. This method of casting is one used for producing 
 intricate castings of large dimensions, in which it is not likely that 
 the pieces will have to be duplicated many times. Frequently a large 
 amount of work is required in designing the rigs and sweeps for 
 loam castings, but on the other hand, the ])atterns themselves are 
 usually inexpensive, consisting as they do of sweeps and forms. 
 
 A section of the com]:)leted mold is shown in Fig. 23, showing 
 the manner in which the different cores and ])arts are assembled. In 
 beginning the mold, the cast iron foundation plate G, which is pro- 
 vided with suitable handling lugs, is first leveled up and a socket 
 provided for the spindle. The pattern is then placed above the plate 
 and blocked in position. The overhanging ])ortion which contains 
 the cope surface of the head is supported with temporary braces placed 
 outside of where the bricking up is to be done. The space below 
 the steam chest is then filled in with brick and a thickness of loam 
 placed against the pattern. A seat or print H is swept up to receive 
 the barrel core and a built up parting made around the outer edge, 
 upon which the cast iron lifting plate I is placed to carry the middle 
 section of the mold. This section is also built up of brick and loam. 
 The sweep shown in Fig. 16 forms the outer diameter of the barrel. 
 
 The steam chest face of the mold is left open, the brick work 
 butting against the core print on each side, and the opening being 
 closed later when the cores are in position. 
 
 The top or cope part is formed by placing an ordinary flask on 
 top of the brick work and ramming up a dry sand cope, care being 
 taken to provide the necessary bars and skeletons for lifting out the 
 deep pockets. 
 
 The cope is lifted off, the pattern drawn, and the sections of the 
 mold and barrel core placed in the core oven and dried. 
 
 A pit is prepared and the foundation plate, or lower part of the 
 mold, lowered into it and leveled up properly. The middle section is 
 next placed in position, the offset parting guiding it into the proper 
 relationship to the base. The core for forming the opening on the 
 lower side of the steam chest is next set, the cores B and C having 
 been secured to the cores A before they are placed in position. The 
 upper cores are then secured together and placed in position. The 
 cores for forming the intake and exhaust connections on the steam 
 chest are usually inserted from the outside through openings left in 
 
LOIV PRESSURE CYLINDER PATTERN 15-1 
 
 the brick work. The barrel core is next carefully lowered into position 
 and chaplets are then placed on top of the barrel core and the cope 
 placed on. 
 
 The space between the walls of the pit and the mold is filled 
 up by ramming in sand and provision made for the necessary gates. 
 The mold is then weighted down, after which it is ready for pouring. 
 
 Molding with the Feet Down 
 
 The manner in which the pattern is fitted up for molding when 
 the feet are to be cast down is shown in Fig. 24. The barrel is formed 
 by a sweep in both instances. A ring is built up and turned, containing 
 the lower flange of the cylinder, to which the feet and the ribs support- 
 ing the stuffing box are secured. The upper part of the sweep is so 
 arranged as to form a riser around the top of the cylinder. 
 
 When this method is employed, the sweeping of the barrel core 
 is somewhat more intricate, and it is shown in Figs. 25 and 26. It 
 is first necessary to place the Prickard plate A with its face up as 
 shown in Fig. 25 and sweep on the necessary thickness of loam with 
 the sweeps B and C. The plate A is then dried and turned over, after 
 which the brick work is built up and the main body swept by means 
 of the sweep D as shown in Fig. 26. 
 
1&-I 
 
 ENGINE PATTERNS 
 
 CHAPTER III 
 
 A PISTON VALVE CYLINDER PATTERN 
 
 Piston valve cylinders, as the name implies, are cylinders in which 
 the steam is controlled by a piston or cylindrical valve, moving in a 
 barrel or chamber parallel to the bore of the cylinder. The example 
 chosen to illustrate this type is a pattern for a 32 x 36 cylinder of the 
 above mentioned design. This cylinder is for use in connection with 
 a heavy duty reversible engine. Fig. 27 shows a half plan of the 
 cylinder and a half section through the axes of the cylinder and the 
 
 Fig. 27. Half Plan and Half Section of Cylinder 
 
 steam chest, showing the plan of one port, relief valve opening, etc. 
 By examining the plan view it will be observed that the cylinder is 
 symmetrical about the center line A-A. 
 
 A half elevation of the cylinder as seen from the steam chest 
 side is shown in Fig. 28 together with a half cross section on the line 
 B-B of Fig. 27. This section shows the metal thickness, etc. A cross 
 section of the cylinder and steam chest on the center line A-A of 
 Fig. 27 is shown in Fig. 29. This section serves to show the exhaust 
 chamber, relief valve connection and bolting down lugs. The end 
 view of the cylinder is shown in I'ig. 30. 
 
PISTON VALVE CYLINDER PATTERNS 
 
 17-r 
 
 Before commencing the construction of any part of the pattern its 
 position and method of molding must be determined. Having chosen 
 a horizontal position for the pattern under discussion, it must be 
 parted through the axes of the cylinder and steam chest on the lines 
 C-C, Figs. 29 and 30. 
 
 Pattern Construction 
 
 In beginning the work a full size lay-out or a partial lay-out is 
 essential. As the cylinder and steam chest are symmetrical about the 
 center line A-A, Fig. 27, it is only necessary to draw a one-half lay-out 
 
 c- 
 
 Fig. 28. Half Elevation and Half Section of Cylinder 
 
 of the plan, with the outline of the steam ports, etc.. also a cross 
 section as shown in Fig. 29, these two lay-outs being sufficient. 
 
 The assembled and completed pattern is illustrated in plan iu 
 Fig. 31 and elevation in Fig. 2)2, being shown in a reverse position 
 to that in wiiich it is molded, this being the position the pattern 
 occupied during assembling. 
 
18-1 
 
 ENGINE PATTERNS 
 
 For convenience in referring to the separate parts of the pattern 
 during its description let us designate them as A, B C, D, etc., as 
 shown in the completed pattern Figs. 31 and 2>2. 
 
 Part A of the pattern is shown in plan and cross section in Fig. 33 
 and consists of the lower part of the base of the cylinder. This can 
 be constructed somew^hat after the manner shown. It will be observed 
 by examining Figs. 28 and 29 that one-half of the cylinder and steam 
 chest is contained in this part of the casting, being of course formed 
 by the core. 
 
 In commencing part A, three frames are gotten out, being nailed 
 and glued together in a manner similar to that employed in the con- 
 struction of segment work, that is, each frame is composed of three 
 
 Fig. 29. Section on the Line .\ A, Fig. 27 
 
 Fig 30. End View of Cylinder 
 
 thicknesses of material. The two frames which form the ends of the 
 base are covered or closed in with the proper thickness of material. 
 After this is done one frame is laid out and sawed to the proper form 
 of the base, less the thickness or lagging with which they are inclosed. 
 This frame is then used as a templet to mark ofif the other two which 
 are sawed to correspond. The three frames are then placed upon a 
 level surface, lined and squared up and secured together in a good 
 substantial manner with bars or braces. The lagging of the sides of 
 the frames is then proceeded with. 
 
 If the frames are laid ofif and sawed out accurately the lagging 
 can be gotten out to the exact thickness and in narrow^ strips. It is 
 then nailed and glued in place, when it will require but a small amount 
 of dressing with a round sole plane, followed by the usual application 
 of sandpaper. 
 
 Next the. center lines of the cylinder and steam chest and of the 
 bolting down lugs are carefully and accurately laid ofif across the 
 parting of the pattern and down the ends and sides. 
 
^- 
 
 Fi(J. 32 
 
 Fig. 31. Plan of Finished Pattern 
 Fig. 32. End Elevation of Finished Pattern 
 
*20-I 
 
 EXGIXE PATTERNS 
 
 Material is gotten out for the bolting down lugs and they are 
 worked out and sawed to conform to the sides of the base, when they 
 are fitted and secured in place. The two relief valve bosses, with 
 their core prints, are also gotten out and secured in place. 
 
 It will be found convenient in molding if these latter mentioned 
 parts are attached with screws and loose dowels inserted from the 
 interior of the pattern, as this manner of securing these loose pieces 
 permits of their withdrawal from the sand during the finishing of 
 the mold. 
 
 ff— 
 
 Fig. 33. Base Portion of Pattern 
 
 It will be observed by examining Fig. 29 that the combined 
 diameters of the cylinders and steam chest do not inclose the entire 
 parting or top of the base, so that there is a space left between these 
 two parts. For this reason the material A-Z is inserted and secured 
 between the frames as shown in Fig. 33. 
 
PISTON VALVE CYLINDER PATTERNS 
 
 21-1 
 
 The pattern is next turned over and the bottom inclosed. It 
 will be observed, however, that a portion of the material used in 
 closing in the bottom is cleated together, this being done to allow of 
 its removal to give access to the interior of the pattern for the removal 
 
 A-T 
 
 J'art B 
 
 :A-r 
 
 Fig. 35. Half Steam Chest Pattern 
 
 Fig. 34. Half Cylinder Pattern 
 
 of screws, loose dowels, etc., during molding. This loose bottom also 
 facilitates the drawing of the pattern, as it affords the molder a good 
 opportunity for rapping the inside of the pattern. 
 
 The bottom having been dressed off and sandpapered, the core 
 outline should be carefully laid out and dotted or painted in. This 
 
22 I 
 
 ENGIXE PATTERNS 
 
 is often considered unnecessary by patternmakers, but the writer be- 
 lieves the time spent in doing this is invested to good advantage, as 
 it shows the molder the metal cHstribution, which often determines 
 the point of gating. Another good reason for drawing in a core outHne 
 when no cope core print is used, as in the case under discussion, is 
 tliat the molder can see at a glance where he must make provision 
 for taking off the vent from cores which must be vented up through 
 the cope. 
 
 Fiff. 37 
 
 Figr. 36. Half Flanges and Prints Fig. 37. Half Prints and Facings 
 
 With the locating and placing of the conical core prints for the 
 bolting down lugs, this part of the pattern is practically completed. 
 
 Next one-half of the c\linder B and of the steam chest C, as 
 shown in Figs. 34 and 35, are barreled or lagged up over built up 
 frames as shown. These frames are built up and sawed out to the 
 required outside diameter less the thickness of the lagging. As previ- 
 ously stated, if the lagging is applied in narrow widths, very little 
 dressing will be required to bring it to form. 
 
 After the cylindrical part B has been worked up in this manner 
 and dressed off, the material A-Y is applied to the ends to reinforce 
 the counterbore at each end of the cvlinder. This material is dressed 
 
PISTOX VALVE CYLINDER PATTERNS 
 
 23-1 
 
 up and attached as shown. The stock can be gotten out in any con- 
 venient width and owing to its being rather thin it will conform to 
 the curve of the cylinder without any difficulty. 
 
 In length these two half barrels or half cylinders B and C are 
 equivalent to the length of the line A-X in Fig. 31, or the distance 
 between the end flanges D of the cylinder and steam chest. 
 
 Fig. 38. Steam Port Pattern 
 
 Fig. 41. Stiffeninsr Rib for Steam Chest 
 
 Fig. 39. Exhaust Cylinder Pattern 
 Fig. 40. Stiffening Rib for Cylinder 
 
 After completing these two parts and locating them on the base 
 portion A, we proceed with the part D, as shown in two views, Fig. 36. 
 This portion of the pattern forms the two half flanges on the cylinder 
 and steam chest and also serves to secure the two half cylinders B 
 and C together at their ends, as shown in Fig. 32. It will readily be 
 
24-1 
 
 £.VG/.Y£ PATTERS S 
 
 seen that two of these flanges will be required, one right hand and 
 the other left hand, together with their respective core prints. These 
 core prints are built up, turned and attached to the flange D, as shown 
 in Fig. 36. 
 
 Fig. 42. Plan of Core Box for the Steam Chest 
 
 The parts E and F are shown in Fig. Z7 and simply consist of 
 the half facings and core prints which are attached to the base of 
 the pattern A for completing the flanges and core prints. Two of 
 each of these will be required, one for each end of the cylinder and 
 one for each end of the steam chest. 
 
PISTOX VALVE CYLINDER PATTERNS 
 
 25-1 
 
 After having secured parts B and C in their correct position upon 
 the base A and fastened them together with the flanges D, our atten- 
 tion is next turned to the getting out of the steam ports. One of these 
 steam ports is shown in Fig. 38, and it is designated as part G of the 
 assembled pattern, Fig. 31. Two of these parts are required, one 
 right and the other left hand. Each one of these patterns is constructed 
 in three pieces as shown. 
 
 Fia. 43 
 
 Section A-V 
 
 Fig. 44 
 
 Section A- V 
 
 Fig. 43. Section of Core Box Fitted for Top Half of Core 
 Fig. 44. Section of Core Box Fitted for B6ttom Half of Core 
 
 On account of the irregular form of these steam ports, the largest 
 portion of which extends from the center steam chest over to the 
 cylinder, it will be found convenient to glue up a solid block and then 
 saw it to form, rather than to attempt any form of built up construc- 
 tion to save material. 
 
 Having glued up two rectangular blocks of the required dimen- 
 sions they are laid out and sawed to conform to the diameters of the 
 cylinder and steam chest and fitted down into their correct position. 
 
26-1 
 
 ENGISE PATTERS S 
 
 Next, the two separate parts shown at the left of the figure are 
 built up of segments fitted around and secured to the steam chest with 
 loose dowels. After the above parts have been gotten out in this 
 manner their outline is carefully laid off, the parts removed and sawed 
 and dressed to size, when they are returned to their position. 
 
 The exhaust chamber or part H of the pattern is shown in Fig. 39. 
 This is built and turned up and then sawed so as to fit down in place 
 as shown in Figs. 31 and 39. 
 
 Fig. 45. Core Box for One-Half of Base 
 
 With the getting out of the two stiffening ribs as shown in Figs. 
 40 and 41 the pattern is practically completed. 
 
 Core Box Construction 
 
 The core box for the steam chest is illustrated in Figs. 42, 43 
 and 44, it being so constructed that it forms one-half of the entire 
 steam chest core, together with the port openings. The core being 
 symmetrical about the center line A-W permits of its being reversed. 
 This core box will form the two half cores required with the use of 
 the change in outline of the bottom of the port openings, the provision 
 for which will be described later. 
 
PISrOX I'AIJ-E CYLINDER PATTERXS 
 
 27-1 
 
 By examining the cross section of the cylinder as shown in Fig. 
 29 it will be observed that the top and bottom outlines of the port do 
 not correspond. This necessitates a slight change in the core box at 
 these two points. In Figs. 43 and 44 are shown two cross sections of 
 the core box on the line A-V, with its two sections showing the two 
 different outlines of the port and the loose filling pieces required for 
 altering their form. The upper section A-V shows the core box set 
 up for the upper half of the core as shown in the completed mold, 
 Fig. 49. The lower section A-\ is arranged for the lower core as 
 shown in the mold, Fig. 49. 
 
 rifj. 47 
 
 Fiy. 48 
 
 Section A-O 
 
 Fig. 46. Core Box for Exhaust Chamber Fig. 47- Core Box for Holding^ Down Bolt Lugs 
 Fig. 48. Core Box for OpeninH' for Relief ^'alve 
 
 In constructing this core box the cross stringers are first gotten 
 out, laid ofif and sawed to form to receive the lagging A-T. The 
 stringers are next lined up and rigidly secured together by bottom 
 and end cleats or by braces as shown. The lagging is applied and 
 dressed out in the usual manner. The box is then completed by filling 
 in the two spaces A-U with the required loose material somewhat 
 after the manner illustrated. This loose material or series of loose 
 pieces is intended to form the outline of the port openings. 
 
 A plan and cross section of the core box used in forming one-half 
 of the core for the base, which also forms the outside of the cylinder 
 and steam chest, is shown in Fig. 45. It will be observed that by 
 having two pieces, A-S, of opposite hands, that is, right and left, and 
 also two pieces, A-R, right and left, together with right and left pieces 
 A-Q and A-P, it is possible to set up our box for either one of the 
 two cores required. The box or frame is constructed rectangular in 
 form, the two sides being cut out to conform to the outer dimensions 
 
28-1 
 
 ENGIXE PATTERXS 
 
 of the cylinder and steam chest. To provide for the fiaring sides of 
 the base the material A-N and A-M is placed in the two ends of the 
 box as shown. The box is rammed up in the position shown and the 
 top struck off with the straightedge to conform to the sides of the 
 box. The parts are then withdrawn from about the core and the 
 latter dried upon the plate upon which it was rammed up. 
 
 The core box for forming the exhaust chamber core is shown 
 in Fig. 46, tw'O half cores being made from this box. By examining 
 Fig. 29 and the cross section ot the completed mold, Fig. 49, the man- 
 ner in which this core cuts through into the steam chest will be seen. 
 Some special provision is required at this point to take care of the 
 
 Fig. 49. Cross Section of Mold 
 
 irregular form of the core, and the material A-L is dressed up equiv- 
 alent to the inner diameter of the steam chest at the point at which 
 the exhaust core cuts through into the steam chest. This material is 
 dropped through into the core box and secured with loose dowels 
 as shown. Provision for the rounded corner A-K is made by cutting 
 down into the box as shown. The depression not in use is stopped 
 off or filled up before ramming the core. 
 
 The half core box for forming one-half of the holding down bolt 
 core is shown in Fig. 47, while one-half of the core box used for 
 forming the relief valve opening is shown in Fig. 48. To assist in 
 the setting of this latter core in its proper position the core print and 
 core box are flattened off as shown at A-J. 
 
PISTOX J' AWE CYLINDER PATTERNS 29-1 
 
 The bore or barrel core for the cyhnder is usually made in halves, 
 with the aid of a core frame, or is struck up by the aid of heads secured 
 to the core bar, the parts being subsequently bolted together through 
 the core bar, as is shown in the center core, Fig. 49. 
 
 Molding the Pattern 
 
 A cross section of the completed mold on the line D-D-D-D, Fig. 
 27, is shown in Fig. 49. This shows the method of parting the mold 
 very plainly and also the method of setting the cores and the arrange- 
 ment of the parts of the flask. The mold employed is what is known 
 as a skin dried mold, that is, it is rammed up with green sand, the 
 surface of the mold blackened as would be the case in a dry sand 
 mold, and then the surface dried previous to pouring. 
 
30-1 ENGIXE PATTERNS 
 
 CHAPTER IV 
 
 PATTERN FOR A DOUBLE PISTON VALVE CYLINDER 
 
 In Chapter II the author discussed the pattern work and two 
 methods usually adopted in molding a low pressure slide valve cylinder 
 of the marine type, together with the necessary sweeps required in 
 forming the barrel of the cylinder and the bore or barrel core. In 
 this article he will describe the general construction of the com- 
 l)lete pattern for a double piston valve intermediate cylinder, with 
 core boxes and the arrangement of the sweep for forming the bore 
 or barrel core. 
 
 Pattern Construction 
 
 The position of this pattern during the operation of molding is 
 with its feet up. Cylinders of this type are frequently used on quad- 
 ruple expansion engines, and quite often reach such proportions that 
 the sweeping of the barrel becomes an object, on account of the saving 
 of material and floor space in pattern storing, and in such cases they are 
 usually dealt with after the manner of the low pressure cylinder de- 
 scribed in the former article. 
 
 Three views of a cylinder of this design are shown in Figs. 50, 
 51 and 52. Fig. 50 shows a half vertical section through the center of 
 the cylinder and steam chest. Fig. 51 shows a half section and half 
 plan of the cylinder, while Fig. 52 shows a half end elevation and half 
 section through the valve openings. 
 
 In beginning the work, it is essential to lay out a full sized plan 
 and vertical section through the barrel and steam chest. The usual 
 allowance for contraction is 1-12 inch per foot. Considerable board 
 space can be saved if these views are laid out over each other and their 
 outlines traced with difi^erent colored crayon or shellac so that they 
 may be readily distinguished from one another. 
 
 The manner of building up the first section of the pattern contain- 
 ing the inclosed head of the cylinder, the stuffing box, feet, and a 
 portion of the steam chest, is shown in Figs. 53 and 54. The web A 
 is gotten out with a form coinciding with a section of the barrel and 
 steam chest at this point. The ring B, containing the lower cylinder 
 flange, is built up, turned, and placed uixm the web. The portion 
 of the steam chest containing the lower steam chamber with the nozzle 
 is now built on and up to the ring. The material used in closing the 
 top of this ])ortion of the pattern being of the required thickness, is 
 allowed to project outward so as to form the flange of the steam chest. 
 
DOUBLE PISTON VALVE CYLINDER PATTERN 
 
 31-1 
 
 The stuffing box is turned up with a loose flange, which is cut in sec- 
 tions and held with loose pins, so that these sections can be drawn in. 
 The ribs are usually attached to the stuffing box, forming a loose 
 spider, which is doweled in place, allowing it to be lifted off with 
 the web. 
 
 Figr. 50. Half Vertical Section and Half 
 Elevation of Cylinder 
 
 Fig- 51 Half Section and Half Plan of 
 Cylinder 
 
 Fig. 52. Half End Elevation and Half 
 Section Through Valve Openings 
 
 ^1 m i 
 
 I '-^iiinSai'-J- S 
 
 ^ 
 
 Fig. 50 
 
 Fig. 52 
 
 The patterns for the feet are made in two sections and doweled 
 together, the parting being in line with the top face of the cylinder 
 flange. The cope portion is provided with a loose flange which allows 
 the central portion to be drawn first and the projecting portions of the 
 flange to be picked in afterwards. The part of the feet extending 
 down the barrel is secured to this portion of the pattern from the 
 inside with loose pins and screws. A partial section of the barrel is 
 shown in connection with the first section of the pattern in Fig. 55, the 
 barrel being broken away in two places in order to shorten it up. 
 
32-1 
 
 ENGINE PATTERNS 
 
 It will be noted that there is a parting along the line C F F. The 
 barrel of the cylinder is made up by building up rings, turning them 
 and lagging these over. If the lagging is sawed quite narrow, it will 
 require very little fitting and can be gotten out to the required thickness 
 and then dressed off with a very small amount of work after it is in 
 position. 
 
 Fig. 53. Half Plan of Cylinder Pattern 
 Fig. 54. Section of Top of Pattern 
 Fig. .55. Partial Section of Barrel 
 
 Fig. 55 
 
 At the bottom of the pattern there is a flange which is parted from 
 the lagged up portion as shown, the flange being built up, turned and 
 doweled in place. In order to reinforce the portion of the cylinder 
 opposite the counter bore at each end, it is necessary to introduce the 
 lagging shown at H, at the top and bottom of the barrel. That at the 
 top is secured to the barrel so that it will draw with it, but that at 
 the bottom must be attached with loose dowels so that it may be picked 
 in after the pattern is drawn. 
 
 Two views of the steam port section of the steam chest are shown 
 in Fig. 56, two of these parts being required. They are generally 
 gotten out as shown, the sides being made up of segments and the top 
 and bottom closed in. 
 
DOUBLE PISTON VALJ'E CYLINDER PATTERN 
 
 33-1 
 
 The exhaust chamber section of the steam chest is shown in plan 
 and section in Fig. 57, the manner of construction being clearly 
 shown. As will be noted the sides are lagged up over ribs built up of 
 segments and cut out to the form of the outline of the pattern. 
 
 The exhaust nozzle I, with its core print, is also shown attached 
 by screws and loose pins from the inside. Three views of the upper 
 steam chamber section of the steam chest are shown in Fig. 58, to- 
 gether with the steam nozzle J, which is attached with loose dowels. 
 This' part of the pattern is built up of segments and the side forming 
 the top closed with material corresponding in thickness to the required 
 thickness of the flange, the material being allowed to project over and 
 form the flange as shown. On account of the fact that the steam 
 
 Fig. 56 
 
 Pig. 57 
 
 Flange 
 
 Fig. 68 
 
 Fig. 56. Plan of Steam Port Section of Steam Chest Fig. 57. Exhaust Chamber Section of Steam Chest 
 Fig. 58. Upper Steam Chamber Pattern 
 
 ports are of a greater width and that they pass partially through the 
 steam chamber, it is necessary to extend this portion of the pattern as 
 shown at K. 
 
 The assembled pattern is shown in Fig. 59, in the reverse position 
 to that which it occupies in molding, but in the position which it 
 occupied during the building. After the different parts are complete, 
 the first section containing the inclosed cylinder head, etc., is blocked 
 up upon the floor as shown. The barrel is placed in position upon it 
 and secured with dowels. The various sections of the steam chest are 
 then placed one upon another, each being located in its proper relation- 
 ship to the others, by means of suitably placed dowels. 
 
 The rib L, which connects the exhaust chamber with the barrel, 
 and which is also shown in Figs. 50 and 51, is made with a joint 
 lengthwise through its center, so that one-half of the rib can be 
 
34-1 
 
 • EXGIXE PATTERNS 
 
 drawn each way. that is. one-half into the barrel and the other half 
 into the exhaust chamber. This is necessary on account of the open- 
 ings in the rib, as shown in Fig. 50. 
 
 Core Box Construction 
 
 The core box used in forming the steam chamber, is shown in Fig. 
 60, the sides being built up of segments, worked out to the proper 
 form, doweled to the bottom board and parted as shown. This allows 
 the bottom to be lifted off when the box is rolled over the sides to be 
 drawn back, and the loose piece drawn out. 
 
 Fig. 59. .Assembled Pattern 
 
 The cores forming the steam chest must of necessity be placed 
 one upon another when coring the mold, as shown in Fig. 63. and the 
 vent taken off from one core to another and out through the cope. 
 To facilitate the location of these cores in their proper relationship 
 one to another, and to assist in carrying the vent from one core to 
 another, a projection is made on the bottom of each core and a corre- 
 sponding depression in the top of the one below to receive it, thus 
 forming a male and female joint between the cores. The arrange- 
 ment of the core box to form the projection is shown at R, Fig. 60, 
 while the print forming the depression is shown in dotted lines at S, 
 Fig. 61. These projections and depressions must be reversed from the 
 bottom to the top of the boxes, as the case requires. 
 
 The plan and section of the port core box, with the arrangement of 
 sweeps for forming the outer surface of the circular portion of the 
 core, are shown in Fig. 61. This box is constructed as shown, with 
 the projecting arm or bracket, to which the sweep is secured with the 
 center pin. In the course of ramming up the fiat portion of this box, 
 a board with an opening to form the projection or print is secured to 
 
DOUBLE PISTON J'ALJ'E CYLINDER PATTERN 
 
 35-1 
 
 the box as shown by the dotted hnes at X. After the flat portion of 
 the core has been completed, this board is removed, the sweep set 
 in place, and sand rammed in against the circular portion of the box 
 and struck off with the sweep. By referring to Fig. 63, it will be 
 noticed that the two cores made in this box meet the barrel core in 
 a different manner, that at the top having a projection which laps 
 
 SECTION MN-O-P 
 
 Figr. 60 
 
 SECTION T-U-V-W 
 
 Fig. 61 
 
 Fig. 62 
 
 SECTION AA-AA 
 
 Fig- 60. Core Box for Steam Chamber. Fiff. 61. Port Core Box 
 Fig. 62. Core Boxes for Exhaust Chamber, Feet and Exhaust Opening 
 
 over the end of the bore, while the lower core abuts squarely against 
 the barrel core. To provide for the making of the lower core, it is 
 necessary to furnish a stop-off piece to stop off the core on the dotted 
 line Z. 
 
 A plan and cross section of the core box used in forming one-half 
 of the exhaust chamber are shown at the left of Fig. 62. The drawing 
 gives the general method of construction and shows the manner in 
 which the rib is drawn out before the box is rolled over and taken apart. 
 
 The foot core box is shown by three views in the upper right hand 
 corner at Fig. 62. and it will be noticed that the top is struck off, the 
 strike being shown below the core box. 
 
 The core boxes for making the exhaust opening and the covering 
 core used in connection with it are shown in the lower right hand 
 corner of Fig. 62, and the construction and use will be evident from 
 the drawing. 
 
 Method of Molding 
 
 The molding is carried on as follows. The foundation plate F, 
 Figs. 63 and 64, is placed in position and leveled up. The pattern is 
 then blocked up upon the same and the space below the pattern filled 
 
36-1 
 
 ENGINE PATTERNS 
 
 with brick, with a thickness of loam against the surface of the pattern. 
 An off set parting is prepared parallel with the edge of the flange, and 
 at a short distance from it, as shown at P. A lifting plate of proper 
 form is provided and placed upon this parting as shown at K, and the 
 brick and loam work continued up to the lower port chamber, as 
 shown at G, Fig. 63. 
 
 By referring to Fig. 50, it will be noticed that the form of the port 
 chambers and the way they fit into the side of the barrel makes it 
 necessary to form this portion of the mold upon cheek plates, as in- 
 
 Fig. 63. Section of Completed Mold 
 
 dicated by the dotted lines C, Fig. 51. An offset parting for this 
 plate is made upon the surface G, Fig. 63. From the ends of this 
 cheek plate it will be necessary to carry up a vertical parting clear 
 to the top of the mold, this vertical parting extending on a radial line 
 from the barrel of the cylinder. The brick work is then continued 
 until the upper port chamber is reached, where it is necessary to make 
 another parting,. as shown at H, and place another cheek plate, similar 
 to that placed upon the parting G. T'iC brick work is then continued 
 to the top of the mold at I, and a parcing prepared for the cope which 
 is rammed up in dry sand in an ordinary iron flask. 
 
DOUBLE PISTON I -AWE CYLIXDER PATTERN 
 
 37-1 
 
 After the mold is completed, the cope is lifted off and the first 
 section of the pattern containing the inclosed cylinder head is drawn. 
 This gives access to the interior of the barrel and allows the pins and 
 screws securing different parts of the pattern to the barrel to be re- 
 moved. The barrel is then drawn. The cheeks are then lifted away, 
 and the different sections of the steam chest pattern behind them 
 drawn as they are exposed. The plate K, which supports the outer 
 wall of the cylinder and the lower section of the steam chest and 
 cylinder flange, is then lifted off and while suspended the lower por- 
 tion of the pattern is drawn down from it. 
 
 Fig. 64. Sweeping the Core for Cylinder 
 
 The parts of the mold which have been removed are then placed 
 in the oven to dry and the spindle is located in the center of the 
 cylinder for sweeping the barrel core, as shown in Fig. 64. The barrel 
 core is swept up with brick and loam in the usual manner. The lower 
 arm B-B (shown by dotted lines) is removed when the brick work 
 reaches this height, and the completed portion of the sweep surface 
 is used as a guide for the lower end of the sweep. A cast iron plate 
 is placed on top of the brick walls, close to the top, and the upper 
 surface finished as shown, with the seat or print swept in the center 
 to receive the stufBng box core. 
 
 The stuffing box core is shown in detail to the left of the upper 
 part of the spindle in Fig. 64. The barrel core supported by the 
 plate is now placed in the oven and dried. 
 
38-1 EXGIXE FATTERXS | 
 
 The assembling of the mold is as follows : The foundation plate 
 1\ with the barrel core and the seat upon it, is lowered into the pit 
 and leveled up. The plate K supporting the outer wall of the barrel 
 
 is next placed upon it. The cores and cheeks forming the steam j 
 
 chest are now lowered into place in their proper position. '• 
 
 The nozzle cores are inserted from the outside of the brick work ' 
 
 through openings left for the purpose, and the openings closed with ] 
 
 the covering cores. i 
 
 The gates and runners are prepared during the building of the 
 
 mold, the cope placed in position, and the intervening space between \ 
 
 the mold and the pit wall firmly packed up by ramming in sand. i 
 
 The cope is then weighted or bolted down, when the mold will be ' 
 
 complete and ready for pouring. I 
 
HEAVY BED PATTERNS 39-1 
 
 CHAPTER V 
 
 PATTERNS FOR A HEAVY ENGINE BED 
 
 Engine frames or beds assume various forms, being chiefly de- 
 signed to suit the work and requirements in each particular case. 
 Shown in the accompanying illustration is a familiar form of a heavy 
 duty, or what is sometimes termed the Allis type of bed. This form 
 is especially adapted to heavy mill work, and the engines are frequently 
 made and connected up in pairs, the dimensions assuming large pro- 
 portions. 
 
 The one under discussion is the right hand bed of a pair of 
 reversible, piston valve blooming mill engines. The general practice 
 with concerns building engines of this type is to construct the bed 
 patterns so that they will serve for both right and left beds, and also 
 for engines of different strokes. There are a number of different ways 
 in which a pattern of this nature can be constructed, and it may be 
 difficult to decide which is the most practicable and economical both 
 for the patternmaker and the molder, for in all such work both the 
 patternmaking and the molding should be taken into consideration. 
 
 As the duplication of these bed castings is frequent with concerns 
 doing this class of work, the construction of a complete pattern is 
 usually considered the most economical. 
 
 Construction of the Patterns 
 
 The pattern can be constructed to serve for both the right and left 
 bed somewhat after the manner illustrated and described in this 
 article. Fig. 65 shows the plan and elevation of the bed showing its 
 general outline and the metal distribution. It also shows the points 
 at which the cross sections illustrated in Figs. 67, 68, 69, 71, 72 and 73 
 were taken. These cross sections should receive close attention from 
 the patternmaker, in order that he may obtain a thorough knowledge 
 of the requirements in making up the core boxes. 
 
 Viewing the frames from the front it would appear as illustrated 
 in Fig. 66, while the cross section on the lines AA, BB and CC would 
 appear as shown in Figs. 67, 68 and 69. Fig. 70 shows the outline 
 of the back or cylinder end of the frame, while Figs. 71, 72 and 73 
 illustrate the cross sections on the lines DD, EE, FF as they would 
 appear from the cylinder end. 
 
 Of course, the first thing would be for the patternmakers, foun- 
 drymen and others interested, to get together and thresh out the 
 
40-1 
 
 EXGIXE PATTERXS 
 
 Fig. 65. Plan and Elevation of a Large Engine Bed 
 
HEAVY BED PATTERNS 
 
 41-1 
 
 general discussion of the molding, shrinkage, arrangement of cores 
 and the construction of the pattern. When this has been done a full 
 sized layout giving both the plan and elevation with core outline or 
 metal distribution is essential. It is also necessary to draw a number 
 
 a 
 
 Fisr. 66. Front End View 
 
 Fig. 67. Section A A 
 
 Fig. 68. Section B B 
 
 Fig. 69. Section C C 
 
 of cross sections, say for instance, AA, DD, EE and FF. To econ- 
 omize the layout board surface, these layouts can be made over one 
 another and dotted in with different colored crayon or shellac, which 
 will enable the workmen to distinguish one section from another with- 
 out difficulty. The shrinkage usually allowed is 1-12 of an inch per 
 foot, with a liberal allowance for finish upon all machined surfaces. 
 
 It might be well to state that in the construction of large patterns 
 the closer the exact dimensions are worked to, the easier will the work 
 
42-1 
 
 ENGINE PATTERNS 
 
 be comp eted. That is, allow scarcely any material for dressing to size. 
 Place what draft is desired upon the frames, and inclose them with 
 the required thickness of material. Then the only work necessary is 
 the cleaning and sandpapering of the pattern. 
 
 Fig. 71. Section F F 
 
 Fig. 70. Back End View 
 
 Fig. 73. Section D D 
 
 Fig. 72. Section E E 
 
 To facilitate the altering of the pattern for different strokes, as 
 well as the handling and storing of the same, it is built in sections and 
 assembled as illustrated in Fig. 74, which shows the general construc- 
 tion, the joints of the various sections or parts, together with their 
 attached core prints, loose pieces, etc. 
 
44-1 
 
 ENGINE PATTERNS 
 
 To aid us in referring to the different sections or parts during a 
 discussion of their construction, let us designate them as sections 1, 2, 
 3, etc. Sections 1, 2, 3 and 4 comprise the forward or bearing portion, 
 while sections 5 and 6 comprise the cross head housing, and part 
 7 the bracing member. 
 
 As section 1 usually receives the initial attention, let us proceed 
 with its construction as shown in Fig. 75. This section, together 
 with sections 2, 4, 5 and 6, are used for both right and left hand 
 beds. It will be observed that in using this section for both right and 
 left hand patterns it is necessary to make right and left hand corner 
 pieces G and H, and also to provide for the reversing of the strips 
 forming outline of the crank-pit core print I, and the covering material 
 J, Fig. 75. 
 
 ^Covering tt 
 
 Fig. 75. Section 1 of Pattern 
 
 The frames can be gotten out, secured together, and the sides 
 inclosed somewhat after the manner illustrated. Offsets are formed 
 on the line KK to receive the right and left hand corners G and H, 
 which are next built in place and secured with dowel pins and screws. 
 The covering material J is next added, and the strips forming the 
 outline and thickness of the core print I attached. This manner of 
 forming this core print answers the purpose very well, and permits of 
 an opening through the pattern to facilitate the ramming of the 
 mold. In closing the bottom N, the material can be cleated together 
 in two or three sections, which permits of its easy removal giving 
 occess to the interior for the withdrawal of the screws and pins, and 
 for the rapping and drawing of the pattern. 
 
HEAVY BED PATTERNS 
 
 45-1 
 
 Fig. 76 shows a plan, elevation and end view of section 2 of the 
 pattern. The frames O, as shown in the end view, are nailed and 
 screwed together, and covered with stock to form the required outline. 
 As this section is employed for both right and left hand patterns, it is 
 necessary to make an offset on each side along the lines LLL. This 
 space is then filled with a right and left hand piece shown above and 
 to the right of the other views. The right hand piece being shown in 
 place in Fig. 76. 
 
 Next the core print M is attached, a section of which is shown 
 in greater detail to the right of the plan. Attention is called to the 
 strip P around the outer edge of this print. The strip being added 
 to assure a perfect setting of the core, for any sand disturbed in the 
 placing of the bearing core in position, will fall down below the seat of 
 the core and into the depression left vacant by the strip P. 
 
 Loose 
 
 Fig. 76. Section 2 of Pattern 
 
 The loose facings and the holding down bolt lugs, having been 
 gotten out are attached with loose dowels, and this section is then 
 ready to be placed in position upon section 1, the two parts being 
 secured together M'ith dowels and screws. These dowels and screws 
 must be so arranged that they are get-at-able when the bottom is 
 removed from section 1. 
 
 It is next necessary to construct that part of pattern designated 
 as section 3, as shown in two views and a section on the line QO in 
 Fig. 77. For this section it is necessary to build a complete right hand 
 and a complete left hand piece. Owing to the irregular form this 
 section is the most difficult to construct, and it is advisable to build 
 it in its correct position upon section 1, with the end fitting against 
 
46-1 
 
 ENGINE PATTERNS 
 
 section 2, as shown in Fig. 74. First the lower part of the core print 
 to the center line or height R, and with a width equal to S, is framed 
 up and the top and end closed in. The projection which fills in the 
 offset on the line LL of section 2, built up as shown at Y. The arch 
 frames T and U are now gotten out and placed in their correct 
 position. These frames differ in form, frame T being of an elliptical 
 shape, while U is circular. As the required opening is given through 
 the rib D, section 1, it will be found convenient to locate frame U 
 
 Section O-O 
 
 Figr. 77. Section 3 of Pattern 
 
 at this point and lay it out accordingly. Of course, allowance must 
 be made for the round corner CX, Fig. 65, which would make the 
 core print that much larger in diameter. The lagging is now placed 
 on and dressed to its proper form. Frame W is then set in position, 
 and the width X built up to the point of tangency with radius ^. 
 Lagging a is now fitted on, dressed to form and the fillet h worked 
 out. 
 
 Section 5 as shown in plan and cross section in Fig. 78 forms the 
 cross head housing, and is used in both right and left hand patterns. 
 The use of this piece for both right and left hand patterns necessitates 
 
HEAl'Y BED PATTERNS 
 
 47-1 
 
 the building of oblong openings in each side, the one not in use being 
 closed or stopped off by the bracing member or section 7, Fig. 74. 
 It will be observed that this part of the pattern is built the full height 
 and secured to the end of sections 1 and 3 with pins and bolts. The 
 frames are usually gotten out as shown in the cross section de. These 
 frames are lagged over forming the depression c on the sides. This 
 depression has a depth equal to the metal thickness which allows the 
 core to cut through when placed in the mold. The oblong openings 
 are now built in with that portion above the center, as shown at g 
 secured wath pins, so that it may be drawn in after the pattern is 
 removed from mold. 
 
 Fig. 78. Section 5 of Pattern 
 
 The cylinder end of section 6, is shown in two views in Fig. 79. 
 This portion is used for both right and left hand patterns with prac- 
 tically no change. The frames, two in number, are gotten out and 
 secured together. It will be observed that the outer one, as shown 
 in the end view, is partially closed, leaving a square opening to be cov- 
 ered with the attached core print. 
 
 These two frames are lagged over, provision being made to secure 
 the loose pieces HI which are left detached from the pattern to facil- 
 itate its drawing from the sand when checking off this portion of the 
 pattern. These loose pieces are next fitted in place and secured, when 
 this portion of the work receives its dressing up, corners rounded, etc. 
 
48-1 
 
 EXGIXE PATTERXS 
 
 The core print, one-half of whicli is shown in two views, Fig. 80, is 
 staved up, the forms being gotten out and covered with lagging and 
 turned in halves, the lower or drag half is secured in its proper position 
 to section 6 with screws and loose dowels, and the upper half placed 
 upon the lower half. Segments forming the loose facings JK are next 
 attached when this section will be ready to secure to section 5, as 
 shown in Fig. 74. 
 
 Section 7 — or what is sometimes termed the bracing member, is 
 shown in three views. Fig. 81. It is necessary to make both right and 
 left hand patterns for this. The section is built in its proper position 
 to the assembled sections, as shown in Fig. 74, the frames having been 
 
 Iioose^y 
 
 Fie, 79. Section 6 of Pattern 
 
 Fig. 80. Core Print for Cylinder 
 End of Pattern 
 
 nailed up with ample stock allowed for fitting and sawing to size. 
 They are fitted to the sections 2, 3 and 5 and secured in place with 
 screws and pins. 
 
 The proper outline of the section is next laid ofT upon them; 
 they are then removed and sawed to size and returned to their proper 
 position, where they are secured and well braced together. The 
 material inclosing the top and side is next placed in position and 
 dressed up, and the core print LM attached. 
 
 The large fillet shown in two views in the lower right hand 
 corner of Fig. 81 is gotten out, and fitted in place up to section 3 
 and worked out to shape. 
 
 With a dressing up and finishing of the assembled sections of 
 the completed pattern, this part of our work is done, with the excep- 
 tion of the crank pit extension, as shown in two views in Fig. 82. 
 This is constructed by getting out sides and center rib, securing them 
 
HEAVY BED PATTERNS 
 
 49-r 
 
 together with separating pieces and then lagged up. To avoid the 
 end grain of the material used in the lagging, shown on the sides of 
 the pattern, the sides are gotten out of the required form, and the 
 lagging fitted so as to butt against the inside of these pieces, that is, 
 to fit between them. This necessitates a segment, which forms a 
 shoulder to receive the lagging, and is placed in position and secured 
 to the inside of the side pieces. The lagging afterwards is placed in 
 position and dressed off to conform to the sides. This section is used 
 for both right and left hand patterns. The one change necessary is 
 the change of its position on section 1. 
 
 Fig. 81. Section 7 ot the Bracing Member 
 
 The holding down bolt lugs, etc., are now fitted to the assembled 
 pattern. The various sections given designating marks, so that they 
 can be returned into their proper relationship one to another, after 
 which the pattern is dismantled and set up in a reverse position as 
 required for the left hand pattern, the various left hand sections built 
 in just as the right hand sections were. 
 
 Construction of Core Boxes 
 
 The core boxes, fifteen in number, next claim our attention. For 
 convenience in referring to the various core boxes employed in form- 
 ing the interior of the frames they are designated, Al, A2, A3, etc., 
 the location of the cores being shown by the letters placed on Fig. 65. 
 
50-1 
 
 ENGIXB PATTERXS 
 
 As the most of these boxes are of simple construction, we will illustrate 
 only those, with the exception of A3, receiving core print settings. 
 The ones illustrated embrace the most intricate boxes in the set. All 
 of the boxes are made of rectangular form, and are all employed for 
 making both right and left hand cores. The form of the cores and 
 changes from right hand to left hand being made by changing the 
 position of the filling in pieces, or by the use of right and left hand 
 sections of the boxes. 
 
 We will first consider the construction of the boxes used in form- 
 ing core Al. This core forms the upper half of the interior of the 
 cross head housing, and is supported in the mold by its projecting 
 core prints, as shown in Fig. 74. This box is, with one exception, the 
 
 Fig. 82. Crank Pit Extension Pattern 
 
 largest and most intricate box to construct. It is shown in plan and 
 longitudinal section through the center, and a cross section on the 
 line LM, in Fig. 83. 
 
 Material of about 2>4 inches by 6 inches for forming the rect- 
 angular frame is first gotten out and secured together in a good sub- 
 stantial manner, about as shown. The cylindrical part forming the 
 projecting print portion at the right of the figure can be staved up 
 and dropped into place. The board forming the taper on the end of 
 the print is fitted in separately. The segments forming the depression 
 () are now nailed up, layed off, sawed out, dressed to the proper 
 form, dropped into place and secured, and the staving up of the barrel 
 proceeded with. 
 
 The depression R is also built up of segments, dressed out and 
 fitted in place. It will be observed that a slight change is required 
 at the top of the box at this point, for the right and left beds, and 
 
HEAVY BED PATTERNS 
 
 53-1 
 
 that this necessitates the changing of the blocks S and T. The cross 
 head guide U is now lagged in with the shoulder V arranged as 
 shown to support its projecting end, or loose piece W. This loose 
 piece W must be drawn back out of the core after the removal of 
 the boxes. As the remaining portion of the box cannot be used for 
 
 Fig. 85. Core Box A 3 
 
 Hectioii Ji D 
 
 both right and left hand patterns, it becomes necessary to construct 
 a full right and a full left hand section for the portion marked X. 
 
 The core print portion having been lagged up and dressed out 
 to conform to the core print of the pattern, the outline of the round 
 corner is next laid off or transferred to the surface. This can be 
 done very nicely and accurately by placing heavy paper over the core 
 print on the pattern and fitting it up against the rounding surface at 
 the intersection of the core print and the pattern. The paper is then 
 
54-1 
 
 ENGINE PATTERNS 
 
 placed in the correct position in the core boxes, after which the fiUing 
 in pieces or lagging, are fitted to its outline as shown by Z. 
 
 Material is now added from which the pockets AB and AC, as 
 shown in section LM, are worked out. The blocks or loose parts AD 
 and AE are fitted above the pockets AB and AC. 
 
 It will be noticed that these loose pieces AD and AE must be 
 removed and the openings left vacant by them filled in with green 
 sand to support the overhanging projections after the box has been 
 turned over upon the core plate. 
 
 Fig. 86. Core Box A 4 
 
 Section It L 
 
 Section £ JtT 
 
 The board AF is now fitted into the end of the box to give the 
 proper taper to the end of the core. The core print AG which is 
 suspended from the top of the box is located and doweled in place. 
 This core print AG forms the interior setting for the oblong core 
 A15, which passes through the core A14 intended to form the interior 
 of the bracing member. This core print is made longer than the 
 setting of the cores requires owing to the fact that the core has to 
 be placed in the depression left vacant by the core print, and then 
 shoved forward through the core A14 and into the impression left 
 by the core print on the pattern. The portion of the core print left 
 \'acant after the core A15 has been shoved to its final position may 
 be stopped off with sand. 
 
 This completes the core box for the right hand bed. In making 
 the changes for the left hand bed it is necessarv to build a left hand 
 
HEAVY BED PATTERNS 55-1 
 
 section X, and to get out pieces S and T of the opposite hand. It is 
 also necessary to change the beading P around the oblong openings 
 in the side of the cross head housing to the opposite side of the box. 
 The suspended core print AG is also changed from one side of the 
 box to the other. 
 
 Fig. 84 shows a plan, a longitudinal section through the center, 
 and a cross section on the line AH of the core box used in forming 
 the core A2. This core when placed in position upon core Al com- 
 pletes the interior of the cross head housing, and also the exterior part 
 of the bed leading down into the crank-pit. While this illustration 
 is almost self-explanatory a few remarks may not be out of order. 
 The frame is constructed about the same as for the box previously 
 described, and the filling-in sections made, dropped into place and 
 secured to the frame. It will be observed that the only two sections 
 employed for both the right and left hand beds, are the center section 
 or that part which contains a cross head guide, and the round core 
 print HI. With the two parts HI, and the part for the cross head 
 in place, the bottom board Y is fitted in, and the side pieces AJ and 
 AK dropped into place upon it. The side pieces for the center section 
 having been gotten out and secured in place, the change pieces AL 
 and AM are fitted in, as well as board AR, which contains the circular 
 opening at the forward end of the housing. With the suspension of 
 the core print AG, which can be used in both boxes Al and A2, 
 the getting out of the beading AS around the oblong opening on the 
 side of the housing, which matches the beading of the core box shown 
 in Fig. 83, this portion of our box is completed and the lagging in 
 of the section AO proceeded with. Owing to its irregular form and 
 the provision which has to be made for taking care of the rounding 
 corner AT, it will be found convenient to make the section in four 
 pieces and join them at AU and the sides along the line AV as shown. 
 
 Core A3 which forms the metal thickness of that portion of the 
 frame directly forward of the cross head housing is made in the core 
 box shown in plan and two cross sections in Fig. 85. This is a 
 large cumbersome box for making a comparatively light core which 
 is due to the built up form BE, which occupies the greater part of 
 the box interior and conforms to that part of the frame extending 
 down into the crank-pit. Of course, in constructing this part of the 
 box, allowance is to be made for the metal thickness. Practically 
 none of this box can be used for the opposite hand bed except the 
 frame, which is put together as shown. The form BE is lagged up 
 ever supports, dropped into place and secured with pins. The material 
 forming the outline of the sides BF and BG is gotten out and fitted 
 
56-1 
 
 ENGIXE PATTERNS 
 
 in position. Referring to the cross section CC as shown in Fig. 69, 
 which gives the exact outline of the core required, it will be seen 
 that the filling in pieces BH and ]]I are required to form the desired 
 height and outline of the upright projections as shown in Fig. 85. 
 This box is completed by placing in position the internal flanges Bf 
 and the metal thickness around the holding down, bolt boss BK. 
 
 The plan and two cross sections of the core boxes used for form- 
 ing the core A4 for the crank-pit, are shown in Fig. 86. This box 
 
 Fig. 87. Core Box A 5 
 
 Section B-O 
 
 consists of a frame the sides of which conform to the desired height 
 and form of the core, the box being rammed up. struck off and the 
 pieces BN and BO which support the part of the fillet extending into 
 ths core bedded in. It will be observed that this fillet is the continu- 
 ation of the fillet formed in the core box A2, and which runs out at 
 this point in the crank-pit. 
 
 To avoid the sharp corner around the side and end of the pit. 
 an offset as shown at BP is arranged for. 
 
HEAVY BED PATTERNS 57-1 
 
 Core A5 which forms the main bearing, is made in the core box 
 shown in Fig. 87, the box being constructed somewhat after the 
 manner iUustrated. After the frame is completed the material RS 
 forming the T head facings is made and held in place with loose pins. 
 To form the openings through the metal on each side of the bearing 
 material, the thickness of which is equal to the metal thickness, is 
 dressed up and fitted to the box, and the required openings cut out. 
 The facings BT must also be secured to the openings. The circular 
 pieces on top of the boxes are next attached, and to them are secured 
 the two supports for carrying the circular facings BU. 
 
 The seven core boxes or frames used in forming the remaining 
 ten cores are not illustrated, as they are of a comparatively simple 
 nature, so that a description of their general construction and manner 
 of changing from right to left hand will be sufficient. There cores. 
 with one exception, core A15, have no core print setting, being secured 
 in the mold and in their proper relation one to another with chaplets. 
 
 Core AlO forming the interior of the bed underneath the main 
 bearing is made in halves, the two halves being joined together with 
 the vertical plane on the center line of the longitudinal rib. As the 
 core is sxmmetrical about the center of the rib, one-half of the box 
 without any change is all that is required, the two half cores being 
 simply turned over and pasted together. This box consists of a frame 
 and a bottom board, upon which one-half of the thickness of the rib 
 is attached. Xext material giving the circular form at the bottom of 
 the bearing, and to form the internal flange at the bottom, together 
 with the cross rib. is placed in the box. 
 
 Directly in front and back of the main bearing and extending 
 the entire height of the bed are cores A6 and A7. These cores are 
 also made in halves, being parted in the same plane, that is. along 
 the center rib as was the case in core AlO. These four half cores 
 are made from the same frame and upon one bottom board. It will 
 be observed that core A7 is of triangular form, while core A6 is 
 rectangular. As the latter core is the largest the frame and bottom 
 board are made to correspond with its size and filling in pieces used 
 when making the triangular core A7. In ramming up core A7, the 
 bottom of the box forms the joint of the two half cores, while the 
 top of the box forms the joint in core A6. This necessitates the sus- 
 pension of one-half of the thickness of the rib from the top while 
 making core A6. the change being due to the fact that it is necessary 
 to fill in the bottom board with material to obtain the outline of the 
 metal on the sides, also the internal flange holding down both bosses, 
 etc., which are attached to the side of the box. 
 
58-1 ENGINE PATTERNS 
 
 That part of the bed between the crank-pit and the extreme front, 
 and which extends part way down the side of the bed, is formed 
 with tlie core A8. This core is made in a rectangular frame with 
 bottom board, the frame being gotten out the required height and 
 length, and with a width which will allow the placing in of a rec- 
 tangular stopping off board conforming to the angle of the crank-pit 
 end. It will be seen that this stopping off board does not extend the 
 entire length of the box, but only that portion required in forming 
 the metal thickness across the end, and upon a portion of the side 
 of the crank-pit. 
 
 The material forming the internal flange across the end of the 
 bed is now suspended from the top of the boss and the work is com- 
 pleted by placing in upon the bottom board and up to the end of the 
 box, material to form the metal thickness around the holding down 
 bolt. It is also necessary to place a rib on the center line of the bed. 
 This rib separates the core into two parts. The box is rammed up 
 in a reverse position to that shown in the drawing, Fig. 65, that is, 
 upside down. 
 
 Core A9 which forms the portion of the space between the side 
 of the bed and the crank-pit and extends from the core A8 to core 
 A3, with the exception of the distance occupied by the thickness of 
 the ribs, is the next one to be constructed. The ribs separating the 
 cores A8 and A9 are on the same angle as the end of the crank-pit. 
 The box is made of rectangular form, and contains a section of the 
 internal flange along the side of the bed, and one-half of the holding 
 down bolt boss, the other half being formed in core A3. With the 
 exception of the piece to form the angle at the end this box is complete. 
 
 We next turn our attention to cores All, A12, and A13. These 
 three cores are all made from the same box. Owing to the fall or 
 pitch of the metal supporting the cross head guide, the bottom of 
 the box requires considerable change for each core. The box con- 
 sists of a frame with bottom board, and is gotten out in length equal 
 to the width of the bed, plus a convenient allowance for dropping in 
 the lagged up forms, which conforms to the flaring sides at the 
 bottom of the bed, as shown in cross section on the line EE, Fig. 72. 
 The frame is made of sufficient depth to permit the use of filling in 
 pieces upon the bottom board. These pieces give the outline of the 
 cross section of the metal, as well as the proper pitch or fall toward 
 the cylinder end, as shown in the elevation of the bed Fig. 65. The 
 width of the frame is made to correspond to the widest core, which 
 is A12, plus the thickness of the rib, the half thickness of the rib 
 being placed in each side of the box. As cores All and A12 do not 
 
HEAVY BED PATTERNS 
 
 59-1 
 
 extend the full width of the bed, but only to the metal thickness 
 separating this part of the bed from the bracing member, it is neces- 
 sary to use a stop off board to give the core its correct length. The 
 interior flange is placed in at the top of the frame and supported by 
 the lagged up form at the end. The changes required for All and 
 A13 can readily be seen by studying the cross sections and Fig. 65. 
 Core A14 is of triangular shape and forms the interior of the 
 bracing member and a short section of the flarinq; side of the bed at 
 
 Fig. 88. Methods of Molding 
 
 Cylinder End of 
 
 Pattern 
 
 the intersection of the two parts, as shown in the plan view of bed 
 Fig. 65. The core is made entire, being rammed up in a frame with- 
 out a bottom board. The top of the frame corresponds to the angular 
 side of the bracing member. The material forming the internal flange 
 around the bottom of the bed is secured to the side of the box, while 
 the metal thickness around the oblong opening formed by core A15 
 is provided for by an oval block secured to a support across the top 
 of the frame. 
 
60-1 ENGINE PATTERNS 
 
 Method of Molding 
 
 The method of molding is known as the bedding in process, 
 that is, the pattern is rammed up in the floor and the mold subse- 
 quently skin dried. The process may embrace some points of interest, 
 but owing to the limited space, we will discuss only that part shown 
 in the three views in Fig. 88, which, of course, will be molded in 
 the reverse position. This shows two ways of arranging the mold 
 at the top or cylinder end of the pattern. It will be readily seen that 
 the diameter of the cross-head housing core at WX is greater than 
 the width of the mold at YZ, which will not allow the core to be 
 placed in position in the mold without coring or cheeking off the two 
 sides of the mold. There are two ways in which this is usually 
 accomplished. First: Core prints may be attached extending to the 
 rounding of the corner of the pattern, as shown in the full lines, and 
 a dry sand core used. The end of the pattern will be cheeked off, 
 as shown by the dotted lines. 
 
 Second: The cheek may be made in two parts jomed aiong the 
 line VV, shown in a view at the right, and letting it extend around 
 the sides of the pattern to the combined width of the core print and 
 cheek shown. Of course, when this latter method is employed the 
 core prints are not attached. 
 
SECTION II 
 
 MOLDING IN CORES 
 
 CHAPTER I 
 MULTIPLE CORE MOLDING 
 
 As the name implies, this process consists in the grouping or 
 stacking together of a number of cores containing impressions of 
 the object to be cast and so arranged that they can all be poured 
 from one gate. This method of core molding is especially adapted 
 to small steel castings, for in most steel foundries the facilities for 
 pouring light pieces are not of the best. In other words, in steel 
 foundry practice the pouring is usually done from a large bottom 
 pouring ladle and hence it is difficult to pour small molds. The 
 method is also especially applicable in cases where there is not a 
 sufficient number of pieces required to warrant the fitting up of a 
 molding machine. 
 
 Fig 1. Coupling Pin 
 
 This method of core making is remarkably well illustrated by 
 considering the equipment necessary for making the coupling pin 
 shown in Fig. L Another advantage of selecting this particular piece 
 is that is affords an excellent example of the making of plaster pat- 
 terns for the metal core boxes, these plaster patterns being made 
 from the original wood pattern of the pin by a reversing method. 
 
 A plan, elevation and cross section of the bottom plate of the 
 metal core box used in forming one-half of the core are shown in 
 Fig. 2, while Fig. 3 shows a plan elevation and end view of the bot- 
 tom plate used in forming the remaining half. 
 
2-1 1 
 
 MOLDING IN CURES 
 
 The metal plates which form the sides and ends of the core and 
 which are secured to the bottom plate by means of pins in the position 
 shown in cross section on the line W in Fig. 2 and in dotted lines 
 Fig. 3 are illustrated in two views in Fig. 4. In the illustration the 
 frame is shown as arranged for the bottom plate illustrated in Fig. 3. 
 The piece for forming the runner in the core is shown at X and in 
 this case must be made of the length shown at Y, Fig. 3. The frame 
 used upon the bottom plate shown in ¥ig. 2 is of the opposite hand 
 in respect to the runner X only, and this runner has to be of a length 
 equal to Z, Fig. 2. A pair of the half cores which have passed 
 through the operation of ramming and drying are shown ready for 
 jjasting together in Fig. 5. 
 
 Fig. 2. Bottom Plate for ForminR one Core 
 
 The arrangement for cores as they would appear when stacked 
 and bolted together ready for casting is shown in Fig. 6. This simply 
 consists of a cast iron bottom plate provided with lugs to receive 
 holding down bolts and of sufficient length and width to receive four 
 complete cores. The cores are stacked up to the desired height, say 
 four feet in the case illustrated. The holding down bolts are set in 
 position, the two top plates applied across the cores and the whole 
 securely bolted together. To prevent the cores from separating 
 lengthwise, two clamps can be dropped over the top plates and wedged 
 up as shown. The runner is next placed in position, when the mold 
 is ready for the metal. 
 
MULTIPLE CORE MOLDING 
 
 3-II 
 
 Fig. 3. Bottom Plate for the other Core 
 
 One point that is worthy of notice in this connection is that this 
 process works remarkably well for steel, on account of the fact that 
 steel solidifies so quickly that it has very little tendency to work into 
 the joints between the cores and before the upper part of the mold 
 is filled all of the runners in the lower part have chilled so that part 
 of the mold is never subjected to the fluid pressure of a column of 
 molten steel equal to the height of the pile of cores. If this method 
 were used for gray iron castings it might be found necessary to place 
 curbing about the molds and ram in sand between the curbing and 
 the cores. 
 
 Making the Core Boxes 
 
 As the frame which forms the sides and ends of the cores as 
 shown in Fig. 4 is a very simple casting which is molded from a 
 wooden pattern, its production will not be taken up in detail, but we 
 
 (T 
 
 p^ — 
 
 Itunner JC 
 
 
 
 i^ 
 
 Fig. 4. Side Plates for Core Box 
 
 Fig. 5. Section of a Pair of Cores 
 
4-II MOLDIXG IN CORES 
 
 will discuss only the method required for the production of the plaster 
 of paris bottom plate patterns from the original wood pattern. The 
 wooden pattern is shown at the right of Fig. 7, while to the left is 
 shown the board upon which the pattern is placed for making the 
 first cast. To allow the pattern to lie flat on the board a depression A 
 is cut out to receive the lower shoulder. The pattern is then placed 
 
 Cast Tron.£late 
 
 M" 
 
 Fig. 6. Stack of Cores ready for Casting 
 
 Fig. 7. Wooden Pattern and Pattern Board 
 
 in position and the material B, C and D placed about it to bring the 
 parting in the right position and this is secured to the board by screws 
 from the under side, as the pattern is also. The whole is then given 
 
 ^<MUline of Frame 
 
 Outline of Frame 
 
 Fig. 8. Board with Pattern in Place 
 
 a heavy coat of shellac. Fig. 8 shows the board with the pattern in 
 place ready for making the first plaster cast. 
 
 A light wooden frame or box, the inside dimensions of which 
 correspond to the length and width of the desired core as shown in 
 
MULTIPLE CORE MOLDING 
 
 5-II 
 
 Fig. 5, and with a depth of about 3>4 inches, is nailed together and 
 secured upon the board, as indicated by the dotted Hnes. The board 
 and pattern are then well oiled or greased, after which attention is 
 given to the mixing of the plaster. 
 
 To insure good results, very fine, or as it is sometimes called,, 
 dental plaster, should be used. Care should be taken to see that all 
 lumps are broken up, and to accomplish this it is a good plan to run 
 the plaster through an ordinary flour sieve before mixing. The 
 plaster should always be kept inclosed and in a dry place. Two 
 
 Fig. 10. Second Cast 
 made from the First 
 
 Fig. 9. First Plaster 
 Cast 
 
 Fig. 12. Plaster Pat- 
 tern made from Cast 
 Fig. 9 
 
 Fig. 11. Plaster Pat- 
 tern made from Cast 
 Fig. 10 
 
 persons should work together when doing the mixing, so that it may 
 be accomplished quickly. First, fill the can in which the plaster is to 
 be mixed with the desired amount of water and introduce a small 
 quantity of plaster. The plaster should be introduced by one person, 
 while the other stirs the mixture. If it thickens too fast, more water 
 should be added. It should be mixed to the consistency of heavy 
 cream. 
 
 When pouring care should be taken to see that work sets level 
 and the plaster should be poured as quickly as possible over the entire 
 surface. If the plaster has been mixed properly the screws can be 
 taken out and the frame and bottom board removed in about 30 min- 
 utes. Should the pattern or material forming the parting stick in the 
 least, it can generally be loosened by rapping it lightly. 
 
 Blow holes are apt to appear in the plaster and when encountered 
 they can be filled up with either plaster or wax. 
 
 If this operation has been successfully accomplished the plaster 
 cast will appear as shown in Fig. 9. Fig. 10 shows the second cast 
 
6-II 
 
 MOLDING IX CORES 
 
 which has been obtained from the first cast shown in Fig. 9 with the 
 aid of the wood pattern and a Hght frame about 4^^ inches in depth. 
 In carrying out this work the face of the first cast is shellacked and 
 then covered with a good application of oil or grease. The pattern 
 is then ])laccd upon the first cast in the depression left vacant by it, 
 the cast is placed upon the level board, the frame set over it, and the 
 mixing of plaster and pouring proceeded with, as in the former case. 
 
 Sectio/i K'K Section Z-L 
 
 Figs. 13-14. Sections of Casts ready to receive the Plaster 
 
 It is next necessary to cast the two plaster patterns, as shown 
 in Figs. 11 and 12. The plaster pattern shown in Fig. 11 is produced 
 from the plaster cast shown in Fig. 10, while the plaster pattern shown 
 in Fig. 12 is produced from the plaster cast shown in Fig. 9. 
 
 As the plaster casts now made are of the same length and width 
 as the desired cores, provision must be made for the additional width 
 or projecting edge E, Figs. 11 and 12. This projecting edge around 
 the four sides is intended to receive the flange of the frame, as shown 
 ir Fig. 4. This is accomplished by placing the material F, Figs. 13 
 and 14, which in thickness is equal to the width of the flange, on the 
 frame shown in Fig. 4, around the four sides of the plaster cast. The 
 entire arrangement is then surrounded with a light frame G, Figs. 13 
 and 14. Cross sections on the lines KK and LL of the two plaster 
 casts shown in Figs. 9 and 10, as they would appear arranged ready 
 to receive the plaster, are shown in Figs. 13 and 14. 
 
 As in the previous case, to prevent the plaster sticking, grease 
 or heavy oil should be used freely over the entire surface. 
 
 At the completion of the casting of the plaster patterns, they are 
 removed from their casts or forms and a coat of shellac applied to 
 the face. They are then backed out to give the required metal thick- 
 ness. A good portion of this surplus plaster can be avoided by placing 
 blocks H and I upon the bottom board as shown in the cross sections, 
 Figs. 13 and 14. The patterns are finished with two coats of shellac. 
 The gate J, Figs. 2 and 3, is next worked out of a piece of wood and 
 attached in the correct position, being secured with shellac. The pat- 
 terns are then sent to the iron foundry. When the castings come 
 back from the foundry they are cleaned up and finished in the usual 
 manner, the plates being doweled or pinned to the frames shown in 
 Fig. 4. 
 
LARGE WORK IN CORES 7-II 
 
 CHAPTER II 
 
 STACKING CORES FOR LARGE WORK 
 
 When it is necessary to cast a considerable number of large steel 
 castings from special heat which requires practically all of the metal 
 from one charge of an open-hearth furnace, the question of floor space 
 for the large molds is often an important one and the foundryman 
 frequently finds himself in a quandary as to the best method of getting 
 out of the difficulty. One method of solving this problem is shown 
 in this chapter and consists in simply stacking or piling upon one 
 another a series of cores which form the molds for the rings or pieces to 
 be cast. Of course, it is necessary to provide a proper arrangement of 
 gates so that the rings may be cast from the same runner, and also 
 to provide risers. While this method of molding will not under ordi- 
 nary circumstances be found the cheapest on account of the expense 
 
 10 Cored Holes Eqvalhi Spacerl 
 
 Inverted Plan 
 
 Fig. 15. Section of Ring Casting 
 
 of making the cores, etc., it will be found that the extra expense in- 
 curred will not condemn the method, owing to the saving in floor 
 space, etc. The rings illustrated are about twelve feet in diameter and 
 have a cross section as shown in Fig. 15. 
 
 A cross section of one of the bottom cores, together with the box 
 in which they were formed, is shown in Fig. 16, the core box being 
 shown in the plan and cross section. In like manner in Fig. 17 is 
 shown a cross section of one of the top cores together with the plan 
 and cross section of the core box in which it was formed. It will be 
 observed that a male and female joint is formed upon the two cores, 
 this being necessary to locate them in position one upon the other. 
 
 Setting the Cores 
 
 In constructing the mold a hole is dug in the floor to the required 
 depth. The spindle with the sweep attached is next located in its proper 
 
8-II 
 
 MOLDIXG IX CORES 
 
 position and a level bed struck off. The sweep is then raised to the 
 required height and the lower half of the first series of cores placed in 
 position. The proper diameter of the ring is maintained by setting 
 the cores to the gauge A which is attached to the sweep, as shown in 
 Fig. 18. 
 
 At the right in Fig. 18 is shown the setting of one of the bottom 
 cores, while at the left of the spindle is illustrated the operation of 
 sweeping off the bed to receive the cores. 
 
 
 mm' J, 
 
 
 ^Trry 
 
 
 M 
 
 
 \ Section of 
 
 
 ^i 
 
 % 
 
 
 \ Bottom Core 
 
 4»^u(( Slot 
 
 ^^ Corea 
 
 
 mil 
 
 B 
 
 -' 
 
 Sec 
 
 tion B- 
 
 
 /I ( T) Section of 
 Top Core 
 
 Fig. 16. Section of Bottom Core and Box 
 
 Fig. 17. Section of Top Core and Bo.x 
 
 The upper series of cover cores is next placed in position, being 
 guided by the male and female joints. A light thickness of sand is 
 next applied over the upper surface, the sweep is raised up and the 
 sand applied struck off level to receive the bottom cores of the second 
 set. The second set of cores are located with the aid of the gauge A 
 as in the first case. In this way the work is proceeded with until all 
 three of the series of cores forming the complete mold have been 
 placed in the proper position. 
 
 The runner is centrally located and each ring receives metal from 
 four gates placed at right angles to one another, as shown in Vig. 19, 
 which illustrates two half sections of the mold. The section at the 
 right being taken through the gates illustrating the manner of gating, 
 while the section at the left is taken through the risers and illustrates 
 the manner of attaching the same. It will be noticed that the risers 
 are placed on the outer diameter of the rings. 
 
 After the three scries of cores are set in position the molder has 
 to turn his attention to the placing of the runner and gate cores, the 
 arranging of the risers. This work being done during the backing up 
 of the mold with sand, as shown in the cross section of the completed 
 mold. 
 
 Sand is first rammed inside and outside of the cores to the height 
 of the gate openings on the inner diameter of the cores and the risers' 
 openings on the outer diameter of the first series of cores. 
 
LARGE WORK IN CORES 
 
 9-II 
 
 The runner and gate cores are shown in detail in the upper part 
 of Fig. 19 and also in position in the lower part of the figure. After 
 the first set of cores for the gates are placed in position the first one 
 of the block cores for the runner is placed in the center and the ram- 
 ming in of the sand backing proceeded with until the openings in the 
 
 Fig. 18. Spindle Rigged for Setting Cores 
 
 second series of cores are reached when the gate cores and next block 
 for the runner core are set as in the first case. When the backing of 
 sand reaches the top of the upper series of cores a level bed is struck 
 oflf to receive the holding down plates. 
 
 The risers are formed by the use of the riser block shown in the 
 upper left hand corner of Fig. 19. The runner and risers are next 
 
 Riser Block 
 
 Fig. 19. Section of Mold 
 
 carried up to the desired height and the weighting down of the cores 
 attended to. It will be observed that the riser for the lower ring is 
 not carried to the same height as the others on account of the fact 
 that it is not necessary to do so. The riser for the first ring is ter- 
 
lO-II MOLDIXG IX CORES 
 
 ininated at the surface of the mold as indicated by the words "bottom 
 mold." The riser for the second ring is terminated at the dotted line 
 designated "middle mold," while the riser for the upper mold is carried 
 up to the same height as the gate. When the metal in the first riser 
 has almost reached the surface of the mold the riser is covered with a 
 plate and weighted down. In like manner when the metal reaches the 
 top of the second riser it is covered and weighted. 
 
ROUND FLASKS IN CORES 
 CHAPTER III 
 
 11-11 
 
 CASTING ROUND FLASKS IN CORES 
 
 The accompanying illustrations show one method of casting round 
 flasks of large diameter in cores which has given very satisfactory 
 results, and a saving in pattern expense, as well as in the floor space 
 required for pattern storage. A plan and cross section of a portion 
 of the required flask is shown in Fig. 20. It will be noted that there 
 are two lines of cored bolt holes about the flask and a sand strip on 
 the inside of the top and bottom. In most cases, four trunnions are 
 cast on each flask, one of these being shown in Fig. 20. 
 
 GATE AND RUNNER 
 
 
 Fig. 21 
 
 Fig. 20. Plan and Section of a portion of 
 the Pattern 
 
 Fig. 21. Cores in Position 
 
 Fig. 22. Segment for Setting Cores 
 
 A cross section through one side of the assembled cores is shown 
 in Fig. 21, illustrating the manner in which the cores are placed to- 
 gether. In making up the mold a hole is dug in the floor to a depth 
 
12-11 
 
 MOLDING IX CORES 
 
 equal to the height of the cores and with the aid of straight-edges a 
 level bed is struck off. 
 
 With the segment attached to and revolved about the stake as 
 shown in Fig. 22 an offset shown at A, Fig. 21, is rammed up to assist 
 in setting the cores. 
 
 The number of separate pieces or cores is governed by the diameter 
 of the flask. The circle formed by the offset is divided by four equi- 
 distant lines, and the centers of the four cores containing the trun- 
 nions are set to these lines. 
 
 Fig. 23. Core Box for Outer Cores 
 Fig. 24. Core Box for Trunnion 
 Fig. 25. Core Box for Inside Cores 
 
 Fig. 25 
 
 At the completion of the setting of the remaining cores, sand is 
 banked and firmly rammed around the inside cores, as well as in the 
 space between the outside of the cores and the wall of the hole or pit. 
 To avoid filling the entire space inside the cores with sand, a flask of 
 convenient diameter and height can be placed within the inclosure 
 formed by the cores and the space between the flask and the cores 
 rammed firmly with sand. 
 
 The core box used in forming the outer cores is shown in Fig. 23. 
 The trunnion and rib portions are loose from the box, allowing these 
 
ROUND FLASKS IN CORES 13-11 
 
 parts to be removed when the plain cores are being made. The bolt 
 holes are spaced off accurately, and taper prints are set to receive the 
 separate cores for these holes. By giving the core prints ample taper, 
 they can be rigidly attached to the box. A covering core is used in 
 connection with this box to form part of the trunnion, this portion of 
 the box being parted as shown with the core print above and extendnig 
 to the top of the box. 
 
 When the print has been withdrawn the core made in the core box 
 shown in Fig. 24 is placed in this impression so as to close the opening 
 and form the flange or outer end of the trunnion. 
 
 The core box used in forming cores for the inside of the mold is 
 shown in Fig. 25, and it will be noticed that loose wedge pieces are 
 used to form the radial ends of the cores. To simplify the construc- 
 tion of the box and facilitate the drying of the core, the open side of 
 the box is made flat in place of conforming to the diameter of the mold. 
 Gates are filed in the tops of these cores at different points, and runners 
 built up as shown in Fig. 21. 
 
14-11 
 
 MOLDING IN CORES 
 CHAPTER IV 
 
 MOLDING A THREE-WAY COCK 
 
 A three-way cock or plug valve of the design shown in Fig. 26 
 is in many ways a difficult casting to mold. If molded in green sand 
 it would require a three-part flask in addition to the cores. 
 
 In most cases this piece can be molded in cores more quickly 
 and cheaper than in any other way. 
 
 In Fig. 26 the central view shows a plan of the cock, the left hand 
 figure a side view and the right hand figure a section on the line X, X. 
 
 Section X-X 
 
 Fig. 26. Three-way Cock 
 
 This design of valve is also sometimes made with an open bottom 
 A, which is subsequently covered with a plate secured to the cock. 
 
 To a patternmaker or molder the various disadvantages and diffi- 
 culties in connection with this job will be readily appreciated, but 
 without stopping to discuss these we will proceed to describe one 
 method that has proven very successful in many cases. 
 
 The cores for the mold are shown in Fig. 27. The upper view 
 is a horizontal section taken on the line U, U, while the lower view 
 shows a vertical section taken on the line Y, Y. The outer part con- 
 sists of three cores B, C and D, which are joined on radial lines at 
 E, F and G. 
 
 The center core H and the core for the passage on the line G 
 are made in one piece, while the cores for the passages E and F are 
 made separate as shown at I and J. 
 
 When assembling the mold the cores C and D are placed together 
 with the center passage core H in place with its projection for the 
 passage core between the cores C and D. This holds the core H in 
 place and locates it correctly. 
 
 Before the core B is set the cores I and J must be set into the 
 center core H and held in place until the core B is located. To assist 
 in holding the cores I and J in place they are made long enough so 
 
A THREE-WAY COCK 
 
 15-11 
 
 that their ends project as shown at K. These projected ends may be 
 held or blocked up, while setting the core B. 
 
 When the parts have been assembled a flask is placed around the 
 group and a backing of sand rammed in. 
 
 The core boxes are made as shown in Figs. 28, 29 and 30. The 
 box for making the large cores B, C and D is shown in Fig. 28, the 
 upper view being a plan and the lower view a section on the lines 
 Z, Z. The checks L, L are made loose in the box as are also the 
 diagonal pieces M, M, which carry the patterns P, P. When making 
 a core the box is rammed full of sand, the blocks L taken out and 
 the depressions left filled in with green sand. The box is then rolled 
 
 Fig. 28. Core Box for Body 
 
 Section 1'- 1' 
 
 Fifif. 27. Cores for the Mold for a Three-way Cock 
 
 over and the main gate drawn out through the side of the box (of 
 course the gate is only required in one of the three cores). After the 
 gate has been drawn the frame is removed and the blocks M, M 
 carrying the patterns P, P drawn. This leaves the gate N exposed 
 to be drawn. 
 
 In order to make the center and passage core H entire as shown 
 in the assembled mold, two half core boxes, one of which is shown in 
 Fig. 29, will be required. The core print in the bottom of the center 
 
1&-I1 
 
 MOLDING IN CORES 
 
 portion of the box is left loose to be drawn from the core after the 
 latter has been turned over onto the core plate. 
 
 F 
 Fig. 60 
 
 Fig, 29. Box for Central Core with one Branch 
 Fig. 30. Box for Branch Cores 
 
 Two other half boxes, shown in Fig. 30, are necessary for making 
 the cores I and J shown in Fig. 27. The reason both half boxes are 
 required for this purpose is on account of the taper of the center 
 core H. 
 
COVERING CORES 17-11 
 
 CHAPTER V 
 
 THE USE OF COVERING CORES 
 
 There are a very great number of ways in which covering cores 
 can be used, but the accompanying illustrations cover the principal 
 uses of this class of cores. 
 
 Covering cores are also frequently called slab cores, and can often 
 be set without the aid of a core print. 
 
 The use of the covering core frequently saves a three-part flask, 
 or the adoption of a more intricate cored mold and expensive patterns. 
 
 ^ Core Side ***'''.C^O J'in.34 
 
 Fig. 31. Covering- Core for Casing 
 Fig. 32. Stuffing Box Pattern 
 
 Fig. 33. Pattern and Mold for a Double Bearing 
 Fig. 34. Mold for a Shrouded Gear 
 
 In some cases, especially in a deep setting, the covering core may be 
 objected to by some foundrymen, on account of the difficulty of remov- 
 ing any sand which may fall into the mold during the drawing of the 
 pattern. When the covering core is used in the cope, this objectionable 
 feature is done away with, as the core may be placed in the depression 
 left by the core print previous to or after the closing of the mold. 
 When the core is used in this way, of course it is inserted through the 
 cope and weighted or wedged down. 
 
 The application of a covering core to a mold for a casing or hood 
 is shown in Fig. 31. In this casting there is a very light metal thick- 
 ness and the advantage of the suspended core in regard to venting and 
 also setting, in the production of a sound casting will be readily seen. 
 
 The molding of such a piece as this with the ordinary dry sand 
 core would usually make it necessary to cast or mold the piece in a 
 reverse position and this would not, as a rule, give good results. When 
 a metal pattern is used which leaves its own core it is possible to mold 
 the bowl in a reverse position successfully. 
 
18-11 
 
 MOLDING IN CORES 
 
 A cylinder head and stuffing box pattern are shown in Fig. 32, 
 together with a core print for the covering core attached. This arrange- 
 ment gives a very simple pattern and mold. The core print is drawn, 
 together with a part of the pattern A, during the ramming up of the 
 mold, and the slab core interposed in place of the core print. The 
 
 Fig. 35. Covering Cores with Curved Ends 
 
 ramming of the mold is then completed by the ordinary method. This 
 operation is described and illustrated more fully in the next example. 
 
 The covering core method as applied to a double bearing is illus- 
 trated in Fig. 2>2>. At the left is shown the end view of the bracket 
 portion of the pattern, illustrating the general construction of the 
 bracket and showing the parting line ABC. At the right is shown 
 a longitudinal section of the partially completed mold with the cover- 
 ing core in place. 
 
 In making the mold the pattern is placed upon the board and 
 rammed up to the top of the core print in the ordinary manner. The 
 core print, with a portion of the bearing above the line A B C, is next 
 withdrawn from the sand and the covering core placed in the depres- 
 sion left by the core print. The balance of the flask is now rammed 
 up, struck off and rolled over in the ordinary manner. The cope is 
 then placed in position, the ramming completed, and the balance of 
 pattern drawn as usual. 
 
 The covering core as applied to a shrouded gear is shown in Fig. 
 34. The illustrations show the pattern rammed up with the core in 
 place and the flask rolled over ready for placing the cope in position. 
 
 Many circular pieces of work in the foundry can be covered with 
 slab cores to save the ramming up of the cope. This method is shown 
 in Fig. 35. Usually the ends of the cores radiate to the center. When 
 this is the case unless they are made to the proper diameter the ends 
 
COVERING CORES 19-11 
 
 will not fit together without filing and fitting of the cores. As these 
 cores are frequently kept in stock, they are a source of much trouble 
 to the molder. This trouble can be readily done away with by making 
 the end of one core convex and the corresponding one concave, as 
 shown in Fig. 35, where the curved line ABC represents the junction 
 between the adjacent cores. By this arrangement the ends of the 
 cores can be kept together while they are adjusted for almost any 
 radius of mold. 
 
20-11 
 
 MOLDING IN CORES 
 CHAPTER VI 
 
 T SLOT AND NAME PLATE CORES 
 
 The use of chaplcts for holding down the cores in floor plates, 
 etc., is generally a source of considerable trouble, but this difficulty 
 may be done away with by constructing the cores as shown in Fig. 36. 
 At the left is shown the pattern with a core print attached and the 
 outline of the core shown by dotted lines. To the right is shown a 
 cross section of the mold, with the core in place. 
 
 Core Print Core 
 
 Fig. 36. T Slot Cores 
 
 It will be noticed that the core print is wider than the head of the 
 T slot and hence when a core of this section is set into the depression 
 made by the core print and the metal flows into the mold, there will 
 be more area exposed to the metal along the width A than along the 
 width B, in other wofds, the surfaces D are wider than the surfaces C, 
 
 m 
 
 Print portion 
 of Cot 
 
 Scvtion of ?Iol<l 
 
 Fig. 37. T Plot Core 
 
 Section of Core 
 
 hence the metal which exerts a lifting force along the overhanging 
 portions C will be more than balanced by the metal bearing down on 
 the portion D. With cores made and set in this manner, no chaplets 
 are necessary. 
 
 These cores are even better illustrated in Fig. 37. This illustration 
 shows a form of core which is used by the author with good results. 
 At the left of the fisrure is shown a section of the mold with a core in 
 
NAME PLATE CORES 
 
 21-ir 
 
 place, while at the right there is a detailed drawing of the cross section 
 of the core. 
 
 The lettering is the same as that in Fig. 36. Some persons have 
 claimed that cores of this kind would not stay down if no nails were 
 used. The author has watched every step of making and pouring the 
 
 -^-7+^ 
 
 G 
 
 FIG. 39 
 
 Fig. 38. Core Print for Name Plate 
 Fig. 39. Core Print Box for Name Plate 
 
 mold many times and knows that they will work if there is no opening 
 under the base of the core into which the metal can flow. If metal 
 flowed under the base of the core it would be lifted. But any good 
 molder will see that the sand is slicked up to each side of the base of 
 the core. 
 
 Figs. 38 and 39 show a method employed in placing name plates 
 
22-11 MOLDING IS CORES 
 
 upon engine beds, etc., and one which insures their non-removal except 
 by chipping. The method consists in the use of a slab core of any form 
 made from a core box upon the bottom of which is placed the desired 
 lettering. 
 
 Fig. 38 shows the core print, in this case of an elliptical form, and 
 secured to the pattern by two loose dowels of different diameter as 
 shown, in order to avoid placing the core print in the reverse position. 
 A marker "B" is also required upon the print and in the core box, to 
 insure placing the core in its correct position in the depression left 
 vacant by the core print. 
 
 Fig. 39 shows the general arrangement of core box which is 
 parted on the lines "C C" and "D D." 
 
 The frame or print portion "E" having been gotten out to conform 
 to the core print shown in Fig. 38, it is placed upon the bottom board 
 "F" and secured with dowels, and its elliptical outline is scribed 
 thereon. The surface inclosed by this outline is now backed out or 
 depressed to the required depth "G" (which is usually the thickness 
 of metal letter used) and the metal lettering is attached in the ordinary 
 manner. 
 
A SMALL STEEL CASTING 23-11 
 
 CHAPTER VII 
 
 MOLDING IN CORES 
 
 In many cases, and especially in the case of steel castings usually, 
 better results can be obtained from a dry sand mold, and frequently 
 this can be obtained more easily and economically by making suitable 
 core boxes and forming the mold of cores. 
 
 A Small Steel Casting 
 
 Fig. 40 shows a required casting 10 inches in length which would 
 be rather difficult to mold from an ordinary pattern withou*^ an exceed- 
 ingly complicated mold. Fig. 41 shows a plan of the core box and a 
 section of the pattern on the line A-B, Fig. 40. 
 
 Fig. 41. Plan of Core Box 
 
 Fig. 40. Casting to be made in Cores 
 
 Fig. 42 shows the manner in which different parts of the pattern 
 are set together. The pattern is made in five parts, as indicated by the 
 letters V, W, X, Y and Z. In Fig. 42 the pattern is shown half in 
 section and half in elevation, so as to show the manner of parting the 
 different pieces of the pattern. The half section is taken on the line 
 
24-11 
 
 MOLDING IN CORES 
 
 E-F, Fig. 41. It will be noticed that the pattern is set in to the bottom 
 board holding the parts in position. 
 
 The core box is made deep enough to allow a sufficient amount of 
 sand above the pattern, and the core print U is placed upon the pattern 
 as shown in Fig. 42. The height of the core print is equal to the 
 amount of sand allowed above the pattern and the diameter of the 
 small end should be large enough to allow the part V of the pattern to 
 be drawn with the print. 
 
 In making a core the pattern is placed in the core box, rammed up 
 and struck off. The core print U and portion of the pattern V are then 
 drawn, after which the core box is rolled over and the parts W, X, Y 
 and Z drawn from the other side. 
 
 Figr. 42. Arrangement of Pattern 
 
 SEGTION A-B 
 Fig, 43. Section of Pattern 
 
 Fig. 43 shows sections of the pattern on the lines A-B and C-D. 
 
 A block the form of the core with a depression corresponding to 
 the core print U, not shown, is used as a pattern to make a mold to 
 receive the core, the mold being gated through the portion of the cope 
 fitting the space U. 
 
 When a great number of castings are required a box can be 
 made large enough to receive a number of these cores, and rammed up 
 with depressions in the drag. A runner can be rammed up in the 
 center one in place of one of the patterns and the surrounding ones 
 gated from this. This manner of coring will be found very convenient 
 in small steel castings where a dry sand mold is desired. 
 
PROPELLER WHEEL IN CORES 
 A Small Propeller Wheel 
 
 25-11 
 
 Small propeller wheels may also be molded in cores, either dry 
 sand or green sand, by using a core box of the form shown in Figs. 
 44 and 45. 
 
 One advantage of this method is that it assures the fact that the 
 blades are as nearly alike as it is possible to make them, which is im- 
 portant. Usually in molding a pattern of this description a follow 
 board is used, while that part of the core box containing the back 
 of the blade is rammed up. The face of the follow board can be de- 
 veloped and built as a propeller blade. As a blade contains but a small 
 portion o/ the area of the surface of the box, it is not necessary to 
 make a follow board the full dimensions of the size of the box, but just 
 wide enough to form a joint all around the blade. The remaining por- 
 tion of the surface can be cut away to any convenient angle, as shown 
 Fie. 45. 
 
 Figr. 4b. Section of Core Bo.x for Propeller Wheel 
 
 Fig. 44. Plan of Core Box for Propeller 
 
 By building the follow board first, so that its face represents a 
 portion of the face of the blade it can be used in building and laying off 
 the pattern, the pattern being built by gluing strips together, and work- 
 ing off back to the proper form. 
 
 If the pattern is made first, the follow board can be made of 
 plaster of paris, the pattern being used to give it the proper shape. 
 Plaster being used for very small wheels only. 
 
 In molding patterns of this description by this method, iron skel- 
 etons or core irons wnth suitable lifters must be provided for both parts 
 of the mold for lifting out the core. 
 
 When making a mold, the top part of the core box containing 
 the back of the blade is rammed up first with a core iron or skeleton 
 properly placed, the core box is then rolled over, the follow board 
 removed, the parting prepared and the balance of the core box rammed 
 up with the core iron or skeleton in place. After the ramming is com- 
 
26-11 
 
 MOLDIXC IN CORES 
 
 pleted, the core box is removed, the cope part of the mold Hfted off 
 and held suspended while the pattern is withdrawn and the mold fin- 
 ished. A level bed is then prepared and the drag part of the core is 
 placed upon it and the cope part on top of the drag portion. These 
 operations are repeated for each of the succeeding blades thus forming 
 a complete circle. 
 
 Of course in the case of dry sand cores they must be baked before 
 they are placed upon the bed. 
 
 After the cores are placed in position upon the bed an open flask 
 or box or a metal curbing is placed around them and the space between 
 the cores and the box or curbing rammed with sand to form a backing. 
 The cores must also be weighted down. 
 
 A Large and Crooked Steel Casting 
 
 A large steel casting weighing 8,000 pounds is shown in Fig. 46. 
 This is a cutter head used on a large centrifugal dredge. 
 
 Fig. 46. Forge Steel Casting 
 
 Fig. 47. Plan of Core Box 
 
 From the form it will be seen that this would be a rather difficult 
 piece to i)roduce in an ordinary green sand or dry sand mold. But by 
 molding in cores in a manner similar to that used for small propeller 
 wheels, the work was accomplished with ease. 
 
 Fig. 47 shows a top view of the core box, with the pattern for one 
 of the five arms in place. Fig. 48 shows the core box with the front 
 removed and shown at the left. The pattern is shown in place in the 
 portion of box on the right. 
 
 In making one section of this mold in the core box, that portion 
 of the core which contained the back of the blade was rammed first, 
 the core iron or lifting plate being ])laced near the bottom of the box. 
 
A STBEL CUTTER HEAD 
 
 27-11 
 
 A parting was made along the edge of the blade as the ramming pro- 
 gressed. This parting was then covered with parting sand, a lifting 
 iron introduced for the upper portion of the core and the upper portion 
 rammed. The front of the box was then removed and the sides 
 drawn back, leaving the core free. The top or cope part was then 
 lifted off and held suspended while the pattern was drawn and the 
 mold finished. It was then placed back in position and the whole 
 
 Fig. 48- Elevation of Core Box with Front removed Fig. 40. Block or Model of Pattern 
 
 core shoved into the oven to be dried. For convenience the core was 
 made upon a car so that it did not have to be removed from the 
 car to introduce it into the oven. 
 
 After the five sections were completed, a pit was dug, a level bed 
 swept up, the sections placed together, provision made for suitable 
 gating and for sinking heads. The whole was then backed up with 
 sand thoroughly rammed. 
 
 Fig, 50. Plan of Supports on Building Board 
 
 The pattern for this job was made as follows : Owing to the 
 angular form of the blade it was impossible to lay it out from the 
 drawing in a reliable manner and hence a block or model was turned 
 to scale, as shown in Fig. 49. The diameter and form of this block 
 corresponded with that of the cutting edge except that it was made 
 
28-11 
 
 MOLDING IN CORES 
 
 to a smaller scale. The outline of the cutting edge was then laid off 
 on this block and the material cut away so as to give the sections A, 
 B, C, D and E. The whole surface between these sections was cut 
 away to represent the under side of the blade. The width of these 
 sections was laid off and these points connected with a flexible rule or 
 strip and this line was sawed perpendicular to the base, giving the inner 
 outline of the blade. This outline was then transferred full size to the 
 building board and perpendicular supports erected as shown in Fig. 
 50. these supports conforming with the angle of the blade at the 
 points A, B, C, D and E, Fig. 49. A half hub was made and secured 
 in its correct position. The portions of the hub outside of the lines 
 A-B and A-C Fig. 50, were afterwards cut away to fit the core box. 
 The pattern was built by fitting pieces over the supports as shown 
 by the parallel lines in Fig. 50. These being glued together and to 
 the hub, and the back worked off. The pattern was subsequently 
 parted on the lines A-B and A-C and the portions of the pattern which 
 fell outside of these lines were secured to opposite sides of the core 
 box, as shown in Figs. 47 and 48. 
 
 Molding Rope Sheaves 
 
 A method of molding rope sheaves having wrought iron arms 
 which are staggered in the hub is illustrated in Fig. 51, the left hand 
 portion of the figure showing a section of the wheel and the right hand 
 portion the method of making the mold. 
 
 Fig. 51, Half Section of Rope Sheave and Half Section of Mold 
 
 The core boxes for making the cores A and B for the upper and 
 lower portions of the hub and the middle portions C and D are shown 
 in Figs. 52 and 53 the boxes being shown in plan in the lower portion 
 of the figures, and in section in the upper portion. These cores form 
 the mold for the outside of the hub. An ordinary circular core formed 
 in a regular core box is used for the bore of the hub. 
 
 In Figs. 54 and 55 are shown the core boxes for forming top and 
 bottom rim cores E and F and the jjroove core C. 
 
MOLDING ROPE SHEAVES 
 
 29-11 
 
 At A-B, Fig. 54, are shown two core prints used in the rim core 
 box as shown in the section on the line Y-Z for forming the openings 
 for the introduction of the wrought iron rods. It is necessary to 
 change these prints for the top and bottom cores E and F, owing to 
 the fact that the rods enter the rim at an angle and that this angle 
 alternates with each succeeding spoke. 
 
 Fig. 53 Fig. 52 
 
 Fig, 52. Core Box for outside Section of Hud 
 Fig. 53. Core Box for inside Section of Hub 
 Fig. 54. Rim Core Box 
 Fig. 55. Groove Core Box 
 
 Fig. 54 
 
 Fig. 55 
 
 In making this kind of a mold, a level bed is struck up and the 
 block or print bedded in to receive and set the hub core. The height 
 of this is equal to H, as shown in Fig. 51. To a pin or spindle in the 
 center a sweep is attached as shown in Fig. 56. 
 
 This sweep is used for forming the bed which is to receive the 
 rim cores E and the groove cores G. After this has been accomplished 
 the lower section of the hub core A and the rim cores E are set, then 
 
 P 
 
 o 
 
 .o \ 
 
 Fig. 56. Sweep in place for Sweeping Bearings 
 
 Fig. 58. Elevation of Forge Gear Bolting Face 
 
 the rods which enter the core A are placed in position, the groove core 
 G is set and the middle section hub cores C and D. 
 
 Then the rods which enter the upper portion of the core are placed 
 in position and the upper portion of the hub core B and the rim cores 
 F placed in position. 
 
 The hub cores C and D should be carefully pasted together, so 
 that the upper and lower prints to receive the rods will come exactly 
 
30-11 
 
 MOLDIXG I.y CORES 
 
 between each other. Tlie bore core is set before the top core B is 
 placed in position. 
 
 After all the cores are in position, the mold is rammed up with 
 green sand and weighted. In pouring a wheel of this description the 
 rim is usually poured and allowed to cool before the hub is poured, 
 as this lessens the strain caused by contraction and produces a sounder 
 and better wheel. 
 
 Molding Large Gear Wheels 
 
 One method of molding a large gear in cores is shown in Figs. 
 57 and 58. This method was applied to a cast steel split gear 15 
 feet, 6 inches in diameter, 4 inch circular pitch, 144 teeth, and 16^ 
 inch face, with a T section flange cast on one siae and joined to arms 
 about midway between the hub and the rim. The entire gear weighed 
 26.000 pounds. A drawing of a portion of the gear is shown in Fig. 
 57 a section of the rim, of the T flange and the arm being shown. The 
 
 
 
 
 
 SLAB CORE 
 
 ^' 
 
 t.\v:-.7^;::;;\:-:A.Vl--SLAB CORE kv"'.'.v^£-- 
 
 Wfi 
 
 
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 J^:;,-^^^^^^^^ 
 
 
 
 
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 F?/';-'- 
 
 
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 ^V;::v;^ 
 
 
 
 WM^ 
 
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 ■ • :.:•■- ■■.;.■ ■ .-: i ; :-.■■'. ^^ ■ ■ ■•• , • - . , 
 
 
 ' 
 
 
 
 
 
 
 
 Fig. 59. Section of Mold 
 
 dotted lines in Fig. 57 show the arrangement of the different cores 
 which were used in forming the mold. In Fig. 58 a half elevation 
 of the bolting face of the gear is given, showing the location of the 
 bolt holes, which were cored, the construction of the hub, etc. 
 
 A section of the mold through the center of one of the arms is 
 shown in Fig. 59. It will be noticed that a slab core is used for cov- 
 ering the joint at the hub, and also under the portion of the T flange 
 opposite the arm. 
 
 In making the core for the arm it was rammed level with the T 
 flange, the face portion then drawn and the slab core placed over it, 
 after which the box was rammed full. 
 
 The arm core box was used for the upper and lower halves of the 
 arm cores, the flange portion of the pattern being removed for the 
 upper half of the core. The same box was also used for the half arm 
 cores on the bolting line, a half arm with pads and core prints being 
 
A LARGE GEAR 
 
 31-11 
 
 used in the box as shown in Fig. 60. In this case part of the box 
 was stopped off longitudinally by dropping in a board. 
 
 The manner in which the cores for the portion of the T section 
 flange between the arms were joined together is shown in Fig. 61. 
 
 In beginning the mold a pit was dug as deep as the cores were 
 
 T- 
 
 Fig. 62. Spindle and Gauge Stick 
 Fig. 63. Gauge Sticic for Teeth 
 
 Fig. 57. Plan of Large Gear 
 
 high, and a level bed struck off. With the aid of a spindle and the 
 gauge sticks shown in ¥\g. 62 the arm and rim cores were set. 
 
 The gauge stick shown in Fig. 63 and the templet of teeth shown 
 in Fig. 64 were used for setting the teeth cores. The templet being 
 used at the joints to see that the cores matched properly. This method 
 
32-11 
 
 MOLDING IN CORES 
 
 Fig. 64 
 
 Fig, 61. Core for T Section Frame 
 
 Fig. 64. Templet for Teeth 
 
 Fig. 65. Special Core Boxes 
 
 Fig. 66. Mold with some Cores set 
 
 ic* 
 
 Fig. 65 
 
A LARGE GEAR 
 
 33-11 
 
 of forming the teeth should be used only in cases where the teeth are 
 to be finished by cutting. For cast teeth a segment containing a num- 
 ber of teeth should be revolved about a spindle and the teeth rammed 
 up in sections. 
 
 Fig. 60. Arm Core Boxes 
 
 A photograph of the mold taken during the setting of the cores 
 is shown in Fig. 66. After the cores were all in place the space be- 
 tween as well as that between the walls of the pit and the tooth cores 
 was rammed with sand. 
 
 In Fig. 65 is shown a photograph of some of the special core 
 boxes used, which, together with the core boxes shown in Fig. 60, made 
 all of the cores necessary for the different parts of the mold. 
 
34-11 
 
 MOLDING IN CORES 
 CHAPTER VIII 
 
 THE USE OF NAIL CORES 
 
 The use of nail cores in perforated cast iron strainers for the intake 
 or suction end of pipes for pumps will be found a very simple and 
 economical method of executing work of this character. While the 
 manner of coring the holes is shown as applied to a strainer of cylin- 
 
 /tfOOOOOOOOO" 
 *0 OOOOOOOQo 
 
 ;oooooooooo 
 
 lOOOOOOOOOO 
 ('GOOOOOOOOO 
 V^vOOOOOOOOO o 
 \Oooooooooo 
 
 Fig. 67. A Strainer Head 
 
 drical form as shown in Fig. 67, it can be applied to almost any form. 
 It is particularly well adapted to flat work, such as strainer plates, fur- 
 nace door baffle plates, etc. The pattern is parted longitudinally and 
 
 Fig. 68. Pattern for Strainer Head 
 
 Fig. 70. Mold for Strainer Head 
 
 '!S'!^^f---i^'^wy<^\ 
 
 ^''^i^ddiii^&iiiiiiiM 
 
 Fig. 71. Body Core for Strainer Head 
 
 turned up as shown in Fig. 68. It will be observed that the core print 
 is turned with a shoulder A, this being done to insure its proper setting 
 into the mold. The mold having been rammed up in the ordinary 
 
NAIL CORES 
 
 35-11 
 
 manner and the pattern drawn, the nail cores, as shown in greater 
 detail in Fig. 69, are set at proper intervals around the mold as shown 
 in Fig. 70. The body core shown in Fig. 71 is then placed in position 
 and supported by the nail cores. These cores are similar to those com- 
 
 m^mmmm 
 
 
 ^Nail 
 
 Figr. 69, Core Box for Nail Cores 
 
 monly used in coring babbitt anchorage in bearings. They are formed 
 in a multiple core box as shown in Fig. 69, the hole B permitting the 
 nail to be inserted through the core before the box is turned over upon 
 the plate. 
 
SECTION III 
 
 SWEEP WORK 
 
 CHAPTER I 
 SWEEPING A PLAIN CYLINDER 
 
 Cylindrical castings, such as that shown in Fig. 1, are frequently 
 molded in loam by using sweeps which contain a radial section of the 
 cylindrical portion of the casting. These sweeps are revolved around 
 spindles and used to shape the material for the mold. Where cast- 
 
 CASTlNia 
 
 am 
 
 m 
 
 Fig. 1. Cylinder Casting 
 
 ings are to withstand high pressure it is claimed that stronger and 
 better castings having closer grain and denser metal can be made in 
 loam than in green sand. 
 
2-III 
 
 SWEEP WORK 
 
 In this chapter we will treat both the rigs made in the foundry 
 and those furnished by the patternmaker, as the exact method of 
 handling the work cannot be understood in any other way. It is first 
 necessary to make a foundation plate and a parting ring for support- 
 ing the inside and outside portions of the mold. The foundation plate 
 is shown in section in Fig. 2, and both the foundation plate and the 
 parting ring in section in Fig. 4. These plates or rings are usually 
 made in open sand molds by using segment patterns. 
 
 After the rings or plates are completed, the foundation plate is 
 leveled up with the spindle spider, or socket firmly imbedded below, 
 as shown in Fig. 2. The upper end of the spindle is held in place 
 by a bearing connected with braces which extend to the walls or to 
 suitable supports built up outside of the mold. 
 
 WALL BRACE 
 
 ■^^^^^55^^ 
 
 GREEN SAND FLANGE 
 LOAM 
 
 Fig. 2. First Sweeping Operations 
 
 The first sweep used in constructing the mold is shown at A, Fig. 2. 
 In using any sweep it is always secured to the spindle in such a way 
 that it is free to revolve about it. The sweep A is used to form the 
 seat or offset parting, which is built up of brick with a loam facing 
 sweep over it as shown. 
 
 After the loam has been swept in place, the cleat B, together with 
 the piece connected to it, is removed. This leaves an opening in the 
 sweep having a form like a cross section of the lower flange of the 
 desired casting. A green sand flange is then swept up on top of the 
 loam, as shown in the right of Fig. 2. This is skin dried and is sub- 
 sequently covered over with loam and brick to form the lower flange 
 of the casting. The green sand can be easily removed when the mold 
 is taken apart. Some molders prefer a pattern made for this flange, 
 as shown in Fig. 3. 
 
 After the flange has been placed or swept upon the seat, the part- 
 ing ring for supporting the outer wall of the mold is placed upon the 
 parting, as shown in Fig. 4. The sweep C is then secured to the 
 
A PLAIN CYLINDER 3- III 
 
 spindle, as shown, and brick work built up upon the cast iron ring 
 and loam placed upon it and swept off with the sweep C, as shown. 
 The loam, of course, is given the proper form by revolving the sweep 
 C about the spindle. 
 
 Patterns are made for the branches, or nozzles, upon the side of 
 the castings shown in Fig. 1. This pattern is shown in detail in Fig. 5 
 and its setting in Fig. 4. These patterns are set by lines or are secured 
 in their proper position by temporary supports and braces during the 
 building of the outer portion of the mold. The core print A on the 
 nozzle patterns is to form a seat for the covering core which forms 
 the outer face of the flange and through which pass the cores for the 
 inside of the nozzles. 
 
 Fig. 3. Pattern for Lower Flange 
 
 After the outer wall is completed and the flange and parting swept 
 at the top, the sweep is taken out and this portion of the mold removed 
 and dried in an oven. 
 
 The main or central core is next swept up by using the sweep E, 
 shown in Fig. 6. The lower arm F of the sweep is removed when 
 the brick work has reached this height. The completed portion of the 
 surface will act as a guide for the lower end of the sweep, while the 
 remainder of the brick work is being built up and the loam swept on 
 to it. When the core has been built to the required height, it is left 
 in the position in which it was swept and the plate with the seat and 
 core placed in an oven and dried. 
 
 A vertical section of the completed mold is shown in Fig. 7. In 
 order to arrange the parts as shown, the foundation plate with the 
 seat and core upon it is taken from the oven and carefully leveled up 
 
4-III 
 
 SWEEP WORK 
 
 in the casting pit. The cast iron ring, with the outer portion of the 
 mold, is next lowered in place. The circular covering cores for the 
 nozzles are then placed in position and the central nozzle cores intro- 
 duced through them as shown. 
 
 WALL BRACE 
 
 PARTING 
 IN MOLD^ 
 
 Fig. 4. Sweeping the Body of the Cylinder 
 
 Fig. 5. Nozzle Pattern 
 
 After the nozzle cores have been set, the space between the brick 
 work and the mold is rammed up with sand to form a backing for the 
 mold. 
 
A PLAIN CYLINDER 
 
 5-III 
 
 Slab cores are used to cover the top of the mold and suitable gates 
 are cut through these slab cores and a pouring basin formed. Of 
 course it is necessary to use weights for holding down the slab cores 
 and the different parts of the mold. 
 
 In the case of deep molds in which the iron would have to fall 
 several feet from the gates, there is danger of cutting the mold by the 
 first iron introduced and in such cases auxiliary gates are frequently 
 formed by making a suitable gate into the lower flange and then ram- 
 
 Fig. 6. Sweeping the Body Core 
 
 ming up gate sticks in the sand backing, or by introducing a gate made 
 in cores while ramming up the sand. 
 
 The pouring basin is so arranged that the first iron will pass down 
 through the bottom of this gate and into the bottom of the mold. 
 After the bottom of the mold is thoroughly covered with molten iron, 
 the ladle may be tipped faster and the metal introduced both from the 
 bottom and from the top through suitable gates in the covering cores. 
 
 For such a mold as this the patternmaker has to furnish the sweeps 
 shown, together with the patterns and core boxes for the nozzles and 
 in some cases the segment pattern for the foundation plate and the 
 
6-I1I 
 
 SWEEP WORK 
 
 lifting ring. He also has to furnish a core box for the slab covering 
 cores. In such work as this, care should be taken to see that the 
 nozzle patterns are so formed that there is a small amount of clearance 
 between the edge of the sweep and these parts. 
 
 
 •mM. 
 
 m 
 
 m 
 
 
 
 Fig. 7. Section of Finished Mold 
 
 As the lower parts of deep molds of this nature are apt to strain 
 or swell, from the pressure of metal forcing the walls out and causing 
 increased thickness of metal, it is often found practical to reduce the 
 section of the lower part of the mold by setting the sweeps in a slightly 
 inclined position. 
 
SUCTION CHAMBER MOLD 
 
 7-III 
 
 CHAPTER II 
 
 SWEEPING THE MOLD FOR A SUCTION CHAMBER 
 
 In the previous chapter there was described the sweeping of a 
 comparatively simple mold in loam, together with the rigs necessary 
 for the job. In this article will be described the molding of a suction 
 chamber which differs from that shown in Chapter I on account of 
 the fact that it is necessary to build up and sweep a temporary seat or 
 cradle to assist in forming and drying the main core and also on 
 account of the method employed for supporting and setting the core 
 by means of a cope ring. This casting also serves to show how 
 irregular partings can be made at any desired point in a mold. 
 
 Fig. 8. Suction Chamber 
 
 In preparing the rigging for a job of this kind, the patternmaker 
 has to lay out a full sized radial section of the piece to be molded 
 and then to make the necessary sweeps and part patterns, together 
 with the core boxes for the latter. It is also necessary to make any 
 strips, sweeps, or segmental patterns which may be required for mak- 
 ing open sand molds for lifting plates, cope rings, etc. 
 
 Ill the mold under discussion, which is shown in cross section 
 in Fig. 14, it is necessary to provide some support for the cope. For 
 this purpose a plate, similar to the one shown in Fig. 9, 'must be gotten 
 out, but it is not necessary to have the projection at the right, the plate 
 being circular with four bolting lugs. 
 
 In carrying on the work it is first necessary to get out a founda- 
 tion plate F, shown in Fig. 10, level it up and place the spindle S, 
 taking care to see that it is plumb. The sweep A is then secured to 
 
8-III 
 
 SWEEP WORK 
 
 the spindle and the lower half of the nozzle pattern held in position 
 by suitable supports as shown. The nozzle pattern must be set in such 
 a position that the sweep just clears it. For setting this pattern the 
 straight edge shown in the upper right hand corner of Fig. 10 will be 
 found very handy. This is arranged with a notch A in the straight 
 
 Fig. 9. Parting Plate 
 
 Fig. 10. Setting of Sweep and Port Pattern 
 
 edge cut to such a depth that when it is placed in contact with the 
 spindle the straight edge is in line with the center of the spindle, — in 
 other words, lies in a radial section. 
 
 Fig. 11. Sweeping the Seat or Cradle 
 
 The lower half of the nozzle pattern should be placed first and 
 held in position by a weight, while the lower portion of the mold is 
 being built. 
 
SUCTION CHAMBER MOLD 
 
 9-III 
 
 The circular portion of the mold below the cope ring G, Fig. 10, 
 is built up of brick work covered with loam and swept ofif with the 
 sweep A. When the brick work with its loam facing is complete to 
 the joint, an offset parting is formed as shown at P, Fig. 10. 
 
 The cast iron plate G, shown in detail in Fig. 9, is then placed 
 upon this parting, the cope half of the nozzle pattern set in place, and 
 
 Figr. 12. Building the Core 
 
 the brick work and sweeping continued until the top of the mold is 
 finished by sweeping it to the proper form for the flange and also 
 sweeping the seat to receive the covering plate. 
 
 The sweep and spindle are then removed and the portion of the 
 mold above the parting lifted off. The pattern is then drawn, the 
 
lO-III SWEEP WORK 
 
 opening at the bottom of the mold through which the spindle passed 
 is patched up, and the opening left for the support of the nozzle pat- 
 tern are also patched. The mold is then blacked and placed in the 
 oven to dry. 
 
 If this were a small casting it would be possible to sweep up the 
 core in a reverse position and then roll it over, but in the case under 
 consideration the casting is too large for this method and hence it will 
 be necessary to sweep up a seat or cradle in which the lower portion 
 of the core can be built. To do this a plate F, Fig. 11, is leveled up 
 and the spindle A set perpendicularly and supported at the top. 
 
 Fig. 13. Sweeping the Covering Plate 
 
 The sweep B is then secured to the spindle, brick work built up. 
 loam applied and swept off, so as to form the seat or cradle as shown 
 in Fig. 11. Care must be taken to see that the interior of the seat 
 conforms exactly with the desired interior surface of the casting. 
 
 The cradle is then slightly dried, after which the core is built up 
 in the manner shown in Fig. 12. 
 
 First, a core plate or lifting plate L is placed in position at the 
 lower portion of the mold. Loam is placed betw^een this and the sur- 
 face of the cradle, and the space below, between and below the prickers 
 which extend from the plate, is filled with molding sand which is 
 thoroughly rammed and supported with rods or gaggers. Of course 
 a loam facing is used next to the cradle after the space below the 
 plate L has been thoroughly filled brick work is built upon it with 
 a loam facing in contact with the cradle until the upper edge of the 
 cradle is reached. 
 
 The upper or parallel portion of the core is then built up and 
 swept off with the sweep C, as in the case of any plain cylindrical 
 piece. The outline of the upper portion of the core is shown by the 
 dotted line. 
 
 It is next necessary to make the covering plate, which serves both 
 to cover the mold and to locate the core centrally. The manner of 
 constructing this is shown in Fig. 13. The plate P is first leveled up 
 
SUCTION CHAMBER MOLD 
 
 ll-III 
 
 wrong side up and loam applied over the prickers and struck off with 
 the sweep D. This plate is provided with holes H, through which 
 bolts can be passed and secured to the lifting lugs H, in Fig. 12. After 
 the loam has been swept on this plate and dried it is turned over upon 
 the core shown in Fig. 12 and the two are bolted together as shown 
 in the assembled mold in Fig. 14. Of course it is necessary to dry the 
 core before applying the cover plate. 
 
 Fig. 14. Section of Mold 
 
 The various parts of the mold are now ready to assemble as shown 
 in Fig. 14. First, the core for the nozzle is placed in position and sup- 
 ported upon chaplets. Xext, the cast iron plate G carrying the upper 
 portion of the outside of the mold is lowered upon the portion already 
 in position, care being taken to place the necessary chaplets for holding 
 down the nozzle core before the upper portion of the mold is lowered 
 upon it. 
 
 Next, the cast iron ring or cover plate, together with the core, are 
 lifted from the cradle and lowered into position. At first they are 
 lowered carefully while strips of clay are interposed at various points 
 to test the metal thickness. The parts are then separated and if the 
 metal thickness is correct, the parts are assembled and bolted together 
 ready for casting. 
 
 The cover plate is bolted down to the foundation plate as shown, 
 and the space around the outside of the mold in the pit is firmly rammed 
 with sand. The gating of the mold will vary according to the indi- 
 vidual tastes of the molder in charge of the work. In many cases the 
 gating is arranged either by ramming up gate sticks or by placing 
 cores in the sand backing. 
 
12-III 
 
 SWEEP WORK 
 CHAPTER III 
 
 SWEEPING CAST STEEL SLAG LADLE MOLDS 
 
 When slag ladles are of cylindrical form, as shown in the two 
 half elevations, Fig. 15, the mold is usually formed with sweeps, the 
 striking edges of which contain radial sections of the interior and ex- 
 terior forms of the ladle to be cast. The sweeps are attached to and 
 revolve about a perpendicular spindle with the aid of sleeves and a 
 collar. 
 
 Fig. IS. Cast Steel Slag Ladle 
 
 At the right in the illustration is shown the half elevation of the 
 ladle containing one of the trunnions, while at the left is shown a half 
 elevation at right angles to the other, so as to show one of the tipping 
 lugs. 
 
 The pattern work for such a job requires the laying out of a full 
 sized radial section of the ladle, and the making of the sweeps and 
 fitting them to the spindle, the making of the core prints for that 
 portion of the trunnion core which extends into the cope, and the neces- 
 sary core boxes for the trunnions and tipping lugs. 
 
 When sweeping up molds for ladles of small diameter, say below 
 four feet, as the one under consideration, a skeleton or built-up bottom 
 
A SLAG LADLE MOLD 
 
 13-IIT 
 
 as shown in position in Fig. 16, is usually made to form th;s portion of 
 the mold. The use of such a partial pattern affords a surface for the 
 molder to stand upon while using the sweep and finishing the mold. 
 
 SPINDLE SOCKET 
 
 Fig. 16. Sweep in Place 
 
 After the completion of the preliminary pattern work, the molder 
 
 takes the job in hand and begins operations by digging a hole in the 
 
 floor to the depth of the ladle to be cast and firmly placing the spindle 
 
 socket in position. 
 
 The built up portion of the bottom of the ladle pattern is now 
 
 placed in the bottom of hole and the spindle passed through the hole 
 
14-III 
 
 SWEEP WORK 
 
 in its center and seated in its socket as shown. The spindle is then 
 plumbed and the wall or post braces adjusted. Next, the partial pat- 
 tern is leveled up and firmly bedded in place. 
 
 With the upper edge of the part pattern for a guide two surfaces 
 are struck off diametrically opposite each other to receive the lug cores. 
 These cores are prepared for insertion in the mold by stopping up the 
 openings with waste or some other suitable material. 
 
 During the sweeping of the inner surface, the lugs are set back 
 from the first sweep a distance equal to the metal thickness by the 
 aid of a strip bradded on to the side of the sweep. The lug cores are 
 
 SECTION OC 
 Fig. 17 
 
 I^ 
 
 a 
 
 SECTION DO 
 
 Fig. 19 
 
 SECTION ££ 
 Fig. 20 
 
 Fig. 17. Core Print for Trunnion Fig. 19. Half Core Box for Tipping Lug 
 
 Fig. 20. Half Core Box for Trunnion. 
 
 shown in position in Fig. 16, together with the arrangement of the 
 sweep during the two operations of sweeping. That is, the sweeping 
 up of the inner form upon wdiich the core is rammed and the subse- 
 quent sweeping off of the metal thickness. 
 
 The sw'eep is attached to the spindle as shown and as the use of 
 an ordinary solid sleeve causes more or less inconvenience in placing 
 and removing sweeps, a split sleeve as shown in the upper left hand 
 corner of Fig. 16 can be used to very good advantage. 
 
 The sweep is constructed as shown in Fig. 16, being provided with 
 a detachable strip A, equal in width to the required metal thickness of 
 the ladle. A cross section of the sweep on the line U U with the at- 
 tached strip A is shown in detail at the left of Fig. 16. 
 
 After the completion of the bedding in of the ]:)art pattern and the 
 Jocation of the two lug cores, the sweep without the strip .\ is attached 
 
A SLAG LADLE MOLD 
 
 15-III 
 
 and the inner form of the ladle swept up, a parting being made for 
 the cope as shown at the right of the spindle in Fig. 16. The sweep 
 and the spindle are then removed and the opening in the part pattern 
 through which the spindle passes stopped up with waste to prevent 
 the sand ramming into it. 
 
 /RUNNER 
 
 •RISER 
 
 
 
 
 SM'A 
 
 JION 
 rOREBEDDED IN 
 
 vMw^-'^' 
 
 mm 
 
 m£mm 
 
 ill 
 
 Jlfr^ — CAST IRON GRATE 
 
 ¥ 
 
 Fig-. 18. Section of Mold 
 
 With the aid of a straight edge and plumb bob the center line of 
 the trunnions is scribed across the parting of the mold at right angles 
 to the center line of the tipping lugs and the two core prints are placed 
 in position. 
 
 One of these core prints is shown in greater detail in Fig. 17. 
 These prints are set diametrically opposite each other and on a line at 
 right angles to the center line passing through the tipping lugs. 
 
 Parting sand is next applied to the parting of the mold and the 
 interior cylindrical surface of the ladle covered with paper. A grate 
 
16-III SJVEEP WORK 
 
 or crab iron conforming somewhat to the form of the bottom of the 
 core is next placed in position and provided with bolts of such a length 
 that they will extend up through the cope. This crab iron is shown 
 in Fig. 18. When ramming up the core a thickness of silica sand is 
 placed around the outer surface. Ordinary heap sand is used back of 
 this and the interior of the core filled with coke. 
 
 When the ramming of the core, with its filling of coke, has reached 
 the height of the parting line, the cope is placed on and staked in 
 position. The core is now securely bolted to the cope. After the cope 
 has been rammed, the cope, with the attached core, is lifted off, blocked 
 up and finished. The outline of the two trunnion core prints is marked 
 upon the parting by scribing a line around them, after which our 
 attention is turned to the obtaining of the proper metal thickness. 
 The swept surface of the interior of the mold is first roughed off with 
 a shovel to a depth equal to the metal thickness of the ladje plus the 
 thickness of silica facing to be used. The strip A is next attached to 
 the sweep and the spindle returned to its proper position. The outer 
 portion of the mold is then swept up with its silica facing, thus giving 
 the required thickness of metal for the ladle. The depth of the trunnion 
 cores is laid off on the sweep and transferred to the surface, after 
 which the sweep and spindle are removed. 
 
 Guided by the outline of the core prints scribed on the parting and 
 the lines scribed on from the sweep, an opening is cut out on each 
 side of the mold and the trunnion cores bedded in in the proper position, 
 as shown at the right in the view of the cross section of the completed 
 mold in Fig. 18. At the left of Fig. 18 is shown a view of the cross 
 section of the completed mold through a tipping lug, together with 
 the arrangement of gates and runners required. 
 
 After the setting of the trunnion cores has been completed the in- 
 side of the mold is dressed and the part pattern removed. The spindle 
 hole is then filled up and the bottom portion of the mold slicked up and 
 finished. This, as will readily be seen, is a rather awkward operation. 
 
 The mold is then given a silica wash and dried. The cope is sub- 
 sequently placed on and tried for metal thickness and if found correct, 
 is securely weighted down, when the mold awaits the metal. 
 
 The core boxes for forming one-half of the lug and trunnion cores 
 are shown in Figs. 19 and 20. Two half boxes are required for each 
 core. 
 
MOLDING A FURNACE BELL 17-III 
 
 CHAPTER IV 
 
 A FURNACE HOPPER AND BELL 
 
 A cross section of a blast furnace hopper and bell of familiar 
 design is shown in Fig. 21. These castings are frequently made from 
 steel, and vary in diameter from 6 to 12 feet. When exceeding these 
 proportions, they are usually cast in sections which are bolted together. 
 
 While the sweeping or forming of molds of this description is com- 
 paratively simple, it may embrace some points of interest. The method 
 frequently adopted is shown in the accompanying illustrations and will 
 serve to familiarize the patternmaker with this character of work, in- 
 cluding the laying out and making of the accompanying sweeps, etc. 
 
 Fig-. 21. Section of Bell and Hopper 
 
 The bell being of conical form can be cast in either position, but 
 is usually cast with the apex down, as this insures a better casting and 
 allows risers to be placed upon the rim. This position also permits 
 the inside to be lifted out with the aid of a skeleton or lifting plate. 
 
 Molding- the Bell 
 
 In beginning the work, a hole is dug in the floor equal in depth 
 to the height of the bell and the spindle is set and plumbed as shown 
 in Fig. 22, wall braces being used to secure the upper end and to hold 
 the spindle rigidly. 
 
 Shown in Fig. 23 is a partial pattern containing the apex of the 
 bell and to which is secured the core print with the lifting lugs or ears 
 attached. This part pattern is provided with a hole through the center 
 to receive the spindle and to locate it in the proper position. It is 
 firmly bedded in, forming the lower portion jf the mold, as shown in 
 Fig. 22. 
 
18-1 I I 
 
 SWEEP WORK 
 
 Attention is also called to the manner of supporting the lower 
 end of the spindle upon a center, as shown in I'^ig. 22. The advantage 
 of this method is that any dirt which may be dropped into the hole will 
 not interfere with the spindle. 
 
 The sweep is constructed as shown in Fig. 22 and provided with 
 a detachable strip D, equal in width to the required metal thickness 
 of the bell. A cross section of the sweep on the line C-C, with the 
 
 Wan Brace 
 
 'l^^^rj!f^^:>K 
 
 SECTION C-C 
 
 Fis. 22. Spindle Set for Sweeping the Stopper 
 
 attached strip D, is shown in greater detail to the right in Fig. 22. 
 The sweep is attached to the spindle as shown. The split sleeve shown 
 in Mg. 16 may be used in this case. This allows the sweep to be at- 
 tached without disturbing the spindle, the sleeve being provided with 
 a clamp secured with a bolt. 
 
 There are two methods whicli may be used for sweeping up pieces 
 of this description. Mrst, sweeping up of the inner surface or form 
 of the required object, and then the sweeping off of the metal thick- 
 ness after the central portion or core has been made. Second, the 
 
MOLDING A FURNACE BELL 
 
 19- III 
 
 sweeping up of the outer surface or form of the object, applying of 
 parting sand, and then with the strip D removed, the sweeping on of a 
 thickness of sand equal to the thickness of the metal, after which the 
 core is rammed up on this surface. The thickness of sand forming 
 the metal thickness is removed during the finishing of the mold. 
 
 The method discussed in this article will be the first mentioned 
 process, which is the one usually adopted in steel foundries. At the 
 completion of the bedding in of the part pattern, the sweep without 
 strip D is attached and the inner surface or form of the mold is swept 
 up and the parting for the cope made, as shown in Fig. 22. 
 
 -Hole for Spindle, 
 
 ■ Core Print___y^jYvHl-TlX '' 
 
 Fig. 23 
 
 Fig. 23. Pattern for Ape.x of B 
 
 Fig. 26 
 
 Fig. 26. Core Bo.\ for the Ears or Lugs 
 
 The spindle sweeps, etc., are then removed, and the hole for the 
 spindle in the part pattern stopped up. Parting sand is freely applied, 
 and the skeleton shown in Fig. 24, with rods upon it to conform some- 
 what to the shape of the mold, is placed in position and the ramming of 
 the core begun. 
 
 At the completion of the ramming of the core, the cope or flask is 
 placed on and firmly rammed up, being securely bolted together some- 
 what after the manner shown in the cross section of the complete mold, 
 Fig. 25. 
 
 The cope with the core attached is now lifted off, blocked uo, 
 finished and dried. The inner surface of the mold is then roughed 
 out, the spindle and sweep replaced, and with the strip D attached, the 
 outer surface or form swept up, giving the required metal thickness. 
 The spindle and sweep are then removed, the part pattern drawn, the 
 mold finished, and the core forming the inside of the lugs, or ears, 
 placed in position. The gate is arranged and the mold is dried. 
 
20-111 
 
 SWEEP WORK 
 
 The cope is now placed on, and if the metal thickness is found 
 correct, the whole is weighted or bolted down, and prepared for casting. 
 
 Two views of the core box used for forming the ears or lugs are 
 shown in Fig. 26. 
 
 Molding the Hopper 
 
 In tiiis particular case, the molding of the hopper differs from 
 that of the bell, inasmuch as only the outer surface is formed with a 
 
 IT' 
 
 r'fi^-i r ^- r^ 
 
 _.4i__,___j_-t^ 
 
 P'^. 
 
 ^^m^^ 
 
 ^Ss 
 
 .^^' 
 
 ^. 
 
 Skpletoii 
 
 w 
 
 ^ 
 
 V 
 
 Fig- 24. Skeleton for Core 
 
 
 Fisr. 25. Section of Mold 
 
 sweep, the inner surface being obtained with the aid of lagging and 
 strips in thickness equivalent to the metal thickness of the hopper. 
 These lagging pieces being used as shown, the strips are placed at in- 
 tervals around the mold, forming a guide by which the required depth 
 can be struck off from the core, to give the proper metal thickness. 
 
 A cross section through the center of the mold for the hopper is 
 shown in Mg. 27. To the right of the spindle is shown the construc- 
 tion and arrangement of the sweep, as it appears during the operation 
 of sweeping the outer surface or form of the mold with the flange and 
 parting at the top, also the seat for locating the core. 
 
MOLDING A FURNACE HOPPER 
 
 21-III 
 
 At the left of the illustration, the form of the mold after sweeping 
 is completed, is shown, with the lagging and strips for giving the metal 
 thickness, in place. 
 
 The outline and position of the covering core is also shown in 
 dotted lines. 
 
 The operation of sweeping being complete the spindle and sweep 
 are removed and parting sand or paper applied to the swept surface. 
 Paper is generally applied to the walls of the mold. 
 
 Fig. 27. Section of Hopper Mold with Sweep in Place 
 
 The undersweep surface G is now filled in with lagging, so as to 
 close off this depression, and the metal thickness strips are placed in 
 position. A core bar, consisting of a series of round flasks of con- 
 venient diameter and depth, which have been firmly clamped and 
 bolted together, and provided with wing bars bolted to their outer 
 diameter, is now lowered into the mold and centrally located upon the 
 seat. Sand is firmly rammed and rodded into the inclosure formed 
 by the outer diameter of the flasks and the swept surface of the mold, 
 the top being furnished with a seat or surface to receive the covering 
 core. This is accomplished with the aid of a segment conforming to 
 the swept core seat and flange and applied in the manner shown in 
 Fi^. 29. 
 
22 III 
 
 SWEEP IVCRK 
 
 The core bar, made up of flasks, is now lifted out with the sand 
 core intact and blocked up. The thickness strips are removed and with 
 these depressions acting as guides for the depth, the metal thickness 
 is struck ofif and the core finished and dried. 
 
 Segment 
 
 FI9. 30 
 
 Fig. 31 
 
 Fig. 28. Segment to Form Seat for Covering Core Fig. 30. Core Box for Covering Cores 
 
 Fig. 31. Use of Cores to Form Inside of Mold 
 
 Covering Core 
 
 Fig. 29. Completed Mold 
 
 The lagging in the portion of the mold G, Fig. 27, being removed 
 the mold is treated in the usual manner. The parts are then assembled, 
 as shown in the cross section of the complete mold, Fig. 29, the cover- 
 ing cores being formed in the box shown in Fig. 30. 
 
 These are used to form the upper surface of the flange and close 
 
MOLDING A FURNACE HOPPER 23-III 
 
 the top of mold, openings being filed in a number of these covering 
 cores at different points around the mold, at which points risers are 
 built up. 
 
 The runner is arranged through the center of the mold or flasks, 
 and the castings gated from below. The whole structure is then 
 weighted down and prepared for casting. 
 
 Another method practiced in some cases is illustrated in Fig. 31. 
 In this case, cores are used to form the inner surface of the mold and 
 the upper face of the flange. The inner surface or form of the mold 
 with the seat for the cores at the top and bottom is swept and dried in 
 the manner already described, after which the series of cores are placed 
 around the inside of the mold, §o as to form the metal thickness, pro- 
 vision of course being made for the runner and gating, after which 
 sand is firmly rammed within the inclosure formed by the cores form- 
 ing a solid core. 
 
24-III 
 
 SWEEP WORK 
 CHAPTER V 
 
 SWEEPING A CYLINDRICAL AND CONICAL DRUM 
 
 The accompanying illustrations show a combined cylindrical and 
 conical hoisting drum with a variable pitch score, and also one method 
 of sweeping the same in loam. These drums, two in number, form a 
 right and left when placed together, and were designed by the Well- 
 man-Seaver-Morgan Co. They were used in the construction of an 
 electric automatic water hoist, in an anthracite coal mine near Scran- 
 ton, Pa. 
 
 Fig. 32 Cylindrical and Conical Drum. 
 
 This design of hoisting drum is employed in winding heavy loads 
 from deep mines. When the skip or load is at the bottom of the mine, 
 ready to be hauled up, the winding of the cable begins at the small 
 cylindrical end. This prevents the load from starting too suddenly, 
 and allows the slack cable in the shaft to be gradually taken up at the 
 beginning of the hoist. The motor or engine also gains a decided 
 advantage when these drums are employed, as the winding starts at a 
 slow speed and gradually increases, thus giving the motive power a 
 better chance to do its work, and reducing the strain to a minimum. 
 
 Fig. 32 gives a cross section of the drum ; to the right is shown 
 the metal thickness, and to the left the bolting flange with its splitting 
 
A CYLINDRICAL AND CONICAL DRUM 
 
 25-III 
 
 margin along the joint and around the bolt holes. The drum is cast 
 practically entire, and subsequently split in two. 
 
 It will be seen that the drum is 16 feet in diameter at the large 
 end, and 10 feet at the small end. The conical section is very flat, 
 
 Fig. 33. Plan of Drum 
 
 and increases from the small to the large diameter in four revolutions. 
 Fig. 2)2) gives plan of drum at the small cylindrical end, showing ribs, 
 bolting flanges, etc. 
 
 As the rig or device employed in producing conical drums of this 
 description is one of the principal features, upon which the accuracy 
 
 Fig. 34. Spindle Screw 
 
 of the work greatly depends, its calculation and construction usually 
 receive the initial attention, therefore we shall proceed in this wise. 
 
 Special Sweeping Rig 
 
 The variation in the axial pitch of the drum score was produced 
 by a variable pitch thread cut upon the cast iron hollow spindle, as 
 illustrated in Fig. 34. This thread receives the conical roller A, which 
 is provided with a roller bearing bracket B, as shown in plan and 
 
26-1 II 
 
 SWEEP WORK 
 
 section, Fig. 35. The outer diameter of the spindle is turned to the 
 required dimension, six inches, the variable pitch thread is laid off, 
 and holes drilled at the ])oints where the pitch of thread changes. The 
 spindle is then returned to the lathe, and the required pitch of thread 
 between the drilled holes cut, the spindle being finished at the top and 
 bottom as shown. 
 
 Fig. 35. Roller Bearing Bracket Fig. 36. Sweeping Rig 
 
 Three views of the assembled device are shown in Fig. 36, giving 
 the general construction of the frame. The material used is hard 
 wood. The sliding arm C is held in place as shown, and with the 
 aid of rollers D, is allowed to travel or slide freely. Gear E at the 
 
A CYLINDRICAL AND CONICAL DRUM 
 
 27-111 
 
 top of the frame is attached to the spindle with a feather key, per- 
 mitting it to travel up and down the spindle as the frame is raised or 
 lowered. As the frame is revolved around the spindle, gear E drives 
 gear F, which, by means of shaft G, pinion H, and rack I, causes the 
 sliding arm C to travel radially backward or forward, as the case 
 requires. 
 
 The raising or lowering of the frame is governed by the engage- 
 ment of the conical roller A, with the thread of the spindle. The 
 bracket B is located and secured to the lower part of the frame at J. 
 The proportion of gears governing the travel of arm C during the 
 sweeping of the conical section of drum is as follows: The angle of 
 the conical section is 120 degrees, giving a 9-inch throw to the 5-inch 
 pitch ; that is, the frame would rise 5 inches in one revolution, while the 
 arm C would travel outward 9 inches. The gears are of ^ circular 
 pitch, gears E and F having a pitch diameter of 10.15 inches, and 64 
 teeth; gear H contains 18 teeth with a pitch diameter of 2.86 inches. 
 
 Fig. 37. Foundation Plate and Spindle Setting 
 
 These proportions give the gears the same number of revolutions as 
 the frame. 
 
 When using the frame with the arm C stationary, as in the sweep- 
 ing of the cylindrical sections, gear E is thrown out of mesh with gear 
 F by being raised up and a block or support placed underneath it. 
 This also requires the disengaging of the roller from the thread of the 
 spindle. The frame is now held suspended and revolved upon the 
 collar K ; the collar being dropped down upon the spindle socket when 
 not in use. 
 
 Sweeping the Mold 
 
 The pit having been dug to the depth of the drum, a bed is struck 
 off for foundation plate A, which is placed in position and leveled up 
 with the spindle socket attached, as illustrated in Fig. 2)7. The socket 
 is bushed as shown, to receive an ordinary spindle, to which is attached 
 the sweep C. The brick work is now built up to the required height in 
 the usual manner, and a heavy facing of loam applied and struck off 
 
28-1 I I 
 
 SWEEP WORK 
 
 to the form of the sweep. The cutting edge of tlie swee]) forms the 
 seat for the core, and also a surface and guide for ])lacing flange D, 
 which is shown in position to the left. 
 
 Fig. 38 illustrates the rig in operation, showing the arm with the 
 various cutters and strikes attached, which are employed at the different 
 
 stages of sweeping the mold. To the right are shown the cutters G, 
 H and I, required in forming the score. They are made of ^-inch. 
 steel plate, dressed to form and the back beveled off, forming a com- 
 paratively sharp edge. To the left are shown the strikes J and Z, 
 employed in sweeping on a body of sand the equivalent of the metal 
 thickness. 
 

30-III 
 
 SWEEP WORK 
 
 With the seat for core prepared and flange D in position, the 
 scoring of the mold is in order. Following the plumbing of the spindle, 
 the frame is lowered down over it, and the upper end secured with 
 guy rods attached to flange L. With the roller engaged with the 
 thread of the spindle, the gear E thrown out of mesh with gear F, the 
 frame is placed in position at the starting point, this being governed 
 by the thread of the spindle. The slide with cutter G attached is next 
 adjusted to the required diameter of score, and the slide locked in 
 position, as shown to the right at the starting point. 
 
 The brick work with a heavy loam facing, which is struck off to 
 the form of cutter along its helical path, is now laid until the conical 
 section is reached. Cutter H is now attached to the slide as shown, 
 gear E dropped into mesh with gear F, causing the slide to travel out- 
 ward as the frame is revolved. 
 
 rRif 
 
 Fig. 42 
 
 Fig. 41. Grates for Holding the Core 
 
 Fig. 41 
 
 Fig. 42. Sweeping of Coven'ng Ring 
 
 As the changing of these cutters and pitch of scoring is rather 
 abrupt, a little doctoring or making up of score becomes necessary at 
 this point, and is accomplished with the aid of a segment representing 
 a section of scoring. The segment is so dressed that it works from 
 one section to the other. This mending up also becomes necessary 
 when the large conical and cylindrical sections meet, at which time 
 cutter I is attached, and the bricking and scoring completed to the top. 
 
 At the top a surface to receive the covering ring is struck off with 
 the aid of strike AI, attached to the slide, as shown to the left. This 
 necessitates the throwing out of the gears and conical roller, the frame 
 being supported and revolved upon the collar K. 
 
 With this porti(in of the mold completed and air-dried, a body of 
 ordinary sand, equivalent to the metal thickness, is then swept on. The 
 gears and conical roller having been disengaged, the strike Z attached, 
 and the slide locked to the inside diameter, the frame is lowered until 
 the strike clears the flange D, and the collar K adjusted. This thick- 
 ness of sand is now swept up on the small cylindrical section of the 
 mold, as shown. 
 
A CYLINDRICAL AND CONICAL DRUM 
 
 31-111 
 
 The conical section being reached, the strike T is attached, the 
 conical roller engaged with the thread of the spindle, and the gears 
 dropped into mesh and this thickness of sand swept up on the conical 
 section. The large cylindrical section is treated like the small section, 
 strike Z being employed. 
 
 The frame and spindle are now removed, paper applied to the seat 
 for the core, a heavy loam facing spread over it, and the lifting plate N, 
 upon which the core is built, as shown in cross section of mold, Fig. 
 39, pressed down upon it ; to which it adheres, forming a seat and guide 
 for locating the core when returned to the mold. The ribs and bolting 
 
32-111 
 
 SWEEP WORK 
 
 flanges, Fig. 40, with splitting and bolt core prints attached, are now 
 placed in position. They support the flange E, as shown in Fig. 40. 
 This flange and flange D are in sections, which allows their being 
 drawn in or back, as the case requires. The arrangement of ribs, etc.. 
 
 is screwed together, the screws being removed as the building of the 
 core progresses. 
 
 Building the Core 
 
 The bricking, strengthened with rods and plates, having a thick- 
 ness of loam between it and the molding sand thickness, which repre- 
 sents the metal thickness of the drum, is now placed upon the lifting 
 
A CYLINDRICAL AND CONICAL DRUM 33-III 
 
 plate N, Fig. 39, until the conical section is reached. Open sand grates, 
 as shown in Fig. 41, are now employed to secure the overhanging brick 
 and loam, the grates increasing in length as the building of the core 
 progresses. The small end is kept somewhat in line, allowing the 
 sixteen clamping bolts to pass up through them. The height of the 
 conical section is built up in this manner ; plate P, Fig. 39, is placed 
 upon the grating with its filling of brick and loam, and this portion of 
 the core securely clamped together. Brick and loam are now applied 
 to the top of the plate, and the remaining portion of the core com- 
 pleted and the top finished, as shown. 
 
 A center line for the splitting core is now laid off across the top 
 of the core and outer wall of the mold. 
 
 The lifting plate is provided with four staples, as shown. The 
 core is lifted from its seat with the aid of a four-way cross, as shown 
 in Fig. 43, and placed upon a car, the ribs and flanges drawn, the core 
 dressed and placed in the oven and dried. 
 
 The lower flange is drawn and the sand forming the metal thick- 
 ness is removed from the mold, it is then treated in the usual manner, 
 and thoroughly dried by the aid of coke fires placed in it. 
 
 Owing to the deep scoring of the conical section of the drum, the 
 splitting of the projecting metal between the score is an object to be 
 considered. This can be overcome to a nicety with ^-inch steel rods 
 in the following manner : By the aid of a plumb-bob and straight-edge 
 across the top of the mold, the center line of the drum at the splitting 
 core is projected down the side of the mold, and ^-inch machine steel 
 rods driven in opposite these projections, as shown to the right in 
 Fig. 39. This same figure also shows the splitting and bolt cores in 
 position. The bolt cores are placed through the splitting core, but 
 independent of it, being secured by the tail prints, leaving a j/2-inch 
 metal thickness around the bolt holes. 
 
 The splitting core consists of a perforated ^-inch cast iron plate, 
 covered with loam, forming a core of about ^^-inch in thickness. To 
 facilitate the handling and setting of these cores, and to lessen the 
 danger of the cast iron plate warping or expanding when heated from 
 the metal, thus causing the loam to crack and chip from the plate, the 
 cores are made in three sections. A complete core box is used, the cores 
 being separated by the introduction of pieces of tin at the desired 
 lengths. The splitting preparations being completed, the mold is ready 
 to be assembled. 
 
 The core is lowered into place, and the cope ring placed on. This 
 ring consists of a cast iron prickered semi-ring, or plate, provided with 
 lifting lugs and openings for gating. To the prickered surface a heavy 
 
34-III 
 
 SWEEP WORK 
 
 facing of loam is applied, and struck off with the aid of a spindle and 
 sweep, as shown in Fig. 42. 
 
 The clamping of the mold is accomplished with the assistance of a 
 six-way cross in a very positive manner. Foundation plate A is pro- 
 vided with lugs corresponding with the arms of the cross, and the tie 
 rods are attached to it, as shown. The crane is now hooked on to the 
 cross, and given a heavy lift, and while being subjected to this strain, 
 the blocking between the covering ring and cross is placed in position 
 and securely wedged up. 
 
 The intervening space between the wall of the mold and the side 
 of the pit is firmly rammed in with sand. The runners, two in num- 
 ber, are located opposite each other, and are prepared during this ram- 
 ming or backing up. 
 
 Fig. 45. Finished Casting 
 
 The gating to the lower flange is not on a radial line, as shown to 
 the left, Fig. 39 (this being simply for illustration), but is carried 
 farther around the flange so as to cause the metal to whirl or circulate 
 as it rises in' the mold; this provision being necessary to offset the ten- 
 dency of the metal to become sluggish or chilled as it nears the top. 
 
 The pouring of the mold does not depend entirely upon the gating 
 from below, as the mold is provided with a series of pop gates closed 
 with cast iron stoppers and connected with the pouring basin, as shown 
 in Fig. 39. During the pouring, and when the metal has reached the 
 top of the conical section, the ladles are tipped, choking the runners, 
 and causing the metal to back up over the pop gates to the depth of 
 
A CYLINDRICAL AND CONICAL DRUM 35-111 
 
 three or four inches. The stoppers are now Hfted out, causing the 
 metal to drop into the mold. 
 
 A photograph of the mold during the operation of sweeping is 
 shown in Fig. 44. 
 
 A view of the mold with the core suspended from one crane im- 
 mediately behind it and the six-way cross for tying down the cope sus- 
 pended from the other crane near it, is shown in Fig. 43. The finished 
 casting is shown in Fig. 45. 
 
36-ni SWEEP WORK 
 
 CHAPTER VI 
 
 SWEEPING RIGS 
 
 A Double Sweeping Frame 
 
 The accompanying illustrations show a convenient sweeping rig, 
 to which may be attached various strike boards, the striking edge of 
 which contain radial sections of the pieces to be swept up. As the 
 strike boards are rigidly and permanentl}' secured together with cleats 
 
 Fig. 46. Section of Dome Casting 
 
 they can be attached to or removed from the rig very quickly as the 
 case may require, no special adjusting being necessary. The advan- 
 tages of the rig can readily be seen, for if a casting is to be duplicated 
 all that is necessary is to go to the pattern storage, get the strike boards, 
 and attach them to the .Ig. 
 
 The blocks B-B, Fig. 47, upon the cleats which secure the boards 
 together guide the parts into their correct position upon the rig. 
 
 The rig is shown as applied to the sweeping up of a green sand 
 mold for producing a dome casting, as shown in half section and half 
 elevation in Fig. 46. 
 
 The assembled arrangement of the rig with the strike boards at- 
 tached is shown in Fig. 47. At the right of the spindle the operation 
 of sweeping the exterior form of the dome is shown in progress. Upon 
 this sweep surface the cope is subsequently rammed up. At the left 
 of the spindle the rig is shown in the reverse position or upside down, 
 as wnen set for sweeping off the metal thickness or striking up the 
 interior form of the dome. Of course, the striking up of the interior 
 form takes place after the ramming up and lifting off of the cope. 
 
 The separate parts of the arrangement are shown in Fig. 48. The 
 rig itself is shown at the left, and consists of a rigid frame made from 
 33^ X 1^-inch material, the frame being strengthened by cross braces, 
 as shown. The spindle sleeves are of the hinge design, as this form 
 of sleeve allows the rig to be attached to or detached from the spindle 
 without disturbing the latter ; that is, the spindle can be set up and 
 
A DOUBLE SWEEPING RIG 
 
 87-III 
 
 adjusted and the rig attached afterward. The sleeve is shown in 
 greater detail above the frame. 
 
 At the right of Fig. 48 are shown the strike boards as they would 
 appear when removed from the rig. Care should be taken in attach- 
 ing boards together to see that they are rigidly secured to the cleats 
 with screws and a spot of glue at the extreme ends of the cleats. There 
 are two advantages in this manner of gluing. First, any shrinking or 
 
 Fig. 47, Assembled Rig 
 
 swelling that may take place in the boards will be toward or from the 
 glue spots at the ends of the cleats and will prevent the striking edge 
 of the boards being distorted. Second, if glue was applied to the por- 
 tion of the cleats extending across the boards, warping of the boards 
 would be the result. In fitting the boards to the frame the latter is laid 
 down and the boards with the striking edge dressed to form, placed in 
 about their correct position and the cleats attached. 
 
 Next the centering pin shown directly above the striking boards 
 in Fig. 48 is used in locating the blocks B-B, Figs. 47 and 48. 
 
 These blocks should be securely fastened in place with glue and 
 screws. The centering pin is usually turned up from well-seasoned 
 hardwood, its diameter being the same as that of the spindle. A por- 
 tion of the center is cut out to half the diameter and the center line of 
 the pin scribed thereon. By shoving the pin through the sleeves as if 
 
38-III 
 
 SWEEP WORK 
 
 it were the spindle and turning the flcit side of the pin into the plane 
 of the striking boards, the center line upon the pin becomes immediately 
 ' available for setting the boards. 
 
 i 
 
 X 
 Centering Pin I 
 
 •ing Pin I JCenter Li 
 
 ^=^ I / ^ 
 
 Fig. 49 
 
 Fig. 48 
 
 —A 
 
 Fig. 48. Details of Sweeping Rig 
 
 Fig. 49, Eccentric Collar 
 
 An Eccentric Spindle Collar 
 
 The accompanying illustrations show an eccentric collar applied to 
 an ordinary foundry spindle for sweeping up circular molds. This is. 
 especially adapted to the sweeping up of circular work that is cast in 
 
AN ECCENTRIC SPINDLE COLLAR 
 
 39-1 I I 
 
 halves, the mold being divided or separated by what are termed split- 
 ting cores. 
 
 To split such work usually necessitates the shifting of the spindle 
 a distance equal to the thickness of the splitting core used. This is 
 often an awkward operation owing to the fact that the adjustment must 
 be made below the floor level. 
 
 Fig. 50. Eccentric Collar Rig in Use 
 
 The collar under description avoids such trouble very nicely, the 
 piece is bored out and turned up as shown in Fig. 49 with any desired 
 throw. The center line AA should be scribed distinctly across the face 
 of the collar. 
 
 This device is especially adapted for the molding of sections of 
 gears, etc., where a section of the rim or a segment is used in ramming 
 the outside diameter as shown in Fig. 50. To adjust the collar to the 
 arm of the rim or segment a hole is cut at the exact center of the work, 
 the diameter of the hole being sufficient to receive the portion of the 
 collar marked B, Fig. 49. 
 
 The spindle is first set and plumbed in the usual manner. The 
 collar is then slipped over it and secured by the set screw C at about 
 the right height from the bottom. The arm with the segment attached 
 
40-III SWEEP WORK 
 
 is now let down over the spindle and centered upon the collar which 
 holds it in the proper position and allows it to revolve upon the 
 shoulder D. 
 
 As is the general practice, the segment is first set around the en- 
 tire circumference, using flour to mark the correct position and spacing. 
 When the spacing is found to be correct, a straight edge is placed across 
 the center of the mold, as indicated by the dotted lines in Fig. 50. At 
 the center the straight edge is cut out to receive one-half of the collar 
 at the diameter B as shown. This brings the front edge of the straight 
 edge in line with the center of the gear and locates the stopping point 
 in ramming up this half of the wheel. Care should be taken in laying 
 off this center line to see that it is parallel with the center line A\ of 
 the collar. 
 
 After one half of the mold has been rammed up the center line AA 
 is marked on the spindle and the collar given a half revolution. The 
 other half of the mold is rammed up just like the first half, care being 
 taken to see that the space allowed for the spacing cores is equal on 
 the two sides of the mold. 
 
SECTION IV 
 
 GEARING 
 
 CHAPTER I 
 SPUR GEARING 
 
 The theoretically perfect gear wheel is a friction wheel communi- 
 cating a smooth, uniform rolling motion by means of frictional con- 
 tact of its surface. It is, in fact, a gear wheel with a great many very 
 small weak and irregular teeth. Such a gear as this is manifestly 
 imperfect, subject to slip, and on the whole not suitable for many 
 purposes. The whole object of the science of gear wheels is to increase 
 the size and strength of the teeth without destroying the uniformity of 
 the motion transmitted. This is accomplished by so forming the out- 
 lines of the teeth that they will produce the desired result. Theoreti- 
 cally, there are an infinite number of curves that will meet the require- 
 ments, but only two are of any practical importance or have come into 
 use to any extent. These are the epicycloidal and the involute. 
 
 Definitions 
 
 The spur gear is one whose teeth are parallel to its axis. It is 
 used for transmitting motion from one shaft to another whose axes 
 are parallel. There is also a class of spur gears called herring bone 
 gears or double helical spur gears in which, while the axes are paral- 
 lel, the teeth are arranged spirally around the cylindrical surfaces of 
 the gears. 
 
 Bevel gears are gears used to transmit motion between shafts at 
 right angles to each other, the shafts being in the same plane. The 
 teeth of the gears must necessarily stand at an angle to the axis. 
 
 Miter gears are bevel gears whose teeth stand at an angle of 45 
 ■degrees to the axis and are used to transmit motion between shafts 
 at right angles, in which the number of revolutions of the two shafts 
 is the same. 
 
2-1 V GEARING 
 
 Angle gears are similar to bevel gears, except that while the shafts 
 intersect they are placed at some other angle to each other than 90 
 degrees. This angle may be either obtuse or acute. 
 
 A IiKiitiiig tooth gear is a gear into which an extra tooth has beeu 
 introduced so as to make the number of teeth in the gear and pinion 
 prime to each other so that any two teeth will not come in contact 
 until each tooth in the small gear has been in contact with every tooth 
 in the large gear. This tends to equalize wear on the gears. A hunt- 
 ing tooth may be introduced either into bevel or spur gears. 
 
 An internal gear is a spur gear having teeth on the inside of its 
 periphery in place of on the outside and the pinion or smaller gear is 
 situated inside of the large gear. In an internal gear the shapes of 
 the teeth correspond to the spaces in an ordinary spur gear of the 
 same pitch and diameter, with the exception of the fact that the back- 
 lash and clearance are reversed in position. 
 
 A rack is a straight bar having gear teeth formed upon it. It may 
 be considered as a gear of infinite radius. 
 
 When two gears act upon each other, the greater is termed the 
 gear and the less the pinion. 
 
 The word diameter when applied to gears is always understood 
 to mean the pitch diameter. The tooth curves are always developed 
 from the circle which represents the pitch diameter. 
 
 Circular pitch is the distance between corresponding points of 
 adjacent teeth measured along the pitch circle and is obtained by 
 dividing the length of the circumference of the pitch circle by the 
 number of teeth in the gear. 
 
 Diametral pitch is the number of teeth in a gear divided by the 
 number of inches in the diameter of the pitch circle. In other words, 
 it is the number of teeth per inch of the pitch diameter of the gear. 
 
 The thickness of a gear tooth is its thickness measured on a pitch 
 circle. 
 
 The space between two gear teeth is the space measured on the 
 pitch circle. 
 
 The addendum is that part of the tooth outside the pitch circle. 
 
 The dedendum, or root, is that part of the tooth inside the pitch 
 circle. 
 
 The hack-lash is the side clearance between the two teeth in mesh. 
 
 The clearance is space between the point of a tooth and the bot- 
 tom of the space into which the tooth meshes. 
 
 The face of a tooth is the working surface from the pitch circle 
 to the point of the tooth. 
 
SPUR GEARS 3-1 V 
 
 The flank of a tooth is the surface from the pitch circle to the 
 root of the tooth. 
 
 The length of a tooth is the distance from the root of the tooth 
 to its point. 
 
 The pitch point of a tooth curve is the point in which the outHne 
 of a tooth intersects the pitch circle. 
 
 When two gears are so located that their teeth run together, the 
 gears are said to be in mesh. 
 
 Rules 
 
 When the circular pitch is given to obtain the diametral pitch, 
 divide 3.1416 by the circular pitch. 
 
 When the diametral pitch is given to obtain the circular pitch, 
 ■divide 3.1416 by the diametral pitch. 
 
 When the number of teeth and the circular pitch are given to 
 obtain the pitch diameter, multiply the circular pitch by the number 
 cf teeth and divide the product by 3.1416. 
 
 When the number of teeth and the diametral pitch are given to 
 obtain the pitch diameter, divide the number of teeth by the diametral 
 pitch. 
 
 When the pitch diameter and the circular pitch are given to 
 obtain the circular pitch, multiply the pitch diameter by 3.1416 and 
 divide by the circular pitch. 
 
 When the pitch diameter and the diametral pitch are given to 
 obtain the number of teeth, multiply the pitch diameter by the dia- 
 metral pitch. 
 
 When the pitch diameter and the number of teeth are given to 
 obtain the circular pitch, multiply the pitch diameter by 3.1416 and 
 divide by the number of teeth. 
 
 When the pitch diameter and the number of teeth are given to 
 obtain the diametral pitch, divide the number of teeth by the pitch 
 diameter. 
 
 Involute Teeth 
 
 The involute curve is the curve which would be drawn by a 
 pencil point at the end of a thin band that will not stretch and is 
 drawn tight while being unwound from a cylinder. 
 
 The base circle in the involute system of gearing is the circle 
 from which the involute curve that forms the tooth outline is drawn. 
 The base circle is always inside of the pitch circle. The base circle 
 for the 15 degree involute tooth is inside the pitch circle a distance 
 equal to 1-60 of the pitch diameter, and the base circle for the 20 
 
4-IV 
 
 GEARING 
 
 degree involute tooth is inside of the pitch circle by a distance equal 
 to about 3-100 of the diameter of the pitch circle. 
 
 Fig. 1 shows the manner of developing or drawing the 15 degree 
 involute tooth curve. A is the pitch point of the pitch circle. The 
 line B-C is drawn at an angle of 15 degrees to a tangent to the pitch 
 circle at the pitch point. The base circle is then drawn tangent to 
 the line B-C. 
 
 Figr. 1. Development of 15° Involute Tooth \ 
 
 \ 
 
 The line B-C is called the line of action, as it is along this line 
 that the gear teeth will be in contact. In laying off a gear tooth any 
 convenient number of points may be stepped off between the pitch 
 point A and the point of tangency of the base circle G. With the 
 dividers set at the same distance succeeding points are stepped off along* 
 the base circle as shown at L, K, J, I, H, G, F, E, D, and S. Point S 
 is one point in the tooth curve. Tangents to the base circle should 
 then be drawn at the points D, E, F, H, I, J, K, and L and on these 
 tangents distances equal to the arcs which they correspond to should 
 be stepped off. This will give a series of points M, N, O, P, Q, etc., 
 which are points in the desired tooth outline. A smooth curve drawn 
 through these points will represent the outline of the tooth. 
 
 An approximate method of drawing a 20 degree involute curve 
 js shown in Fig. 2. This method can, however, be applied to any 
 ether degree of involute teeth equally well. The pitch circle should 
 be drawn first and spaced off to correspond with the pitch points. 
 One of the spaces should then be divided, giving the point O, which 
 
SPUR GEARS 
 
 5-IV 
 
 corresponds to the center of the tooth on the pitch circle. Through 
 this point draw a radial line and at right angles to it a tangent as 
 shown. From this tangent lay off an angle of 20 degrees and draw 
 the line A-B. Tangent to the line A-B draw the base circle. Also 
 draw the radial lines C, D and E through the pitch points of the 
 teeth. At the pitch point on the line C draw a tangent to the pitch 
 circle, lay off 20 degrees and draw the line F-G. In like manner from 
 the pitch point on the line D draw a tangent, lay off 20 degrees and 
 draw the line H-I and also from the pitch point on the line E draw 
 
 Fig. 2. Approximate Method of Drawing 20' Involute Tooth 
 
 a tangent, lay off 20 degrees and draw the line J-K. It will be noted 
 that all of these lines pass through a pitch point on the pitch circle 
 and hence are tangent to the base circle. The point L where the lines 
 F-G and H-I intersect will give a center for the flank radius to use 
 for drawing that portion of the tooth outline between the base circle 
 and the root, and the point M where the lines H-I and J-K intersect 
 will give the center for the face radius which is used in drawing the 
 portion of the tooth curve outside the base circle. The points L and 
 M will fall very close to the base circle, in fact, close enough so that 
 for all the teeth the centers may be taken on the base circle. By this 
 means, it will be noticed that, circular arcs of approximately the same 
 form as the involute curve have been substituted for it. 
 
 Drawing the Epicycloidal Curve 
 
 An epicycloid is a curve formed by a point on the circumference 
 of the circle as it is beine rolled on the outside of another circle, while 
 
6-IV 
 
 GEARING 
 
 a hypocycloid is a line generated by the point on the circumference 
 of a circle that is being rolled on the inside of another circle. 
 
 In the epicycloidal system of gearing the faces of the teeth are 
 formed of epicycloids and the flanks by hypocycloids, as shown in 
 Fio-. 3. The complete circles are not drawn in this case, but only short 
 arcs, though the centers for the circles are shown on the radial lines. 
 
 The circle rolled upon the other circle to generate the tooth 
 curve is called the circle of action or the generating circle and is 
 rolled upon the pitch circle. In laying off this tooth, the pitch circle, 
 addendum circle and root circle should be drawn first. The pitch 
 circle is then spaced off to correspond with the number of teeth desired. 
 
 Fig. 3. Drawing Epicycloidal Teeth 
 
 In order to lay off the tooth curves from the pitch point A step off 
 equal divisions on the pitch circle right and left as shown. Through 
 these points radial lines are drawn and from centers upon these radial 
 lines arcs of the circle of action are drawn as shown. In order to 
 determine the points of the tooth curves it is necessary to measure 
 off on these arcs of the generating circle distances corresponding to 
 the portion of the pitch circle which has been rolled over between the 
 point A and the point where the radial line intersects the pitch circle. 
 For instance, to find the point Z, step off the distance from A to K 
 upon the pitch circle with a pair of dividers. Then step off cor- 
 responding distances along the generating circle from K to Z, thus 
 obtaining the point Z. The point Y is obtained by stepping off the 
 distances from A to J and back along the generating circle to Y. 
 X and W are obtained in like manner and the points V, U, T, S, and 
 
SPUR GEARS 
 
 7-IV 
 
 R of the flank curve are in like manner obtained by stepping off dis- 
 tances from the pitch circle to radial lines at B, C, D, E, F, and G and 
 then back along the generating circles to points V, U, T, S and R. 
 After the points are obtained a smooth curve is drawn through them 
 Avhich will represent the desired tooth curve. 
 
 Involute Odontograph Table 
 
 In practice these theoretical curves are rarely laid out, approxima- 
 tions being used which are obtained by means of circular arcs. The 
 radii for these circular arcs are commonly obtained from odontograph 
 
 GRANT'S INVOLUTE ODONTOGRAPH 
 
 STANDARD INTERCHANGEABLE TOOTH, CENTERS ON BASE WNE 
 
 
 Divide by the Diametrical Pitch 
 
 Multiply by the Circular Pitch 
 
 Teeth 
 
 F. 
 
 G. 
 
 F. 
 
 G. 
 
 
 Face Radius 
 
 Flank Radius 
 
 Face Radius 
 
 Flank Radius 
 
 • 10 
 
 2.28 
 
 .69 
 
 .73 
 
 .22 
 
 11 
 
 2.40 
 
 .83 
 
 .76 
 
 .27 
 
 12 
 
 2.51 
 
 .96 
 
 .80 
 
 .31 
 
 13 
 
 2.62 
 
 1.09 
 
 .83 
 
 .34 
 
 14 
 
 2.72 
 
 1.22 
 
 .87 
 
 .39 
 
 15 
 
 2.82 
 
 1.34 
 
 .90 
 
 .43 
 
 16 
 
 2.92 
 
 1.46 
 
 .93 
 
 .47 
 
 17 
 
 3.02 
 
 1.58 
 
 .96 
 
 .50 
 
 18 
 
 3.12 
 
 1.69 
 
 .99 
 
 .54 
 
 19 
 
 3.22 
 
 1.79 
 
 1.03 
 
 .57 
 
 20 
 
 3 32 
 
 1.89 
 
 1.06 
 
 .60 
 
 21 
 
 3.41 
 
 198 
 
 1.09 
 
 .63 
 
 22 
 
 3 49 
 
 2.06 
 
 1 11 
 
 .66 
 
 23 
 
 3. 57 
 
 2.15 
 
 1.13 
 
 .69 
 
 24 
 
 3.64 
 
 2.24 
 
 1.16 
 
 .71 
 
 25 
 
 3.71 
 
 2.33 
 
 1.18 
 
 .74 
 
 26 
 
 3.78 
 
 2.42 
 
 1 20 
 
 .77 
 
 27 
 
 3.85 
 
 2.50 
 
 1.23 
 
 .80 
 
 28 
 
 3 92 
 
 2.59 
 
 1.25 
 
 .82 
 
 29 
 
 3.99 
 
 2 67 
 
 1.27 
 
 .85 
 
 30 
 
 4.06 
 
 2.76 
 
 1.29 
 
 .88 
 
 31 
 
 4.13 
 
 2.85 
 
 1.31 
 
 .91 
 
 32 
 
 4.20 
 
 2.93 
 
 1.34 
 
 .93 
 
 33 
 
 4.27 
 
 3.01 
 
 1.36 
 
 .96 
 
 34 
 
 4.33 
 
 3.09 
 
 1.38 
 
 .99 
 
 35 
 
 4 39 
 
 3.16 
 
 1.39 
 
 1.01 
 
 36 
 
 4.45 
 
 3 23 
 
 1.41 
 
 1.03 
 
 37—40 
 
 4 20 
 
 1.34 
 
 41—45 
 
 4.63 
 
 1.48 
 
 46-51 
 
 5.06 
 
 1.61 
 
 52—60 
 
 5.74 
 
 1.83 
 
 61—70 
 
 6.52 
 
 2.07 
 
 71-90 
 
 7.72 
 
 2 46 
 
 91—120 
 
 9.78 
 
 3.11 
 
 121—180 
 
 13.38 
 
 4.26 
 
 181—360 
 
 21.62 
 
 6.88 
 
 Draw the rack tooth by the special method. 
 
 — [From Grant's Treatise on Gear Wheels. 
 
8-IV 
 
 GEARING 
 
 tables. In Grant's work on Gearing, he gives an involute odonto- 
 graph table from which radii for various sizes of gears can be obtained. 
 Fig. 4 illustrates a method of laying out an involute tooth by means 
 of this odontograph table. 
 
 The pitch circle or pitch line should be drawn first and the adden- 
 dum line drawn outside the pitch line at a distance from it equal to 
 one divided by the diametral pitch or to 1-3 of the circular pitch. The 
 dedendum line should be drawn inside the pitch circle the same dis- 
 tance, but in practice this is not used, the root line being inside of the 
 pitch line by a distance equal to 9-8 of the addendum. 
 
SPUR GEARS 
 
 9-IV 
 
 The base line is drawn inside the pitch Hne by a distance of 1-60 
 of the pitch diameter. To draw a gear proceed as follows : The 
 figure shows several teeth of a gear having 21 teeth 11.74 inches pitch 
 diameter and 1}^ inches circular pitch. The gear is also shown in 
 contact with the rack. After the various circles have been drawn the 
 pitch circle should be spaced for the pitch points by stepping off with 
 a pair of dividers or any other convenient method. 
 
 In the Odontograph table opposite the 21 teeth and under the face 
 radius is found the number 1.09. This must be multiplied by the 
 circular pitch of the gear and gives 1.907. With the dividers set to 
 this face radius of 1.907 draw the face of the teeth from the addendum 
 to the pitch circle, keeping one point of the dividers on the base line as 
 3 center. If the number of teeth is greater than 36 or if the pitch is 
 small, this face radius should be extended to the base line. In the 
 case under consideration opposite 21 teeth in the table and in the 
 column headed Flank Radius is found the figure .63 and this multi- 
 plied by the circular pitch gives 1.102. With the dividers set to this 
 
 GRANT'S EPICYCLOIDAL ODONTOGRAPH 
 
 STANDARD CYCLOIDAI, TEETH — INTERCHANGEABI,E SERIES 
 
 From a Ptmon of Ten Teeth to a Rack 
 
 
 t OF TEETH 
 
 Fo 
 For 
 
 r one D 
 
 ametrical P 
 
 tch 
 le by 
 
 For One 
 
 [nch Circular 
 
 Pitch 
 
 NUMBEl 
 
 any other pitch divic 
 
 For any bth 
 
 er pitch mu 
 
 tiply by 
 
 IN TI 
 
 IE GEAR 
 
 that pitch 
 
 
 
 hat pitch 
 
 
 
 Faces 
 
 Flani 
 
 s 
 
 Faces 
 
 Flanks 
 
 Exact 
 
 Intervals 
 
 Rad. 
 
 Dis. 
 
 Rad. 
 
 Dis. 
 
 Rad. 
 
 Dis. 
 
 Rad. 
 
 Dis. 
 
 10 
 
 10 
 
 1.99 
 
 .02 
 
 —8.00 
 
 4.00 
 
 .62 
 
 .01 
 
 —2.55 
 
 1.27 
 
 11 
 
 11 
 
 2.00 
 
 .04 
 
 -11.05 
 
 6.50 
 
 .63 
 
 .01 
 
 —3.34 
 
 2.07 
 
 12 
 
 12 
 
 2.01 
 
 .06 
 
 QO 
 
 QO 
 
 •64 
 
 .02 
 
 00 
 
 CO 
 
 liVz 
 
 13—14 
 
 2.04 
 
 .07 
 
 14.50 
 
 9.43 
 
 .65 
 
 .02 
 
 4.60 
 
 3.00 
 
 15>4 
 
 15-16 
 
 2.10 
 
 .09 
 
 7.86 
 
 3.46 
 
 .67 
 
 .03 
 
 2.50 
 
 1.10 
 
 nyi 
 
 17—18 
 
 2.14 
 
 .11 
 
 6.13 
 
 2.20 
 
 .68 
 
 .04 
 
 1.95 
 
 .70 
 
 20 
 
 19-21 
 
 2.20 
 
 .13 
 
 5.12 
 
 1.57 
 
 .70 
 
 .04 
 
 1.63 
 
 .50 
 
 23 
 
 22—24 
 
 2.26 
 
 .15 
 
 4.50 
 
 1.13 
 
 .72 
 
 .05 
 
 1.43 
 
 .36 
 
 27 
 
 25—29 
 
 2.33 
 
 .16 
 
 4.10 
 
 .96 
 
 .74 
 
 .05 
 
 1.30 
 
 .29 
 
 33 
 
 30—36 
 
 2.40 
 
 .19 
 
 3.80 
 
 .72 
 
 .76 
 
 .06 
 
 1.20 
 
 .23 
 
 42 
 
 37—48 
 
 2.48 
 
 .22 
 
 3.52 
 
 .63 
 
 .79 
 
 .07 
 
 1.12 
 
 .20 
 
 58 
 
 49—72 
 
 2.60 
 
 .25 
 
 3.33 
 
 .54 
 
 .83 
 
 .08 
 
 1.06 
 
 .17 
 
 97 
 
 73-144 
 
 2.83 
 
 .28 
 
 3.14 
 
 .44 
 
 .90 
 
 .09 
 
 1.00 
 
 .14 
 
 290 
 
 145—300 
 
 2.92 
 
 .31 
 
 3.00 
 
 .38 
 
 .93 
 
 .10 
 
 .95 
 
 .12 
 
 oo 
 
 Rack 
 
 2.96 
 
 .34 
 
 2,96 
 
 .34 
 
 .94 
 
 .11 
 
 .94 
 
 .11 
 
 The table gives the distances and radii if the pitch is either exactly one diametral or one inch 
 circular and for any other pitch multiply or divide as directed in the table. 
 
 — [From Grant's Treatise on Gear Wheels 
 
10-IV 
 
 GEARING 
 
 radius and the center on the base circle, draw the flanks of the teeth 
 from tlie pitch circle to the base circle. From the base circle con- 
 tinue the flanks of the teeth to the root circle by straight radial liner> 
 and round the roots of the teeth with a fillet. 
 
 To lay ofif the rack teeth it is first necessary to draw a straight 
 line for the pitch line and two parallel lines for the addendum and 
 root lines. The sides of the teeth are drawn through the pitch points 
 at an angle of 15 degrees from the perpendicular, as shown in Fig. 4. 
 
 The point of the tooth from the point A Fig. 4 to L> must be 
 rounded by an arc drawn from a center on the pitch line and with 
 the dividers set to a radius equal to 2.10 inches divided by the diametral 
 pitch or the circular pitch multiplied by .67. In the case imder con- 
 sideration multiplying .67 by the circular pitch we obtain 1.17 as the 
 radius to be used. 
 
 Epicycloidal Odontograph Tables 
 
 Grant has also gotten up an Odontograph table giving the pro- 
 portions of epicycloidal teeth. To apply this table in laying out the 
 gear shown in Fig. 5 we will proceed as follows : 
 
 Fisr 5. Laying Out an Epicycloidal Gear by the Odontograph Table 
 
 The gear has 21 teeth, 11.74 inches pitch diameter and l-)4 inches 
 circular pitch. The pitch circle, addendum and root circles should 
 be drawn. The pitch points should also be marked on the pitch circle. 
 
 In the Odontograph table we find opposite 21 under the head of 
 circular pitch and the faces of the teeth. .04 as the factor for obtain- 
 ing the distance of the circle of centers from the pitch circle. Multi- 
 plying the circular pitch by this we have .07 and hence we must lay 
 off a circle at this distance inside Ihe pitch circle. 
 
SPUR GEARS 
 
 11-IV 
 
 The flank center distance for 21 teeth is .5 and multiplying this by 
 the circular pitch we have .875 as the distance between the pitch circle 
 and the line of centers for the flanks. This circle should be drawn 
 as shown in Figf. 5. From the table we find that the factor for the 
 
 GRANT'S INVOLUTE GEAR TEETH PROPORTIONS 
 
 Circular 
 Pitch. 
 
 A 
 
 B 
 
 C 
 
 E 
 
 H 
 
 c- 
 
 1 
 
 .33 
 
 .04 
 
 .49 
 
 .08 
 
 .67 
 
 .475 
 
 lys 
 
 .37 
 
 .04 
 
 .55 
 
 .08 
 
 .75 
 
 .534 
 
 1^ 
 
 .41 
 
 .05 
 
 .61 
 
 .10 
 
 .83 
 
 .594 
 
 iy$ 
 
 .45 
 
 .05 
 
 .67 
 
 .10 
 
 .91 
 
 .653 
 
 1/2 
 
 .50 
 
 .06 
 
 .73 
 
 .12 
 
 1.00 
 
 .712 
 
 IK 
 
 .58 
 
 .07 
 
 .85 
 
 .14 
 
 1.17 
 
 .831 
 
 2 
 
 .66 
 
 .08 
 
 .98 
 
 .16 
 
 1.34 
 
 .950 
 
 2% 
 
 .75 
 
 .09 
 
 1.10 
 
 .18 
 
 1.50 
 
 1.07 
 
 2% 
 
 .83 
 
 .10 
 
 1.22 
 
 .20 
 
 1.67 
 
 1.19 
 
 IK 
 
 .91 
 
 .11 
 
 1.34 
 
 .22 
 
 1.84 
 
 1.31 
 
 3 
 
 1.00 
 
 .12 
 
 1.47 
 
 .24 
 
 2.01 
 
 1.43 
 
 3^ 
 
 1.08 
 
 .13 
 
 1.59 
 
 .26 
 
 2.17 
 
 1.54 
 
 iV^ 
 
 1.16 
 
 .14 
 
 1.71 
 
 .28 
 
 2.34 
 
 1.66 
 
 3K 
 
 1.25 
 
 .15 
 
 1.83 
 
 .30 
 
 2.51 
 
 1.78 
 
 4 
 
 1.33 
 
 .16 
 
 1.96 
 
 .32 
 
 2.68 
 
 1.90 
 
 4X 
 
 1.41 
 
 .17 
 
 2.08 
 
 .34 
 
 2.84 
 
 2.02 
 
 4K 
 
 1.50 
 
 .18 
 
 2.20 
 
 .36 
 
 3.01 
 
 2.14 
 
 4K 
 
 1.58 
 
 .19 
 
 2.32 
 
 .38 
 
 3.18 
 
 2.25 
 
 5 
 
 1.66 
 
 .20 
 
 2.45 
 
 .40 
 
 3.35 
 
 2.37 
 
 5K 
 
 1.75 
 
 .21 
 
 2.57 
 
 .42 
 
 3.51 
 
 2.49 
 
 5'A 
 
 1.83 
 
 .22 
 
 2.69 
 
 .44 
 
 3.68 
 
 2.61 
 
 5K 
 
 1.91 
 
 .23 
 
 2.81 
 
 .46 
 
 3.85 
 
 2.73 
 
 6 
 
 2.00 
 
 .25 
 
 2.94 
 
 .50 
 
 4.02 
 
 2.85 
 
 6^^ 
 
 2.16 
 
 .27 
 
 3.18 
 
 .54 
 
 4.35 
 
 3.09 
 
 7 
 
 2.33 
 
 .29 
 
 3.43 
 
 .58 
 
 4.69 
 
 3.33 
 
 7/2 
 
 2.50 
 
 .31 
 
 3.67 
 
 .62 
 
 5.02 
 
 3.56 
 
 8 
 
 2.66 
 
 .33 
 
 3.92 
 
 .66 
 
 5.36 
 
 3.80 
 
 8J^ 
 
 2.83 
 
 .35 
 
 4.16 
 
 .70 
 
 5.69 
 
 4.04 
 
 9 
 
 3.00 
 
 .37 
 
 4.41 
 
 .74 
 
 6.03 
 
 4.28 
 
 9/2 
 
 3.16 
 
 .39 
 
 4.65 
 
 .78 
 
 6.36 
 
 4.51 
 
 10 
 
 3.33 
 
 .41 
 
 4.90 
 
 .82 
 
 6.70 
 
 4.75 
 
 D or distance to the base line equals b's of pitch diameter. 
 Note,— Column C is for cast gears. 
 
12-IV 
 
 GEARING 
 
 face radius of the 21 teeth is .70. then multiplying the circular pitch 
 by this factor we have 1.22. With the dividers set to this radius and 
 keeping one point on the circle of face centers the faces of all the teeth 
 should be drawn. From the table we find that the factor for the radius 
 
 Cleg 
 
 Fillet 
 
 Addemlum- 
 
 — DedeTVlum or root 
 
 — Height of tooth 
 -Thickness of iooth- 
 
 — Width of space - 
 
 Fig. f>. Diagram for Tooth Parts 
 
 of the flanks of the teeth corresponding to 21 teeth is 1.63 and multi- 
 plying the circular pitch by this we have 2.85. With the dividers set 
 to this radius and one point on the circle of flank centers, we should 
 draw the flanks of the teeth. Small fillets should then be drawn at the 
 base of each tooth, thus completing the tooth outline. 
 
SPUR GEARS 
 
 13-IV 
 
 Proportions of Tooth Parts 
 
 Grant has gotten up a table of proportions of tooth parts for use 
 in connection with his invokite odontograph. For convenience, how- 
 ever, in obtaining this information quickly for different pitches, a dia- 
 gram like that shown in Fig. 6 may be used. This diagram is for the 
 extra short involute tooth and gives proportions of teeth from yl inch 
 to 6 inches circular pitch. Such a diagram can be made for teeth of 
 
 Fig-. 7. Jig for Plain Spur Involute Gear 
 
 any proportions, and will be found a great time saver on account of 
 the fact that its use reduces the calculations necessary. 
 
 In laying out such a diagram A-B represents the greatest pitch 
 required, in this case six inches. The perpendicular B-C is used for 
 laying off the various proportions for six inch circular pitch. After 
 these points are laid off they are connected with the point A by a 
 series of diagonal lines. In order to obtain the proportions for any 
 other tooth it is only necessary to erect a perpendicular at a distance 
 from A corresponding to the circular pitch desired. In the illustra- 
 tion perpendiculars have been drawn corresponding to all circular 
 pitches between %. inch and 6 inches, varying by quarters of an inch. 
 
 Fig, 8. Jig for Involute Bevel Gear 
 
 The proportions of this short involute tooth are as follows: Adden- 
 dum equals 2-10 circular pitch. Dedendum equals 2-10 circular pitch. 
 Clearance equals 5-100 circular pitch, plus one. The thickness of the 
 tooth equals 47-100 of the circular pitch. 
 
 Tooth Jigs 
 
 In place of having to lay off the tooth curves or outlines on each 
 individual tooth it is best to make a hard wood jig of the exact out- 
 line of the tooth and use it in forming all of the other teeth. Fig. 7 
 ^hows such a jig for a plain spur involute gear and Fig. 8 such a jig 
 for an involute bevel gear. It will be noticed that the jig is cut down 
 
14-IV 
 
 GEARING 
 
 or relieved for a short distance each side of the space which is to 
 receive the block for the gear tooth. The opening in the jig to receive 
 the block should be the exact length of the teeth across the face of the 
 wheel and the blocks trimmed to fit snugly and then secured with 
 screws as shown. 
 
 After the block is secured in the jig, a plane may be clamped 
 in the vise as shown in Figs. 9 and 10. Blocks should be clamped to 
 
 Fig. 9. Side View of Plane Clamped to Cut Teeth 
 
 this plane at such points that the blades of the plane cannot cut the 
 face of the jig. It is on this account that the clearance is provided 
 in the face of the jig at each end of the tooth block. Fig. 10 shows 
 an end view of the block and plane with the stops removed so as to 
 show the dififerent positions assumed by the jig in working out an 
 involute tooth. In working out an involute tooth a plane having a 
 
 Fig. 10. End Mew of Plane Clamped to Cut Teeth 
 
 flat face may be used and it is well to make a special plane with a long 
 sole so that it will not be necessary to use blocks to piece it out when 
 working long teeth. 
 
 When working out epicycloidal teeth it is necessary to use a 
 plane having a curved face as shown in Fig. 11, and also to use a 
 block or stop on the side of the plane as shown. The curve of the 
 face of the plane should be of less radius than the curve of the flanks 
 of the teeth. 
 
SPUR GEARS 
 
 15-IV 
 
 In laying out the wooden block for the spur tooth jig the device 
 shown in Fig. 12 will be found very handy for laying off the tooth 
 curves. In the device shown the jig for a 16-tooth pinion is being 
 laid out. A board shown at A is taken and a slot cut in one end that 
 will just fit the jig block. The jig block is placed in position as shown 
 with one end flush with the face of the board. The tooth is then 
 laid off. After this the jig is removed and placed other end to in the 
 slot, when the same centers can be used in laying ofif the tooth outline. 
 This insures an accurate layout on both ends of the block and brings 
 the layout on the two ends in line. 
 
 Jig Slock 
 
 A 
 
 Fig. 12. Rig for Laying Off Tooth Jig 
 
 Fig. 11. Plane with Curved Face 
 for Epicycloidal Gear 
 
 After the teeth for the spur gear have been planed out in jigs, 
 they can be tested by placing two of them end to end and seeing if they 
 coincide, then reversing both teeth and placing the opposite ends in 
 contact. If there is any error in the teeth it will be doubled by this 
 method. Care should be taken to have the bottom of both blocks 
 planed free from wind and to fit accurately on the outside of the 
 cylindrical portion of the pattern. 
 
 Construction of Gear Patterns 
 
 The general method of constructing or building up a gear pattern 
 is shown in Fig. 13. The rim should be built up and turned in the 
 usual manner with just perceptible draft in the outer diameter. The 
 
16-IV 
 
 GEARING 
 
 number of teeth should be spaced off before it is removed from the 
 lathe. If there is a surface plate available the rim should be laid 
 on it and, with the try square, lines drawn across the face correspond- 
 ing to the spacing done in the lathe. Placing the try square against 
 the rim of the gear is not always a reliable method. 
 
 Fig. 14 shows a common manner of setting the arms together. 
 This work can be done very handily on the ordinary bench saw. After 
 the arms have been put together, they should be let into the rim as 
 shown in Fig. 13 and secured with glue and dowel pins. A more sub- 
 stantial manner of securing the arms in place is to build them into the 
 rim during its construction. 
 
SPUR GEARS 
 
 17-IV 
 
 After the teeth have all been jigged out or sanded to form, in the 
 manner to be described .later, they should be placed on the rim, the 
 root of each tooth being set with its edge in contact with one of 
 the spacing lines drawn on the face of the rim. This is a very 
 much more accurate method than attempting to space the teeth to a 
 
 x£: 
 
 ' ' 
 
 j_r 
 
 Fig. 14. Method of Setting Gear Arms Together 
 
 center line. Each tooth should be glued in place and rubbed down 
 so that it fits the line accurately and then, after the glue has set 
 slightly, nailed in position. As the work proceeds the teeth should 
 be tested with the square and calipers and the work finished by rubbing 
 in a leather fillet. 
 
18-1 V GEARING 
 
 CHAPTER II 
 
 BEVEL AND WORM GEAR PATTERNS 
 
 Bevel Gears 
 
 In the last chapter the making of spur gear patterns and the 
 method of jigging teeth for spur or bevel gear patterns was described. 
 In this chapter will be described one or two methods of making 
 bevel and worm gear patterns which have proven very satisfactory 
 in practice. 
 
 The rim of a bevel gear should be built up of segments in a man- 
 ner similar to the method used in building the rim of a spur gear, 
 except that, owing to the conical form of the rim no two series of 
 segments are of the same diameter. Fig. 15 shows the iron faceplate 
 
 Fig. 15. Segments for Bevel Gear Pattern on Face Plate 
 
 of the lathe with a large wooden faceplate B attached to it and the 
 section of the rim of a gear built up of four courses of segments as 
 shown at A. 
 
 The outline of the rim is drawn on the segments showing the 
 amount of stock to be turned off in finishing this portion of the pat- 
 tern. After the rim is built up and attached to the faceplate the inside 
 surface should be turned and a chuck should then be attached to the 
 faceplate B, turned up to fit the inside of the rim, the rim secured to 
 the chuck and the outside or face turned ready to receive the teeth. 
 
 It is best to space off the teeth before removing the rim from the 
 lathe. Spaces corresponding to the number of teeth should be stepped 
 off on the face near the outer diameter. Next attach a block to the 
 center of the faceplate, which will project far enough to contain the 
 apex of the cone of which the rim is the frustrum. This block is 
 shown at A, Fig. 16. The point of the block should be turned so that 
 it will form a portion of the surface of the cone, of which the rim 
 is a portion. 
 
 Next, take a long lathe rest as shown at D and adjust it so that 
 its upper edge is level and on a line with the point or apex of the 
 
BEVEL GEARS 
 
 19-IV 
 
 cone. If the lathe rest is not long enough a straight edge can be 
 attached to it. 
 
 After the rest or straight edge has been adjusted lines can be 
 drawn on the face of the gear through the points stepped off near its 
 
 Fig. 16. Face Plate with Blocks at Center of Gear to Form .Apex of Cone 
 
 outer circumference, as shown in Fig. 16. These lines would all 
 intersect at the apex of the cone. 
 
 The teeth can then be formed by jigging, as described in the 
 
 Fig. 17. Gear with Part of the Teeth Attached and Arms Fitted 
 
 previous chapter, or by sanding, and attached to the face of the gear 
 as shown in Fig. 17. 
 
 While attaching the teeth the work should be removed from the 
 lathe, but the gear should not be removed from the faceplate. The 
 
20-IV 
 
 GEARING 
 
 root of each tooth should be set to one of the radial lines and the teeth 
 should be tried with calipers and with the straight edge from the 
 apex of the cone, as located on the post attached to the center of the 
 faceplate. It will be found convenient to drive a small pin or brad 
 into the apex to assist in this work. The arms of the gear should be 
 
 laid out and set in as shown in Fig. 17. At A is shown a section of 
 
 the rim and at B the manner in which the end of the arm joins the rim. 
 
 The method of developing the outline for the tooth at the outside 
 
 and inside faces of the gear, also at the outer and inner ends of the 
 
BEVEL GEARS 21-IV 
 
 jig is shown in Fig. 18. The work is laid out for a gear having a 
 pitch radius of 12 3-32 inches, 38 teeth, 2-inch circular pitch and a 
 5-inch face. 
 
 The number of teeth in a bevel gear is the number upon the work- 
 ing pitch diameter or radius C-D, but this number is not used in lay- 
 ing out the tooth outline. In developing the curves for the tooth, 
 the number of teeth in a gear of corresponding pitch and having a 
 pitch radius equal to the back conical radius or B-E in Fig. 18 is used. 
 In order to lay out the teeth it is first necessary to draw a section of 
 one-half of the gear as shown in Fig. 18, the pitch radius of the gear 
 being C-D and the face conical radius A-B. 
 
 Next draw a line perpendicular to A-B from a point on the pitch 
 line of the gear which is on the line passing through D and at a dis- 
 tance from the axis equal to the pitch radius C-D. This line will 
 intersect the center line of the gear at the point E, thus giving the 
 back pitch radius B-E. Lay off the height or length of the tooth Z, 
 and draw radial lines extending beyond the ends of the teeth. 
 
 The spaces X-X correspond to the portions of the jig at each end 
 of the tooth and it will be necessary to determine the outline of the 
 tooth for both the outer and inner ends of the jig, as well as for the 
 outer and inner ends of the face of the tooth proper. With A as a 
 center and the radius A-B scribe an arc of a circle and space off several 
 teeth with the given circular pitch, lay off the thickness of the tooth 
 W and draw radial lines through these points. This will give the 
 thickness of the tooth and the circular pitch at the ends of the jig and 
 at the smaller end of the tooth. 
 
 It should be noted that all lines on the face of the tooth whether 
 at the top, bottom, or any point on the side, including the base line, all 
 meet in the apex A. 
 
 With E as a center and B-E as a pitch radius, draw the pitch line, 
 and set off several teeth with the given circular pitch. Lay off the 
 thickness of the teeth on this pitch line and draw in the addendum, 
 root and base circles, the whole to be calculated as explained in the 
 previous chapter. 
 
 As the tooth outline is taken from the back conical radius, it 
 should be calculated as follows : In the case in hand the radius B-E 
 equals 28.61, multiplying this by 2 equals 57.22 inches, as the diameter. 
 Multiplying this diameter by 3.1416 equals 179.76 inches, as the cir- 
 cumference of the pitch circle used in determining the form of the 
 tooth. Dividing this circumference by 2, the circular pitch gives 89.8 
 teeth. It should be noted that in dividing the circumference of this 
 construction pitch circle, the result will rarely be a whole number. 
 
22-1 V GEARING 
 
 hence the nearest whole number is taken as the number of teeth. In 
 this case 90 should be taken and we would look in the Odontograph 
 table opposite this number of teeth for the factors to be used in draw- 
 ing the tooth outline. From the Odontograph table the radius to be 
 used in drawing the face of the teeth should be found and the centers 
 O-O determined. With pitch radius equal to the lines F, G, and FI, 
 and E as a center, draw pitch circles for the outer end of the jig, 
 inner end of the tooth and inner end of the jig, as shown in Fig. 18. 
 Next draw the radial lines I-I through the points O-O which will 
 determine the centers to be used in drawing the face of the teeth cor- 
 responding to each of these different radii. Of course the addendum, 
 root and base circles would be drawn in in each case in their proper 
 relationship to the pitch circle. 
 
 When the gear is so large that it is not convenient to determine 
 the length of the back radius by a lay out for the large and small ends 
 of the tooth and jig, these radii can be calculated in the following 
 manner: If it is desired to calculate the back radius B-E correspond- 
 ing to a gear having the pitch radius C-D, we would first subtract from 
 90 degrees or the angle formed by the intersection of the back radius 
 B-E with the face radius A-B, the angle formed between A-B and the 
 center line of the gear, which in this case is 65 degrees ; 65 degrees 
 taken from 90 degrees will leave an angle of 25 degrees as the angle 
 between the radius B-E and the center line of the gear. 
 
 From a table of natural signs take the sign of 25 degrees, w^hich 
 is .42262, divide the working pitch radius C-D by this decimal, which 
 will give the length of the back radius B-E equal to 28.61 inches. 
 
 Having obtained this radius, calculations are next made for the 
 outline of the tooth at the large end as already explained. The outline 
 of the tooth at any other point or at the ends of the jig can be calculated 
 in the same way. 
 
 In all the calculations for the length of the back radius and the 
 outline of the tooth at the ends of the jig it should be borne in mind 
 that the number of teeth in any given bevel gear remains the same, no 
 matter what radius is used. 
 
 Double Helical Gears 
 
 For heavy mill work double helical gears of the form shown in 
 Fig. 19 are frequently used. Considerable care is necessary in making 
 the pattern for this class of gear, on account of the fact that the two 
 halves of the pattern must be screwed from the sand and any irregular- 
 ity in the teeth or body will cause trouble in the molding beside making 
 the gears run poorly on account of the fact that if the teeth are not 
 
BEVEL GEARS 
 
 23-IV 
 
 regular the gears will not mesh correctly. The profile of the teeth 
 remains the same as in an ordinary spur gear and is laid out from 
 the Odontograph tables. 
 
 In building such a gear as this the cylinder or body is built up 
 of segments with an off-set parting line as shown by the dotted lines 
 in Fig. 19 (A). This off-set or projection turned on the parting line 
 is for the purpose of centering the two halves of the pattern in 
 relation to each other. 
 
 Fig. 19. Double Helical Gear 
 
 After the body of the gear is completed, the number of teeth 
 should be laid off on the outer edge and also on the inner edge or 
 parting, taking care to allow the proper pitch or angle of tooth, which 
 is usually 30 degrees. To dress the inner face of the blocks so 
 that they will fit the tooth the device shown in Fig. 19 (C) may be 
 used. This consists of a box composed of sides E and F and ends G 
 ?nd H. The block J for the tooth is secured to the ends G and H by 
 screws as shown and then the inner face of the block is worked off 
 to the curve K. The blocks are left high enough to allow the outer 
 diameter to be trimmed slightly after they are in place. 
 
 After the blocks have been fitted to the rim they should be 
 secured with dowel pins and screws and then the gear with the tooth 
 blocks in place should be returned to the lathe and turned to the exact 
 diameter of the points of the teeth. 
 
 From the center of the cylinder or body to the outside diameter of 
 the blocks scribe radial lines passing through points stepped off' to cor- 
 respond with the number of teeth and with a metal templet cut from 
 a piece of sheet steel or zinc, scribe the profile of the teeth on the outer 
 and inner end of each block. Remove the blocks from the gear and 
 with a flexible rule draw lines from the points corresponding to the root 
 and top of the teeth as shown in Fig. 19 (D). Next dress the tooth 
 to shape, using the templet to determine the form of the tooth at any 
 
24-1 V 
 
 GEARING 
 
 point, the templet being guided by the Unes corresponding to the point 
 and root of the tooth. The teeth should now be placed back in position 
 and secured to the body with screws and dowel pins, but not with glue. 
 Then rub in leather fillets. When both parts of the pattern are com- 
 pleted they can be placed together and one revolved on the other. If 
 the teeth are perfect, they will match at any point. Fig. 19 (A) shows 
 a front elevation of the gear and (B) an end view. 
 
 Worm and Worm Gear Patterns 
 
 A right hand single threaded worm and gear are shown in Fig. 20. 
 The worm was laid out for a 6-inch pitch diameter to mesh with a 
 
 Section ( 
 Rim of Wheel 
 
 30.55"Pitch dia. 
 
 2 Pitch 
 
 18 Teeth 
 
 l)4"width of face 
 
 Fig. 20. Right Hand Single Threaded Worm and Gear 
 
 wheel of 30.55 inches pitch diameter and 2 inches circular pitch. The 
 worm wheel contains 48 teeth and has an extreme face width of 4^^ 
 inches. The shape of the worm wheel tooth is taken from Grant's 
 Odontograph for involute gear teeth. The usual length of tooth for 
 this class of gear is 6-10 circular pitch, the addendum being equal to 
 275-1000 and the dedendum to 325-1000 of the circular pitch. 
 
 As in practice the worm pattern is usually required to doctor the 
 teeth of the worm wheel for clearance it should be made first. The 
 pattern is parted longitudinally and is made as follows : Glue up the 
 stock and turn the outside diameter with the core prints attached. Do 
 not destroy the centers used in turning, as after the thread is cut the 
 pattern can be returned to the lathe and revolved at a slow speed while 
 the threads are sand papered. 
 
 When the pattern has been turned to the proper diameter and 
 length, wrap a piece of drawing paper around it and cut the exact 
 length and circumference. Place the paper on a board and lay ofif space 
 on each end equal to the circular pitch as shown in Fig. 21. If the 
 worm is to be single threaded, draw diagonal lines as shown by the full 
 lines. These will represent the pitch of the worm. If the worm is to be 
 
BEVEL GEARS 
 
 25-IV 
 
 double threaded, draw diagonal lines as represented by the dotted lines, 
 each line rising two divisions. If it is to be triple threaded, each line 
 should rise three divisions, and so on for any number of threads, the 
 angle increasing until the number of threads is so great and the angle 
 so steep that we cease to call it a worm and term it a spiral gear. 
 If the worm were to be left hand the diagonal lines would rise to the 
 left in place of to the right as shown. 
 
 Fifr. 21. Paper Template for Worm 
 
 If the drawing has been done correctly, when the paper is returned 
 to the pattern the point 1 will meet point 2, point 4 will meet point 3, 
 point 5 will meet point 6, and so on, thus forming a continuous spiral 
 line about the pattern. 
 
 After the paper has been returned to the pattern a tracing wheel or 
 some sharp pointed instrument should be used to prick the outline 
 of the thread through the paper upon the pattern. The paper should 
 
 CORE PRINT 
 
 CORE PRINT 
 
 Fig. 22. Stock Glued Up for Worm Gear 
 
 then be removed and the outline marked in with a pencil. The paper 
 may be attached to the pattern either by thumb tacks or by a few spots 
 of glue while pricking the outline through on to the pattern. Do not 
 cover the entire surface of the paper with glue as the paper would 
 stretch and the pitch of the thread be altered. 
 
 The outline or cross section of the worm thread is the same as the 
 outline of an involute rack tooth and hence has straight sides, as shown 
 in Fig. 20. 
 
 The roughing out of the thread can be done quite closely by clamp- 
 ing strips of wood to the sides of a back saw, so as to give the desired 
 
26-IV 
 
 GEARING 
 
 depth, and then sawing down on the line already laid out. Or the out- 
 line niav be formed by revolving the pattern in a V block placed over 
 the circular saw. 
 
 After the worm pattern is completed, the stock for the worm gear 
 should be glued up and the rim turned to the proper form as shown 
 in Fig. 22. The arms should be set in as in spur gears. 
 
 Worm gear teeth may be molded in cores or by parting the pattern 
 through the center and screwing each half of it out of the sand. The 
 former method the author considers somewhat simpler and hence has 
 illustrated it. For this reason the outer face of the pattern is turned 
 
 -ANGLE OF ROOT OF TOOTH 
 -ANGLE OF PITCH DIA. 
 -ANGLE OF POINT OF TOOTH 
 
 Fig. 23. Laying Out of Worm Gear Tooth 
 
 with draft and core prints to attach to both sides, as shown in Fig. 22. 
 If the pattern were made complete it would be necessary to make the 
 total number of teeth, while by the use of a core box it is possible to 
 get along without forming so many teeth, and thus reduce the work. 
 Also, if the pattern is made in halves and the two parts of the mold 
 should shift slightly it would deface the teeth. 
 
 There are a number of different ways in which worm gear teeth 
 can be laid out and made and there is much difference of opinion 
 as to the best method, but the following shows one which practice has 
 proven to be successful. Fig. 23 shows the manner in which a block 
 
BEVEL GEARS 
 
 27-IV 
 
 can be laid out and worked to shape from the solid. The outline of 
 the block is shown by the dotted lines. The block should be so formed 
 that it will fit the curve of the worm at the top of the tooth and the 
 curve of the face of the wheel at the bottom of the tooth. In this case 
 the outlines are laid off on the two'ends and connected as shown. 
 
 o « 
 
 ^s 
 
 The method of obtaming the angles corresponding to the root 
 of the tooth, the pitch diameter and the point of the tooth as necessary 
 for the lay out shown in Fig. 23, is shown in Fig. 24. This is done 
 by developing the circumference of the worm at the root, pitch diam- 
 eter and point of the thread and erecting at one end of each of these 
 
28-IV 
 
 GEARIXG 
 
 lines a perpendicular equal to the circular pitch. The diagonal lines 
 connecting the tops of these perpendiculars with the end of the lines 
 representing the different circumferences will give angles as shown. 
 Another method of making the tooth is shown in Figs. 25 and 26 
 and 27. In this case they are made by turning up rings and cutting 
 one tooth from each ring. While this does not give a theoretically 
 correct form of tooth it will give one close enough for all practical pur- 
 poses. The angle of the tooth is determined as shown in Fig. 24. 
 
 Fig. 26. Rin^ for Making Tooth 
 
 Fig. 27. Face Plate with Center 
 Line Drawn on It 
 
 In carrying out this method a faceplate is placed on the lathe and 
 the angle piece A, Fig. 25, is attached to it. This should have an 
 angle corresponding to the angle of the tooth on the pitch line, that is, 
 it should be the same angle as the center line of the thread on the 
 paper lay out for the worm pattern. To this block should be secured 
 the center disc B which is turned to a diameter equal to the inside 
 diameter of the rings shown in Fig. 26 and clamped. Piece C is fitted 
 with the necessary dowel pins to properly locate it and also with the 
 clamping screw. The rings. Fig. 26, are then turned up to the proper 
 cross section, the outside diameter being left somewhat larger than 
 required. 
 
 The piece of the ring to be used for a tooth should be cut from 
 the portion having the grain running lengthwise, that is, either the 
 piece A or B, Fig. 26, should be used. This point must be observed 
 in securing the rings in the chuck. 
 
BEVEL GEARS 
 
 2&-IV 
 
 After the rings are secured in the chuck, the outer diameter is 
 turned to coincide with the outer diameter of the worm wheel or the 
 segment of the same which is used in the core box. Before the ring 
 is removed from the lathe a center line corresponding to the line C-D, 
 Fig. 26, should be drawn upon it. 
 
 In Fig. 27 the face plate is shown with the clamp and ring removed 
 and with the center line C-D drawn upon it. Fig. 28 shows the manner 
 in which the core boxes are arranged with the tooth sections in place. 
 The portion of the rim carrying the teeth should be cut diagonally 
 as shown at A and B, so as to allow the rim to be drawn back from 
 
 Fig. 28. Segment for Core Box 
 
 the core in sections. In the case of a worm having a very coarse pitch 
 the teeth are usually made loose and secured in place by dowel pins 
 so that the rim is withdrawn first and then the teeth withdrawn from 
 the core. 
 
 No matter whether the teeth of the worm gear pattern are worked 
 from the solid block or are turned and shaped, it will be found neces- 
 sary to try the points for clearance, as otherwise they will interfere 
 when leaving the worm. Fig. 29 shows a way in which the segment 
 of the core box or the worm gear pattern can be mounted and revolved 
 past the worm for this purpose. The worm being arranged to revolve 
 on the centers in its core prints and the segment to swing on a post 
 or in any other convenient manner. 
 
30-IV 
 
 GEARIXG 
 
 Usually it is best to attach two or three teeth first, try them and 
 dress them for clearance, and then dress the balance of the teeth to 
 correspond with these. 
 
 The following modification may be preferred by some pattern- 
 makers and has much to commend it: 
 
 , Fig. 29. Testings Teeth of Segment for Clearance 
 
 To make large worm wheels without making all of the teeth and 
 without a core box, make the pattern the same as if you were going 
 to core the teeth, placing a core print or clearance piece around the 
 outside of the pattern as shown in Fig. 30. Then make a short seg- 
 ment of the pattern with a few teeth, as shown. After the pattern is 
 
 Print Cope or Partiag Line 
 
 T 
 
 M. 
 
 HALF SEC. O-a 
 
 Fig. .30. Section of Pattern for Worm Gear 
 
 rammed up and drawn from the mold take the segment, Fig. 30. and 
 keeping the shoulder B against the shoulder in the mold left by A, 
 step the piece around the mold, marking with flour or parting sand. 
 In this stepping off care should be taken to see that you have the 
 right number of teeth, as it is very easy to lose or gain a tooth in a 
 
BEVEL GEARS 
 
 31-IV 
 
 large wheel. After the spacing has been done place the segment at 
 the starting point and place a block to make a parting at one end of 
 the segment. This block, however, is only necessary for the first 
 ramming. 
 
 Sand should then be rammed up opposite the segment and the 
 segment screwed out and placed into the next mark, this section rammed 
 and so on, until the wheel is finished. This method will often make a 
 truer wheel than any made in cores, as there is always a fin where 
 cores meet. Then, too, if the cores do not space accurately and have 
 to be filed, this will result in either a wide or a narrow space v/here the 
 cores meet. 
 
 Sanding Gear Teeth to Form 
 
 In place of the method of jigging the teeth to form with the aid 
 of a plane they may be ground to form with a sand paper roller. This 
 can be applied to either spur or bevel gear teeth and will be found 
 much more rapid than the jigging process and just as accurate. Fig. 31 
 illustrates two views and a cross section of the sand roller or mandrel, 
 
 Position of -Tig Sanding Face 
 Flank and Btint of Tooth 
 
 Hard Wood Strip E-E ■■" 
 Slot D-D 
 
 Fig. 32. Gear Tooth in Jig 
 
 Enlarged Section X-X 
 Fig. 31. Sanding Gear Teeth 
 
 with the jig in two positions during the operation of sanding. The 
 roller is turned up of any convenient diameter, say 4 to 4^/2 inches, 
 with shoulder B-B at one end for guiding the jig. A depression C-C 
 of about 1-16 inch in depth and in width a little larger than the length 
 of tooth, is now turned down and a piece of garnet paper cut to the 
 length C-C and secured to the roller by the aid of the slot D-D and 
 strip E-E. This manner of securing the paper to the roller has a 
 decided advantage over gluing, as the paper is readily replaced without 
 the usual delay waiting for the glue to set. It also avoids the trouble 
 apt to occur by the paper swelling or buckling by the moisture from 
 the glue. 
 
32-1 V 
 
 GEARIXG 
 
 The dimensions F-F and G-G, which are of sufificient width to 
 give a good bearing for the jig, are now turned down on a Hne with 
 the garnet paper, or to the same diameter. The completed jig is 
 shown in greater detail in Fig. 32, the opening H-H in the center being 
 cut out to receive the tooth blocks. The latter is shown in position and 
 is secured in place by two screws. As the bottom of the tooth block 
 must conform to the diameter of the rim of the wheel upon which the 
 
 LL 
 
 Fig. 33. Building a Bevel Gear Body 
 
 teeth are placed, so must the bottom of the opening H-H in the jig 
 be identical with the same diameter. 
 
 With the jig and roller completed the sanding of the teeth takes 
 our attention, and this is a good job for the cub. The tooth blocks 
 having been gotten out of sufficient width, both ends are trimmed to 
 the exact length and angle, and next with a round sole plane, or the 
 bit in the jack plane rounded up. The edge of the block is dressed up 
 to conform to the bottom of the opening H-H in the jig. Fig. Z2. The 
 tooth block is now placed in the jig and secured with the two screws, 
 and after the cutting ofif with a chisel of the surplus material at the 
 corners J-J of blocks, the sanding follows in order. 
 
BEVEL GEARS 
 
 33-IV 
 
 Controlled by the shoulder B-B, Fig. 31, the jig is held against 
 the roller and guided over it as it revolves. 
 
 Construction of Bevel Gear Pattern Bodies 
 
 Fig. ZZ illustrates two cross-sections of the rim in the course of 
 completion, also a part plan and cross-section of the web. To the left 
 
 Fig. 34. Setting Teeth on a Bevel Gear 
 
 of the center line is shown a cross section of the segment work prior 
 to turning, which also shows the manner in which it is built up on the 
 face plate, while to the right of the center line is shown a cross-section 
 
34-IV GEARIN.G 
 
 of the rim at the completion of turning the back or inside of the rim, 
 the offset or shoulder K-K being turned down to receive the web. 
 A portion of the latter is shown directly over and in position for 
 placing into the rim. The three pieces of material, one being shown 
 b\ L-L, which form the greater portion of the web, are overlapped 
 and secured together with glue and screws. The corners M-M and 
 segments N-N are fitted in place and glued. This portion of the pat- 
 tern is now secured to a face plate, and the outer diameter turned to 
 fit snugly into the shoulder K-K of the rim, in which position it is 
 secured with screws and glue. It will be found more convenient if 
 this web portion of the pattern is gotten out first and the outer diameter 
 turned to shape, and the offset, or shoulder, K-K, in the rim, turned 
 out to fit the web, and the latter can then be secured in place before 
 removing the rim from the face plate. The back of the rim is then 
 given a coat of shellac and sandpapered down and removed from the 
 face plate, turned over and centered and chucked directly upon the 
 web of pattern, as shown in Fig. 34. This illustration shows one 
 manner of accurately placing and securing the teeth upon the rim. 
 
 The face of the rim or the root of the tooth line is now turned to 
 the required angle with the aid of a templet, which should extend 
 across the entire diameter of the rim. Next attach to the web at the 
 center of the work, as shown, the block or post P-P. The post should 
 extend far enough out to allow the apex of a cone, of whch the rim 
 is the frustum, to be turned at its outer point, S-S. If the face angle 
 of rim is correct, the distance R-R from the plane of the pitch diameter 
 of wheel to the apex of cone thus formed should be equal to the pitch 
 radius of pinion. Spaces corresponding to the number of teeth are 
 next spaced off on the face of the rim, near its outer diameter. The 
 lines T-T-T are now drawn across the face of the rim through the 
 points stepped off and intersecting at the point S-S of post. In placing 
 the teeth on the rim, glue is applied to the tooth and the side of the 
 tooth is set to one of the lines T, in which position it is held for a 
 moment until the glue slightly sets. The sides and top are then tried 
 for accuracy with a straight edge, for if the tooth has been accurately 
 set, all lines of the tooth should intersect at the point S-S. The spaces 
 should also be tried for correctness, with the calipers from the adjacent 
 tooth. When all the teeth have been so placed and their correctness 
 assured, they are nailed down and a leather fillet rubbed in. With 
 the getting out of the hub and ribs and the remainder of the pattern, 
 our work is completed. 
 
SECTION V 
 
 REPRESENTATIVE PATTERNS 
 
 CHAPTER 1 
 PATTERN FOR A THROTTLE VALVE BODY 
 
 While all valves are throttles, a throttle valve is generally under- 
 stood to designate that design of valve used in regulating or con- 
 trolling the steam supplied for reversible engines. These conditions 
 usually require a quick action ; hence, the valves are generally operated 
 by levers. This necessitates the balancing of the valve so as to counter- 
 act the steam pressure, which changes the interior body somewhat from 
 that of an ordinary globe valve. 
 
 The valve body illustrated and described in this article is known 
 as a three way, 12 x 12 x U^.-in. throttle valve. This particular design 
 is frequently used in connection with a pair of heavy reversible bloom- 
 ing mill engines. Fig. 1 shows two views of the valve body, and also a 
 section on the line A-A ; this section being taken through the intake 
 opening. 
 
 To many persons the interpretation of the valve body drawing is 
 always a perplexing problem, but this problem has a comparatively 
 simple solution, for with the aid of a sheet of carbon paper and piece 
 of drawdng paper, the outline of the core can be traced in each view 
 together with their center lines. Now by folding these carbon sheets 
 along their center lines and placing them in a vertical plane in their 
 relative positions, with regard to the accompanying views, the results 
 will be surprising, as it will readily be seen what is required and the 
 manner in Vv'hich the cores can be made and placed together in the mold. 
 Before laying out of a full size section, and the commencing of 
 the construction of such a pattern, its position and method of molding 
 miist be decided upon. 
 
 This pattern might be parted in the plane of Fig. 2, which shows 
 the completed pattern. This would, however, necessitate a loose flange 
 and a more intricate core ; or it can be parted as in the case imder 
 
2-V 
 
 REPRESEN TA 111 'E PA TTERNS 
 
 Fig. 1. Two Views and Section of Throttle Valve 
 
 discussion at right angles to the plane — that is, vertically along the 
 line B B, with the bonnet opening downward. This method of starting 
 provides a convenient and positive manner of setting the cores as well 
 as simplifying the construction of the core boxes. 
 
 Fig. 3 shows the cope and drag parts of the pattern built up 
 of segments and ready for turning. These two parts can be dowled 
 together or fitted together with a male and female joint. The former 
 method probably being preferable, as it does not require the parts to 
 
A THROTTLE VALVE BODY PATTERN 
 
 3-V 
 
 be rechiicked. After the parts have been turned separately, they are 
 placed together, marked, and the dowel pin holes bored. 
 
 The manner in which the opening connections are built up in 
 halves and turned is shown in Fig. 4. To avoid a feather edge, and 
 also to assist in turning and gluing these parts to the pattern body, 
 ample stock is left as shown at C, and afterwards worked off into the 
 fillet. The core prints are shown in Fig. 5. The core prints and 
 connections could be built up and turned entire, but it is more con- 
 venient to turn them separately and attach later. 
 
 Fig. 3, Stock Glued up for Throttle Valve Pattera 
 
 Before proceeding with the discussion of the construction of the 
 two core boxes with their detachable parts, let us familiarize ourselves 
 more fully with the form and manner of jointing the cores required 
 in forming the interior of the body. If the carbon tracings have been 
 obtained, as heretofore explained, and are laid out in their relative 
 positions to one another, they will appear, of course, without the joints 
 
 Fiar. 4. 
 
 Pattern for Opening Connection Throttle 
 Valve Body 
 
 Fig, 5. Core Print for Throttle Valve 
 
 and print portion. The assembled cores, together with a section of 
 the mold, are shown in Fig. 6. The two half cores, D and E, forming 
 one portion of the body, are made in the same box and are jointed in 
 the vertical plain, or at right angles to the joint with core F or the 
 parting of the mold. Cores F and G are jointed as shown, and are 
 made from the same box — core F forming the drag portion of the 
 
4-V 
 
 REPRESEXTA TIl'E PA TTERXS 
 
 body while core G forms the cope half of the intake opening. To 
 assist in locating- and setting the cores, D, E, and F together in the 
 mold, a projection with corresponding depression is formed in the 
 
 joint as shown at H. 
 
 'iectloii I- 1 
 
 Fig. 6. Sections of Cores and Molds 
 
 In placing the cores in the mold, core F, with core G attached 
 by pasting and wiring, is set in position. Cores D and E are next 
 
A THROTTLE VALVE BODY PATTERi\ 
 
 5-V 
 
 secured together in like manner and set upon the ones already placed. 
 The plan and three sections of the core box used in forming the 
 cores D and E are shown in Fig. 7. The spherical portion of the box 
 is built in segments and turned out. It is then flattened off as shown 
 to receive the material forming the opening K, and also~ the board 
 A B, to which is secured the parts L, Z and M, forming the valve 
 
 chamber. The part M is shown in position in the lower right hand 
 section, N O. As these two half cores, D.and E, are made from this 
 box, it requires the loose parts to be changed for each core — that is, 
 parts L and Z are used in forming core D, while part M is substituted 
 for forming core E. 
 
6-V 
 
 REPRESEN TA Til 'E PA TTERNS 
 
 Prior to the rolling over of this box, when forming core D, part 
 Z is removed and piece L drawn back. The depressions left vacant 
 by these two parts are filled with green sand to support the over* 
 hanging portion of the core while it is being dried. 
 
 It will be observ^ed that the part M consists of a board fitted into 
 
 the spherical portion of the box to flatten it off, and to which is secured 
 this portion of the valve chamber. 
 
 Cores F and G are formed in the box shown in the plan and sec- 
 tions in Fig. 8 ; the portion R, forming the lower part, being built up 
 
A THROTTLE VALVE BODY PATTERN 
 
 7-V 
 
 by segments, turned and secured to the frame S, which is built up, 
 sawed out and attached to the material T, as shown, so as to form 
 the intake opening. This portion of the box is then dressed out with 
 the aid of a templet to the proper spherical form as shown by the 
 section U V. Plate W is dropped into the top of the box as shown 
 to form that portion of the metal thickness of the valve chamber which 
 extends beyond the center line of the valve body. 
 
 Fig. 9. Stop-Off used for ForminR Core G 
 
 Print X is suspended in the center of the opening and forms the 
 depression H, shown in core F, Fig. 6. Core G is formed in this box 
 also with the aid of the stop-off piece Y, which is dropped into the 
 box and braced as illustrated in a partial section of the core box 
 shown in Fig. 9. 
 
8-V 
 
 REP RES EX TA Til 'E PA TTERNS 
 CHAPTER II 
 
 PATTERN FOR A PINION HOUSING 
 
 Of the accompanying illustrations, Figs. 10 and 11 show one-half 
 of an enclosed pinion housing weighing about 28,000 pounds and of 
 a design frequently used on modern roll trains. In constructing large 
 patterns of this description, when part of the mold must be lifted 
 away before the pattern can be drawn, it is often advantageous to 
 arrange the mold somewhat after the manner of loam molds, that is, 
 with the aid of a cast iron plate or flask, so that the side of the mold, 
 usually termed the cheek, can be lifted awav from the seat or bed, 
 leaving the pattern free to be drawn. 
 
 ^1 I 
 
 I" T 
 
 Li^-l/ 
 
 Fig. 10. Pinion Housing Pattern End and Side Elevations 
 
 When beginning the pattern, it is necessary to lay out a full sized 
 plan and cross section upon a good substantial board. The straight 
 portion of the pattern is built up of segments, as shown in the upper 
 part of Fig. 12. In doing this work care should be taken to saw the 
 segments to as near the finished size as possible, so as to reduce the 
 amount of finishing to the minimum. If the parts are laid out care- 
 fully and band-sawed accurately to lines, it will onlv be necessary to 
 
A PINION HOUSING PATTERN 
 
 9-V 
 
 clean up or smooth the surface. A Httle care at this point will save 
 a great deal of work and time. 
 
 After the parts are built up, the openings for the doors A, Figs. 
 10 and 12, are cut out of each side as shown. It will be noticed that 
 a flange is necessary at the bottom of the main body of the pattern 
 and a fillet piece at the top, as shown by the dotted outlines in the 
 upper part of Fig. 12, the flange being shown at B and the fillet piece 
 at C. Both the flange and the fillet piece are built of segments turned 
 and cut in halves, as shown at the bottom of Fig. 12. The halves are 
 then secured to the body in the position shown by dotted lines. The 
 intervening space from D to E, between the two halves of the pattern, 
 is filled in with segments and dressed ofif to correspond with the 
 section of the ends. 
 
 Fig. 11. Half Plan and Half Section of a Pinion Housing 
 
 It is necessary to make a door frame to go around the doors A. 
 Three views of this frame are shown in the lower part of Fig. 12 
 between the flange and the fillet piece, and, of course, it is necessary 
 to make one of these for each of the doors. These parts are built up 
 of segments and worked out to fit the body of the pattern, to which 
 they are secured. 
 
 The pads to reinforce the flange at the bolt centers are gotten 
 out as shown above the door frame. Fig. 12., and secured to the flange 
 at the proper points, as shown in Fig. 10. By referring to Fig. 11 
 and the dotted lines in Fig. 12, it will be noticed that the inside hubs 
 project into the pattern some distance. Fig. 13 shows a plan and 
 cross section of this portion of the pattern as it will appear after being 
 built up, the parts turned and fitted together. It will be noticed that 
 they are joined by a good substantial rapping bar shown at R. The 
 space between the two hubs is filled in and worked out into a large 
 fillet. The cross supports A and B are used in holding this portion 
 of the pattern in place, while the inside of the body is being rammed 
 up. To facilitate the ramming of the inside of the body it is necessary 
 
10-V 
 
 RnrRESEX TA Til 11 PA TTERXS 
 
 to provide a series of oblong openings as indicated b}' the dotted lines 
 at HH, in the upper part of Fig. 12. One-half of each of these open- 
 ings is shown on the iiiibs in Fig. 13, and the other half on the portion 
 of the fillet piece shown in the lower left hand corner of Fig. 12, the 
 half openings in each case being indicated by the letter H. 
 
 Fig, 13. Interior Hubs 
 
 Fig. 12. Body of Pattern. Flange, Fillet 
 Piece and Details 
 
 The body portion of the pattern is now completed and building 
 the web is next in order ; to facilitate the handling and storing of this 
 part of the pattern, it may be made in halves with a longitudinal joint 
 through the center and the halves lined and bolted together while 
 being molded. 
 
 One-half of the partially completed web is shown in Fig. 14, 
 illustrating the manner in which it is built up of segments and one 
 side closed. After the two halves of the web are completed, they are 
 pinned and bolted together and dressed ofif. 
 
 The two outer hubs required are shown in Fig. 15, built up and 
 turned ready to be placed in position and secured by dowels. 
 
 The feet of the housing must be also be gotten out and secured in 
 the same manner. The details for this portion of the work are shown 
 in Fig. 16, the three figures at the top showing the 'details of one foot. 
 
A PINION HOUSING PATTERN 
 
 11-V 
 
 There would be one of these parts required for each hand, that is, 
 right and left for each half of web. It will be noticed that the pro- 
 jecting lip at the lower portion of the foot is secured with loose pins 
 so that these parts can be drawn into the mold after the main portion 
 of the pattern has been removed. The foot for the opposite side of 
 
 i_i J 
 
 Fig. 14. Web Portion of Pattern Lagged up 
 
 Fig. l.S. Outer Hub 
 
 the web is shown in detail in the three views in the lower part of 
 Fig. 16, and it will also be necessary to make two pieces of this, one 
 right and the other left hand. These two parts of the foot, together 
 with the intervening thickness of the web, give the desired bearing 
 
 Fig. 16. Foot of Housing, 
 
 for the foundation of the housing. It will be noticed that in the piece 
 shown in the lower right hand corner of Fig. 16 there is a parting 
 along the line BCD, and that the intervening space between this 
 joint and the body is filled in and worked out in the fillet as shown. 
 
12-\- 
 
 REPRESEN TA TIl^E PA TTERNS 
 
 After the top or cope side of the web has been finished it is turned 
 over with the open side up and the body of the pattern placed upon it, 
 located, and secured in place with dowels. The portion of the foot 
 shown by the three views at the bottom of Fig. 16 is also placed and 
 secured with screws and pins. The portion of the web extending 
 
 Fig. 17. Web Portion of Pattern Completed 
 
 outside of the body and up to the fillet of the foot is now filled in with 
 material of the necessary thickness to give the required thickness of 
 web as shown in Fig. 17, the partial cross section on the line X X 
 indicating the thickness of the pattern at that point. 
 
 A cross section of the finished pattern taken along the line M N 
 O P, Fig. 10, is shown in Fig. 18. This also shows the manner in 
 
 Fig. 18. Section of Finished Pattern 
 
 which the trunnions are turned and fitted to the pattern, being secured 
 with loose dowels and pins. 
 
 A plan and section of the core box for making the cores for the 
 two babbitted bearings in the hubs is shown in Fig. 19. The core 
 prints shown in the core boxes ar to receive the dovetailed cores 
 
A PINION HOUSING PATTERN 
 
 13-V 
 
 made in the core box shown at the bottom of Fig. 19, and intended 
 for forming the rests or anchorage for the babbitt, as shown in the 
 cross section of the casting in Fig. 11. 
 
 When molding the pattern, a hole is dug in the floor to such a 
 depth that it will bring the parting line of the cope about level with 
 the floor and a level bed is struck off. The body of the pattern is now 
 placed upon the bed and the inside rammed up to about the height of 
 the bosses. The bosses secured to the supports A-B, shown in Fig. 13, 
 are then set in place and screwed down. If a cast iron plate with 
 suitable lifting lugs and an opening in the center, conforming some- 
 what to the outline of the body, is to be used for supporting and 
 lifting away the cheek, it is now lowered over the pattern and placed 
 upon the bed, and the ramming up of the cheek is the next operation. 
 
 Fig. 19. Core Boxes for Bearings 
 
 During the operation of ramming up the cheek, and when this portion 
 of the mold is nearly completed, the web portion of the pattern with 
 the lower feet secured to it, is placed upon the body, the trunnion set 
 in place, and the ramming of the cheek completed, up to the parting 
 for the cope. The inside of the mold about the hubs must also be 
 rammed up to the oblong openings. The supports for the inner hubs 
 are now removed, and the outer hubs and upper part of the foot set 
 on the web. The cope is then placed in position, rammed up and 
 lifted off in the usual manner. The web of the pattern is then drawn. 
 The cheek is next lifted away, so as to leave the body of the pattern 
 exposed and free to be lifted from the core. The mold is now dressed 
 and skin dried, when it is ready to assemble. The gates and runners 
 are prepared, the mold assembled, and is then ready for weighting 
 down and pouring in the usual manner. 
 
14-V 
 
 REPRESEXTATIVE PATTERNS 
 CHAPTER III 
 
 HAWSER PIPE PATTERNS 
 
 Hawser, or "hawse" pipes, as they are generally called, are usually 
 made in pairs, consisting of a right and left hand pipe. The length 
 of the pipe, its diameter, and the angle of the ends, are governed by 
 the angle upon which the pipes are set with the deck, by the outlines 
 of the hull and the size of the anchor chain. 
 
 The pipe with the out board flange is cast entire, as shown in Fig. 
 20, while the deck flange as shown in Fig. 20 is cast separate and 
 subsequently riveted upon the deck. These pipes are usually of cast 
 
 Fig. 20. Hawser Pipe 
 
 Fig. 21. Bow of Hul 
 
 iron and their construction affords a very good example of what may 
 be termed cross templet and hollow pattern work. 
 
 It will readily be seen that this form of templet and method of 
 making a pattern can be used in a very large number of ways for 
 special pipes, etc. The outboard opening of these pipes often assumes 
 different forms, to accommodate the stock of the anchor. In some 
 cases the pipe flares outward in the form of a bell. When this is the 
 case, it requires a complete pattern parted longitudinally with the 
 inside, worked out to form the desired metal thickness. The inside of 
 the pattern then serves as a core box for forming the green sand core, 
 the core being lifted out with the aid of a core bar or skeleton. 
 
HAWSER PIPE PATTERNS 15-V 
 
 To illustrate more fully the position and arrangement of these 
 pipes when in place, two views of the bow or forward part of the hull 
 are shown in Fig. 21. 
 
 The customary practice in most ship yards for transferring the 
 angle of the deck and the hull to the pattern is as follows: The pat- 
 tern is made solid or lagged up, and of about the required length. It 
 is then shoved down through the openings provided in the deck and the 
 hull and secured in place. The outline of the opening is next scribed 
 around the pattern and is dressed off while in this position. Material 
 equal in thickness to the contraction in the length of the pipe is added 
 to one end. Next a core print is dressed off to conform to the angle 
 
 Fig. 22. Three \'iews of Cross Templet 
 
 of the deck and attached to the pattern. Any patternmaker who has 
 been so unfortunate as to fall heir to this particular job will agree 
 with the writer that the method illustrated and to be described is far 
 superior to the method mentioned. 
 
 The form of templet used in connection with this method is termed 
 o cross templet, as a cross section of the templet would be in the form 
 of a cross, as shown in Fig. 22, which illustrates three views of the 
 templet during the three stages of its completion as applied to the 
 hawse pipe pattern. At the left in the figure is shown the templet 
 nailed and bracketed together, and ready for the next operation which 
 is the cutting of the angle on the ends. To cut the angle on the ends 
 the templet is shoved down through the opening on the deck and out 
 through the opening in the hull and clamped in position. The ends 
 are next sawed off and dressed to conform to the angles of the deck 
 and hull. The templet would now appear as shown in the central view 
 of Fig. 22. The work thus far is done by the templet maker, who 
 now turns it over to the patternmaker. 
 
 The separate parts of the pattern are shown in Fig. 23. At the 
 right and left of the figure are the two barrel or cylindrical sections 
 which have been sawed and dressed to conform to the angles of the 
 ends of the templet which is shown in the center of the figure. These 
 two cylindrical ends of the pattern are lagged and glued up over 
 
16-V 
 
 REPRESENTATU'E PATTERNS 
 
 cylindrical heads having a diameter equal to the inside diameter of 
 the pipe. A dry joint is left in the lagging on each side to permit the 
 removal of the pieces from the heads and the cleaning of the inside 
 of the pieces. The outer diameter is next turned to size, the lagging 
 being secured to the circular heads with screws, which are removed 
 as soon as the turning is completed. The heads are then taken out 
 and the inside of the lagging cleaned up. The cylinders are then glued 
 together as shown at the right and left of Fig. 23. 
 
 The templet being made of the same diameter as the outside of 
 the pipe necessitates the cutting down of each end of the templet as 
 shown at A, to allow this portion of the templet to enter the inside of 
 the pattern. The ends are then slipped over the templet and secured 
 with screws, the cylindrical ends being dressed off to conform to the 
 
 Fig, 23. Separate Parts of Pattern 
 
 angle of the templet as shown. Of course, allowance has to be made 
 for the shrinkage of castings and this is accomplished by nailing strips 
 on one end of the templet as shown at B, Fig. 23, the thickness of these 
 strips being equal to the shrinkage which would take place in the 
 length of the pipe. At the top of Fig. 23 is shown a core print which 
 is attached or inserted into the end of the pattern which is without a 
 flange, that is, the deck end of the pattern. This core print is lagged 
 up in the ordinary manner and the outside turned to the proper diam- 
 eter. If the inside diameter of the pattern has been lagged up care- 
 fully the core print should slip into it snugly. Of course, it is neces- 
 sary to make some allowance for clearance. The slots shown at C 
 in the core print must be cut to allow the core print to slide past the 
 templet. A temporary head is used in the upper or open end of the 
 core print when lagging it up and turning it and is subsequently re- 
 moved, after which the slots are laid out and sawed to suit the templet. 
 The assembled pattern is shown in Fig. 24, in the correct position 
 
HAWSER PIPE PATTERNS 17-V 
 
 for molding. It will be observed that the pattern is so placed as to 
 cause the flange to set in a perpendicular position, this being necessary 
 to allow the coping off of the flange end of the pattern. 
 
 The flange, ready to attach to the pattern, is shown at the bottom 
 of Fig. 23. It is built up in segments and worked out to form, being 
 parted along the line D D, so that the upper half can be allowed to 
 lift off with the cope when molded. Loose dowel pins are used to 
 secure the entire flange in position. A chipping strip E, Fig. 24, of 
 
 Fig, 24. Assembled Pattern 
 
 about one inch in width and ^ inch in thickness is attached around 
 the outer edge of the flange with loose pins. The object of the chipping 
 strip is to facilitate the fitting of the flange to the hull. Where hawse 
 pipes are of the same diameter, one templet may be made to serve 
 for several pipes, or the circular end may be readjusted upon a templet 
 trimmed to the new angle and the old pattern thus made to serve for 
 more than one vessel. 
 
 Molding of the Pipe 
 
 The molding of this pipe contains some points of interest, par- 
 ticularly in connection with the checking oft' of the flange end. A plan 
 and two cross sections of the completed mold are shown in Fig. 25. 
 At the top of the illustration is shown a plan of the mold with the 
 pattern in place ready to have the flask placed in position for ramming 
 the cope. At the right is shown a cross section through the cheek on 
 the line F F, while at the bottom of the figure is shown a longitudinal 
 section of the complete mold on the line G G. In beginning this 
 work provision is first made for checking oft' the end containing the 
 flange, after which the pattern is bedded in. During this operation 
 that part of the mold occupied by the open space H between the two 
 lagged up ends of the pattern is made up by ramming the sand about 
 the pattern at the ends, removing the pattern and striking out the 
 central portion with a straight edge to conform to the rammed up 
 portion. Parting sand is now applied to this struck off surface and 
 the pattern returned to place. A parting is next made around the 
 pattern and up to the line of the cheek. Sand is used to fill up the 
 opening H in the cope, the sand being struck oft' to conform to the 
 ends as shown. 
 
18-V 
 
 REP RES EN TA TITE PAT TERNS 
 
 A bed is made to receive the cast iron lifting plate I which is 
 dropped in place. For illustration a plate of triangular form is shown, 
 but the shape and size of the plate is generally governed by the avail- 
 able material about the foundry. The flange which is not fast is now 
 secured to the pattern with loose pins and the ramming up of the 
 cheek commenced. A parting is made at the rounding surface of 
 
 
 
 ^\ri-/S:if Sectlo,ir-F 
 
 •-^>?< 
 
 Farting 
 
 ^?P 
 
 Yi«. 25. Plan and Secti m of Mold 
 
 Coat Iron Flat* I 
 
 the flange above the parting of the mold as shown. A parting has also 
 to be made along the line of the joint of the dry sand core in the 
 cheek. This is accomplished by ramming sand into the end of the 
 pattern and making a parting by striking it off even with the pattern. 
 This parting is then covered with paper while the cheek is being 
 rammed. 
 
 The cope is now placed in position and staked dow^n. It is then 
 rammed up and lifted off in the usual manner. The upper half of the 
 flange lifts oft' with the cope. The cheek is next slightly lifted and 
 drawn forward in the direction of the arrow, allowing the lower 
 flange to be drawn back out of the cheek. The body of the pattern 
 is then free to be drawn, with the exception of the point J, which 
 necessitates a slight longitudinal movement of the pattern toward the 
 cheek to allow this point to clear before the pattern is drawn from the 
 mold. 
 
HAWSER PIPE PATTERNS 19- V 
 
 The mold is then dressed in the usual manner, the cheek moved 
 back into position and backed up by ramming the sand behind it. The 
 dry sand core which forms the interior of the pipe and which is con- 
 structed with the aid of a frame and angle box, is now set in position 
 upon chaplets and butted up to the cheek as shown. The cope is placed 
 on, weighted, and the mold prepared for pouring. This entire mold is 
 made in green sand, with the exception of the dry sand core mentioned. 
 
20-V 
 
 REPRESEXTA Til 'E PATTERXS 
 CHAPTER IV 
 
 A NOZZLE PATTERN 
 
 Nozzles or saddles are usually employed in forming connections 
 with shells or similar boiler work, and are made in various forms and 
 sizes. The illustrations show a common form of nozzle. The pattern 
 work and the operation of molding a piece of this shape is of a com- 
 paratively simple nature. It may contain some points of interest, as, 
 
 Fig. 26. Nozzle Casting 
 
 for example the plugging of impressions to receive cores when core- 
 prints cannot conveniently be used, also another feature is the arrange- 
 ment of the three-part flask. 
 
 Fig. 26 shows a nozzle casting as it would appear ready to be 
 
 Coie-piint 
 
 Plug 
 
 7. Nozzle Pattern Assembled 
 
 riveted to the shell. The assembled pattern is in two parts and 
 appears in Fig. 27. This illustration gives the general construction, 
 which of course is segment work, also the location and formation 
 
A NOZZLE PATTERN 
 
 21-V 
 
 of the joint, the latter being shown in greater detail at the left. It 
 will be observed that the entire draft of the inside diameter of the 
 pattern is in the direction of the arrow, while the draft on the outside 
 diameter of the pattern is toward the joint. 
 
 As the upper part of the pattern is a simple lathe operation, we 
 will discuss only the turning and working out of the lower portion, or 
 that part of the pattern containing concave flange. To the left of the 
 center line in Fig. 2'^ is shown a cross section of the first operation, 
 that of building the ring up in segments. At the right of the center 
 line is shown a cross section of the piece after having passed through 
 the operation of turning and of fitting the joint. 
 
 Next the concave surface must be dressed out. This can be 
 accomplished very nicely and accurately by nailing together a light 
 
 Fig. 28. Details of Saddle Flange Construction 
 
 Figr. 29. Working of Saddle Flange to Form 
 
 frame of the proper depth, the two ends of which are cut out to the 
 required radius of the flange. The frame is now tacked down on 
 the work table, and the work dropped into it, secured and dressed 
 out to conform to the circular ends of the frame. A cross section of 
 the flange would now appear as shown to the right of the center line 
 in Fig. 29. 
 
 The thickness of flange is scribed around the outer diameter, 
 and the dressing of the flange to thickness accomplished with the 
 gouge and calipers. When this operation has been completed, a cross 
 section of the flange would appear as shown to the left of the center 
 line in Fig. 29. 
 
 x^s the outer diameters of these flanges are usually made on a 
 radial line with the center of the shell upon which they are placed, 
 this will cause the edge to be irregular ; it must be laid out on the 
 
22-V 
 
 REPRESENT A Til 'E PA TTERNS 
 
 concave side of flange and dressed off with the aid of a templet and 
 the eye. 
 
 A handy little tool for laying off or scribing the width of the 
 flange and rivet circles is shown at the top of Fig. 29. The gage is 
 applied and guided by the inside diameter of pattern. 
 
 Next the rivet centers are stepped off around the rivet circle and 
 holes radiating toward the center of shell are bored. The diameters 
 of these holes are equal to the diameter of the cores to be used. A 
 plug, shown in greater detail at the right in Fig. 27, is turned up to 
 fit these holes, the shoulder allowing it to project through the flange 
 the desired distance. 
 
 In molding the pattern the section of pattern containing the 
 straight flange is placed upon the follow-board in the reversed position 
 
 :::'^S''?'':^''!ili''^^^ 
 
 Fig. 30. Section of Mold 
 
 as shown in Fig. 27, and the cheek placed over it. This is followed 
 by the operation of ramming up the inner and outer diameter until the 
 joint of the pattern is reached. The balance of the pattern is now put 
 in place and the ramming of the cheek completed with a parting made 
 around the outer edge of the flange as shown in Fig. 30. The drag 
 is now located and rammed up in the usual manner. These two 
 parts of the mold are now clamped together, rolled over and the part- 
 ing for cope made. At the completion of its ramming the latter is 
 lifted off. The upper section of the pattern drawn, the cheek is 
 lifted off, the depressions to receive the cores formed with the plug 
 shown in Fig. 27, leaving the concave flange portion of the pattern 
 free to be drawn up over the center core which is formed by the 
 inside diameter of the pattern. The mold is now dressed, the cores 
 set and the parts of the mold returned to place and clamped together 
 as shown in Fig. 30. 
 
STEEL TRUCK BOLSTERS 23-V 
 
 CHAPTER V 
 
 MOLDING CAST STEEL TRUCK BOLSTERS 
 
 The truck bolster shown in Fig. 31 is that of the American 
 Steel Foundries and the drawings also show their method of molding 
 it. Green sand molds are employed in the production of practically 
 all of this class of work. This is true whether the bolster pattern be 
 mounted on a stripping plate machine, as in the case under discussion, 
 or be molded upon the floor. 
 
 The method of molding is comparatively simple, but affords a 
 very good example of the ramming up of a green sand core in place. 
 This operation may be applied to very good advantage in a great 
 variety of ways, especially in die producing of light steel castings 
 where the presence of dry sand cores is to be avoided if possible, 
 owing to their tendency to retard the shrinkage, as this shrinkage is 
 apt to result in a badly strained or cracked casting when resisted by 
 hard cores. This method may save some of the expense otherwise 
 incurred in the making up of dry sand cores and in the handling of 
 the same. 
 
 The success of the patternmaker in dealing with any problem of 
 this kind depends wholly upon his ability to see how the object or 
 pattern to be made will appear and how it may be molded in the most 
 practical manner. With these two points constantly held clearly in 
 mind the construction of the pattern becomes a secondary consider- 
 ation. For this reason the writer believes that large returns often 
 result from time spent over a drawing in studying every detail and 
 getting a thorough idea of what is desired by the draftsman and what 
 is required in the way of material, etc. When beginning any pattern, 
 whether it is to be mounted on a machine or molded on the floor, its 
 position and manner of molding must first be determined. 
 
 The truck bolster to be molded is shown in several views in Figs. 
 31 and 32. At the top of the illustr:.tion, Fig. 31, is shown a half- 
 side elevation and half-longitudinal section on the center line of the 
 bolster. At the bottom of the figure is shown a half-top and half- 
 bottom plan, while Fig. 32 shows two cross sections of the bolster 
 on the lines A- A and B-B, Fig. 31. The section A-A gives a cross 
 section of the bolster at the middle through the center plate, while a 
 section through the side bearings is shown at B-B. The stripping 
 plate line or the line of the parting is located at C-C, Figs. 31 and Z2. 
 
 In beginning the work, let us first take up the construction of 
 
24-V 
 
 KEF RES EX TA Til 'E FA TTERXS 
 
 (I* fn 
 
STEEL TRUCK BOLSTERS 
 
 25-V 
 
 the cope and drag portions of the pattern, as shown in their mounted 
 position upon the molding machine, Figs. ZZ and 34. These parts 
 should be made of hard wood, maple preferred, although in some cases 
 pine is used. The parts should be substantially put together and the 
 corners protected by light angle iron as shown. Fig. 33 illustrates 
 the cope portion of the pattern, which, owing to its shallowness, is 
 usually n.iade solid, the material being glued up edgewise, as shown 
 at the right in the cross section of the pattern on the line D-D. 
 This section is taken through the depression in the pattern which forms 
 one of the openings in the top of the bolster. In other words, these 
 openings in the top of the bolster are depressed in the pattern to a 
 depth equal to the metal thickness of the top of the bolster. These 
 
 Fig. 35 
 
 © 
 
 © 
 
 Steel Plate )i' Thick 
 
 © © 
 
 © 
 
 Flask Fin Plate 
 
 wn 
 
 Section T-'X' 
 
 Fig. 35. One Quarter of Steel Strippin§r Plate Fig. 36. Plan of Wooden Stripping Plate 
 
 depressions or openings thus form their own green sand cores during 
 the operation of molding. 
 
 Temporary patterns are made for the center plate G, side bear- 
 ings H, and guide flanges F, these parts being made of cast iron fitted 
 or turned up and subsequently properly located and secured in position 
 upon the pattern. 
 
 The drag portion of the pattern is shown in Fig. 34. This portion 
 of the pattern is constructed as a box section as shown at the right 
 in the cross section on the line E-E. The two ends of the pattern 
 are practically built in solid, to allow for the forming of the core print 
 at each end. 
 
 In constructing this portion of the pattern the sides may be gotten 
 
26-V 
 
 REP RES EST A Til 'E PA TTERXS 
 
 out about 2y2 inches thick, laid off, sawed and dressed to form. This 
 portion of the pattern, as well as the cope portion, should extend about 
 two inches below the stripping plate line. After the two sides have 
 been placed upon a level surface and squared up, they are secured 
 together with separating pieces and the two ends filled in solid. The 
 top is next filled in and dressed off to conform with the sides. As 
 the two oblong openings in the bottom of the bolster are formed by 
 a dry sand core with a core print setting, these two core prints J are 
 gotten out and secured in position as shown, as is also the center pin 
 core print K. With the binding of the corners of the pattern with 
 angle iron and the securing of the guide tianges F in position, this 
 portion of the pattern is completed, after it has had the usual applica- 
 tion of shellac. 
 
 Fig. 37 
 
 /Holding Don n Corei x 
 
 Fig. 38 ^' 
 
 Section y-N 
 
 Fig. 37. Section of Mold Fig. 38. Rie (or RaniminR up the Green Sand Core 
 
 As the mounting of the pattern upon the machine depends entirely 
 upon the raising and lowering operation and the arrangement of these 
 parts of the machine we will not discuss that part of the work, but 
 proceed with the fitting on of the material forming the stripping plate. 
 
 In most cases a steel plate about y2-mch in thickness is used, but 
 the writer has fitted up molding machines for this class of work with 
 a pine stripping plate about 1 ^-inches in thickness, the lumber being 
 substantially cleated together, and has found that such stripping plates 
 have successfully withstood the action of pneumatic rammers in the 
 production of several hundred castings. 
 
STEEL TRUCK BOLSTERS 27-V 
 
 If it is determined to equip the machine with a half-inch steel 
 stripping plate, the pattern is located and secured in its correct posi- 
 tion upon the operating device. A wooden templet is next gotten out 
 and fitted up to the pattern. While in this position the outer edges are 
 dressed ofif to conform to the outer edge of the flange of the frame, 
 also the longitudinal and cross center lines are laid out, as the plates 
 must meet at these points. One of the quarter plates is illustrated in 
 Fig. 35. 
 
 These plates are gotten out in four pieces by punching and 
 chipping to the outline of the templet, after which they are secured to 
 the flanges of the side frames of the machine with countersunk head 
 screws. 
 
 The center line of the pattern is next carefully tried for exactness 
 and the templet for drilling the flask pin holes applied. This operation 
 should be very carefully conducted, as the matching up of the cope and 
 drag portions depends entirely upon the care with which it is per- 
 formed. 
 
 Should a wooden stripping plate be desired, material equivalent 
 in length and width to the top of the side frame flanges ma}- be 
 cleated together in a temporary manner and the pattern placed in its 
 correct position upon it. With a small pair of dividers set to about 
 1-16-inch a parallel line is next scribed around the pattern. The cleates 
 are then removed and the material enclosed by the scribed lines sawed 
 out. Permanent cleates are next applied and the whole secured to- 
 gether. To protect the edge of the opening and to insure a closer 
 joint around the pattern without a large bearing surface, 1 3^ -inch by 
 ^-inch band iron is laid in around the opening, as shown in the plan 
 and elevation, Fig. 36. 
 
 The pattern having been secured to the machine, the plate or top 
 is set down over it and secured to the side frames with bolts. Plates 
 containing holes to receive the flask pins are now located by the aid of 
 the flask pin templet as previously stated, these plates being let down 
 flush with the top surface and secured with screws as shown. 
 
 With the machine fitted up, our attention is next given to the 
 matching up of the cope and drag portions of the mold. The most 
 satisfactory manner of ascertaining this fact and detecting any dis- 
 crepancy is to have two or three castings made and check them up 
 carefully. The making and checking of one casting is not always 
 reliable, as a little variation in the flask pins may make it appear as 
 if the setting up of the machine was not correct. 
 
 The drag portion of this pattern is mounted upon a roll-over 
 machine, that is, a machine which is inverted with the flask in place 
 
28-V 
 
 REP RESENT A TIVE PA TTERXS 
 
 and the pattern subsequently drawn up out of the sand, this being- 
 necessary on account of the fact that no bars are used in the drag 
 fiask and hence it cannot be Ufted off and rolled over. The attaching 
 of the flask to the machine of course changes the center of gravity of 
 the machine. For this reason two trunnions are required, as shown 
 at the right of Fig. 34, the fixed trunnion M being employed when in- 
 verting the machine with the flask attached, while the attachable trun- 
 nion, N, which is secured to the end frame with a pin and socket, as 
 shown, is used in returning the machine to its upright position when 
 the flask has been detached. 
 
 c 
 
 -^ y^ 
 
 
 / 
 
 
 
 7 
 
 _^ 
 
 
 5^ 
 
 ■^ 
 
 L 
 
 
 - 
 
 
 ^?;i;-.^Cx 
 
 Section H-M 
 
 Section G-G 
 
 Fig, 40. Core Box for Forminfr Core B 
 
 Everything being in readiness we will now proceed with the mold- 
 ing of the drag portion of the pattern. The pattern is first raised and 
 locked in position as shown in Fig. 34. The flask is placed on and 
 securely clamped down to the flange of the machine, a thickness of 
 prepared sand is applied over and tucked around the pattern. The 
 balance of the flask is filled with heap sand, which is rammed in, the 
 top being struck off in the usual manner. A bottom board is next 
 applied and clamped down, and this is followed by the rolling over 
 of the machine and the drawing of the pattern as previously described. 
 
 The next operation is the setting of the several dry sand cores 
 which form the metal thickness or bottom member of the bolster. 
 Before proceeding further it will be well to study Fig. 37, which 
 shows the manner -in which these different cores are placed together 
 
STEEL TRUCK BOLSTERS 
 
 29-V 
 
 in the mold. In setting the cores, the cores A, which form the two 
 oblong openingfs in the bottom of the bolster, are first placed in the 
 depressions left vacant by their respective core prints J. 
 
 It will be observed that these two core prints J are provided with 
 projections P, which might be termed dowels. These serve to locate 
 and secure the center core B in its correct position and also one end 
 of each of the cores C, the outer ends of the latter mentioned cores 
 being received by core print settings as shown. 
 
 When these five cores have been located, the holding-down cores 
 E are placed in position, directly underneath or opposite the depres- 
 sions in the cope pattern which form the openings in the top members 
 of the bolster, as shown in the cross section of the mold on the line 
 L-L, Fig. Z7. 
 
 Section t/'-iT" 
 
 Fig. 41. Core Box for Forming Core C 
 
 These two cores E are rammed up in the green sand core and 
 are used to prevent the dry sand cores at the bottom from rising, due 
 to the pressure of the metal exerted underneath the cores as the mold is 
 poured. 
 
 The method of ramming up the green sand core is illustrated in 
 Fig. 38. It will be noticed that there is a frame used for ramming up 
 the green sand core, the construction being made clear by the illus- 
 tration. The center part O which contains the center post and vertical 
 ribs of the bolster is made detachable and secured to the frame with 
 dowels, this being done to allow this part to be drawn first, so that 
 the top of the green sand core may be slicked and dressed up before 
 removing the frame proper. The core is rammed up as follows: 
 
30-V REPRESENTATIVE PATTERNS 
 
 After the dry sand cores are set, as already explained, the frame 
 without the center, Q, is lowered into the mold so as to rest upon the 
 parting. The material R passes down into the space between the wall 
 of the mold and the dry sand cores as shown by the dotted lines in 
 Fig. 37, thus closing up this space and preventing any sand falling 
 into it during the ramming up of the green sand core. The center 
 part O of the frame containing the center post, etc., which passes 
 down into the depression in the core B is also located. 
 
 The depression in the core B is formed by the material in the 
 core box shown in Fig. 40. The openings U, Fig. 38, are to facilitate 
 the ramming of the sand underneath the top portion of the frame. 
 After the sand has been rammed into the green sand core frame the 
 top portion Q is removed, the surface slicked up, and then the other 
 portions drawn away so as to leave the green sand core in place. 
 
 As the molding of the cope pattern shown in Fig. 33 is of a 
 simple nature and embraces no special points of interest, we will 
 proceed to discuss the construction of the core box employed in form- 
 ing the various cores. Fig. 39 shows a plan and cross section of the 
 core box used in forming core A, which gives its construction and the 
 manner of parting. In Fig. 40 is illustrated a plan longitudinal and 
 cross section of the core box used in forming the center core B. It 
 is in this box that the portion of the center post, with its ribs, is formed 
 by the material S, the remaining portion being made up in the green 
 sand core as explained previously. Within this box is also placed a 
 portion of the reinforcement around the oblong opening, the remain- 
 ing portion being placed in the core box shown in the plan and cross 
 section in Fig. 41. This latter box is employed in forming the two 
 end cores C, which are identical, with the exception of the runner T, 
 which is rammed up in one core only. The center pin core D, the 
 holding-down cores E, and the side bearing cores F are formed in 
 their respective core boxes, as shown in Figs. 42, 43 and 44. 
 
CYLINDRICAL CASTINGS 
 CHAPTER VI 
 
 RIG FOR PRODUCING CYLINDRICAL CASTINGS 
 
 31-V 
 
 The mold for a cylindrical casting like that shown in Fig. 45, may 
 be produced without the use of complete patterns or sweeps, as de- 
 scribed in this chapter. The parallel portion of the cylindrical body 
 is made with a cast iron ring similar to the ring used in molding 
 
 Fig. 45. Cylindrical Casting 
 
 pulley rims. While this method of drawing up a ring to produce a 
 pulley rim or other cylindrical shell is not new by any means, it may be 
 of interest to some and serve to show how this manner of molding can 
 be applied to different pieces. 
 
 A section of the mold is shown in Fig. 46. In beginning this it is 
 
32-V 
 
 REPRESENT A Til 'E PA TTERNS 
 
 at first necessary to dig a pit having a depth about equal to the length 
 of the desired casting and of such diameter that it will allow a molder 
 to work around the outside of the rim when ramming it up. A level 
 bed is then struck ofif in the bottom of the pit and a good substantial 
 
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 VENT VENT^, 
 
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 Mm 
 
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 sMiillS 
 
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 ^////(///((i(miii',')iu'i',(iiif 
 
 Fig. 46. Section of the Mold 
 
 stake driven in the center of the same. The stake should be of such a 
 length that that portion projecting above the bed will be equivalent 
 to the length of the desired casting. The distances A and B from the 
 
CYLINDRICAL CASTINGS 
 
 33-V 
 
 top of the stake to the under side of the cores forming the top and 
 middle flanges, is then scribed around the stake as a gauge for drawing 
 the ring to these heights, which correspond to points at which beds 
 must be struck off to receive these cores. 
 
 A cast iron ring of the required diameter and thickness and having 
 a width or face of 6 or 8 inches is then placed upon the bed with the 
 stake about in the center. A number of round sticks 12 or 14 inches 
 in length are then driven around the inside to form the vents shown 
 in Fig. 46. The inside of the ring should then be rammed up for 
 several inches so as to insure its remaining in the required position. 
 The cores C forming the lower flange are now set up to the ring and 
 the outside and the inside firmly rammed to the top of the ring. This 
 portion of the mold is then thoroughl}^ vented and the ring and vent 
 
 LOOSE IN BOX 
 
 Fig. 47. Core Box for the Trunnions 
 
 Stakes drawn up several inches. The operations of ramming and vent- 
 ing are repeated. During these operations some iron rods or core 
 irons should be set inside of the ring to hold the central portion of the 
 mold or green sand core in place. These would be parallel with the 
 rods forming the vents shown in Fig. 46. A spirit level should be 
 used on the upper edge of the ring during each drawing to insure a 
 straight and even casting. This process of ramming and drawing the 
 ring is continued until the top of the ring comes in line with the gauge 
 mark or line on the stake representing the under side of the cores D 
 used to form the middle flange and trunnions. 
 
 At this point, when the outside has been rammed, a level bed or 
 seat is struck off at the top of the ring, the ring drawn up as before 
 and the cores D set on top of the bed and in contact with the ring. 
 These cores should be pasted together before being placed in the mold. 
 After the cores D are in position the ramming and drawing is con- 
 tinued until the under side of the upper flange cores C is reached, 
 as indicated by the mark on the stake at the distance A from its top. 
 The ring is then drawn to the level of the bottom of these cores and a 
 bed struck off at this point to ue used for setting the cores C. 
 
34-V 
 
 REPRESENTATIVE PATTERNS 
 
 After the cores C are in place the ring is drawn up so that its 
 upper surface is level with the top of the required casting and a joint 
 or bed struck off for setting the covering cores E. The ring is then 
 drawn several inches higher, and the inside of the mold rammed up as 
 shown. The ring and vent sticks are then drawn out, and the covering 
 cores E, placed in position on top of the cores C, care having been 
 
 SECTION A-A 
 Fig. 48. Casting for Strainer Tank 
 
 -A— 
 
 taken first to file or cut the necessary gates in the cores E. A runner 
 is formed on top of the cores E as shown, and weights placed over the 
 outer portion of the cores E to hold them in position. The necessary 
 pouring basin is then formed in connection with the runner on top of 
 the cores E, when the mold will be ready to cast. 
 
CYLINDRICAL CASTINGS 
 
 35-V 
 
 The core box for forming the cores D is shown in Fig. 47, and a 
 similar core box without the trunnion pattern is used for forming the 
 cores C. 
 
 During this work care must be taken to see that the sticks for 
 forming the vents are drawn up at each ramming as, if they are left in 
 the mold too long, considerable difficulty will be experienced in draw- 
 ing them. On account of the fact that comparatively thin courses are 
 rammed at a time, that is, from 4 to 5 inches, it is not necessary to have 
 the ring pattern over 6 or 7 inches wide, and in most cases, any 
 
 Fig. 49. Sweeping the Bed 
 
 additional width beyond this is entirely unnecessary, as it only adds 
 to the difficulty of drawing the pattern if too great a width of it be 
 rammed up at one time. In case no ring pattern is in stock, it would 
 be necessary for the patternmaker to build up a ring of segments, turn 
 up a wooden pattern with the necessary finish on all faces and have a 
 casting made from which the iron ring pattern can be turned up in 
 the machine shop. 
 
 A somewhat more intricate casting of the above mentioned type 
 
36-\- 
 
 REPRESEXTATIl 'E PAl'TERXS 
 
 is shown in Fig. 48. It will be noticed that this has an internal 
 bottom flange, four cast feet, an external top flange, and a pair of 
 ears. The casting is to be used as a filter, or strainer tank. 
 
 The method of proceeding with the work is shown in Figs. 49 
 and 50. It is first necessary to strike off a level bed and in the center 
 of it drive a stake containing the dowel pin C, Fig. 49. To this dowel 
 pin is attached the sweep B, the striking edge of which contains the 
 form of the under-side of the feet. By revolving the sweep about 
 the stake a bed is struck off as shown. The dowel pin C is then re- 
 moved from the top of the stake and right-angle lines are drawn 
 
 Fig. 50. Section of Mold 
 
 from the center of the stake across the bed to locate the four cores 
 D, which arc made in halves and pasted together. These cores are 
 placed in their correct position against the swept surface of the bed. 
 To prevent the weight of the cast iron ring pattern from being born 
 entirely by the foot cores D, four pieces of bar or rod iron are 
 driven into the bed as indicated at E. These rods, however, should 
 be placed half way between the cores D. 
 
 The sweep stake is now removed, and in its place is firmly driven 
 the long stake as shown by the dotted lines, Fig. 49, and the full lines 
 
CYLINDRICAL CASTINGS 37-V 
 
 in Fig. 50. This stake extends up to the level of the under-side of 
 the top flange of the casting. As in the previous example, the distance 
 F is marked ofif on the stake to locate the under side of the cores H, 
 which serve to form the lifting ears. The cast iron ring jM, of the 
 required inside and outside diameter and having a face of about 8 
 inches, is placed in position, being supported by the rods E and the 
 cores D. They should be tested with the spirit level. 
 
 As in the previous example a number of one-inch pins about 16 
 inches long should be driven down into the bed at various points to 
 form vents. The first section of the flask is then placed into position 
 and staked down as shown in Fig. 50, after which the operation of 
 ramming is proceeded with. The outside is rammed first to the 
 height of 2 or 3 inches above the lower edge of the ring, care being 
 taken to see that the ring is not rammed out of place. 
 
 Any sand that may have been rammed under the ring and into 
 the inside of the mold is then removed, and the cores G, which form 
 the internal flange at the bottom are set into position, and the rods N 
 are driven into the bed back of them. The inside and outside are 
 then rammed up to the height of 5 or 6 inches, a vent wire being used 
 between the vent sticks. The ring and vent sticks are then drawn up 
 several inches, the operation of ramming and vented repeated, care 
 being taken to see that the green sand core is well rodded. 
 
 The spirit level should be used on the upper edge of the ring 
 during each drawing operation to insure a straight and even casting. 
 The process of ramming and drawing the ring and vent sticks is 
 continued until the top of the ring comes in line with the gage line 
 marked on the stake representing the under-side ear cores H. At 
 this point the outside is rammed up and a level bed struck ofif at the 
 top of the ring as shown in the dotted lines. Fig. 50. The ring is 
 then drawn up in line with the top of the stake, the ear cores H set 
 in position against the ring and diametrically against each other. The 
 operations of ramming, venting and drawing the rods, together with 
 the introduction of the iron rods necessary for supporting the core 
 are continued to the top of the ring and cores H, at which point the 
 bed is struck off to receive the flange core J. These are then set in 
 place and backed up with sand to the top of the flask, as shown in Fig. 
 50. The forming of the pouring basin and risers and the weighing of 
 the cores J, completes the mold. 
 
 The core boxes for forming the four dififerent cores are shown 
 in Figs. 51, 52, 53 and 54. Fig. 51 shows the box used in forming 
 one-half the foot core, an opposite hand piece ^1 being required in the 
 box to form the other half of core. Fig. 52 shows the box for forming 
 
38-V 
 
 REPRESENTATIJ'E PATTERNS 
 
 one half the Hfting ear core, which also requires an opposite hand 
 piece N for the other half. Figs. 53 and 54 show the frames employed 
 in forming the upper tiange core J and the lower internal flange core G. 
 The ring casting can be made with the aid of a segment pattern attached 
 to a stake, and subsequently turned to dimensions. 
 
 Fig. 51 
 
 Fig. 52 
 
 Fig. 54 
 
 Fig. 51. Core Box for Feet. Fig. 52. Core Box for Lifting Ears 
 Fig. 53. Core Box for Upper Flange Core. Fig. 54. Core Box for Internal Flange Core 
 
A NOZZLE PATTERN 39-V 
 
 CHAPTER VII 
 
 SKELETON PATTERNS 
 
 As the building of a complete pattern for large irregular cast- 
 ings such as nozzles, saddles, etc., is not always practical, the form of 
 pattern commonly known as skeleton or frame pattern is resorted to. 
 
 Fig, 55. Cast Steel Nozzle 
 
 This practically consists in the construction of a skeleton or frame, 
 the interior and exterior form and the thickness of which correspond 
 to the required casting. The pattern work can be made more or less 
 elaborate, according to the manner in which the molder desires to 
 proceed in the construction of the mold, and upon the ability of this 
 
AO-Y 
 
 REPRESENTATIVE PATTERNS 
 
 individual tlie evenness of the casting to a great extent depends, as the 
 skeleton gives an outline only and a partial guide for the strikes. 
 
 Three views of one section of a cast steel nozzle weighing about 
 19,000 pounds are shown in Fig. 55, two of these castings being bolted 
 together at A and subsequently riveted to the shell. While there may 
 be several ways in which a skeleton pattern for a casting of this de- 
 scription may be constructed, the one under discussion has proved 
 very satisfactory. 
 
 The completed skeleton is shown in the reverse position to that 
 in which it is built and cast in Fig. 56. The contraction of steel cast- 
 
 Fig-. 56. Skeleton Nozzle PattiTn 
 
 ings of this description and size is uncertain, and in most cases they 
 will not contract, the usual allowance of 3-16 per foot, hence, an allow- 
 ance of % of an inch per foot, with an extra allowance for finish for 
 exact dimensions will eenerallv be found sufficient. 
 
 Construction of the Skeleton 
 
 Following the general practice of laying out the required full size 
 sections, the building of the concave tlange B is the first part of the 
 work to be undertaken. To facilitate this operation, a form can be 
 lagged up as shown in Fig. 57, conforming to the concave surface of 
 the flange and upon which the flange is laid out and built, one quarter 
 at a time. The segments for the flange are fitted, dressed to thickness 
 
A NOZZLE PATTERN 
 
 41-V 
 
 separately and then tongued together as shown. A number of forms 
 as shown in Fig. 58 are next gotten out and Uned and leveled up on the 
 floor, taking care to see that they are securely braced. The four 
 quarters of the flange B are located and fitted together over these forms 
 and secured to one another. 
 
 To facilitate the handling and storing of the pattern, if desired a 
 joint can be made on the lines C C, Fig. 55. and the two halves 
 screwed together. 
 
 The ring D. Fig. 56. forming a part of the skeleton and to which 
 the ribs are secured is built up of segments turned to size and then 
 
 Fig. 57. Form for Base Flangre 
 
 elevated and secured with suitable supports and braces in its proper 
 relation to flange B. 
 
 It is next necessary to space off and locate the ribs. To facilitate 
 the cutting out of the ribs, material about Js of an inch thick can be 
 used, each piece being fitted in place and gotten out as a templet antl 
 later when the templets have been dressed to form they are reinforced 
 on both sides for strength and replaced in position as ribs. This 
 method results in a saving, both of material and time. 
 
 As the only sections shown by the draftsman are those illustrated 
 in Fig. 55, it becomes necessary without developing the section at 
 each rib, to work from one section to another. The templets for one- 
 half of each end are gotten out with the outer edges, sawed roughly to 
 form. They are then placed in position and temporarily secured, when 
 
42- V 
 
 REPRESENTATIVE PATTERNS 
 
 with the aid of a flexible strip and the eye the outer edge of each tem- 
 plet is dressed to form, working from one section to the other. The 
 templets for the opposite half of the end are now marked from those 
 already made and tried in place. The templets are then reinforced for 
 the proper thickness, after which the metal thickness or interior form 
 of the skeleton is laid off on each rib and they are dressed to the proper 
 thickness. They are then returned to place and secured in position. 
 It will be observed that no. provision is made on the skeleton for the 
 flange E, Fig. 55, this flange being made up during the molding opera- 
 tion by using a segment. 
 
 Fig. 58. Form to Support Pattern 
 
 Making the Mold 
 
 A hole is first dug in the floor to the required depth and two 
 of the forms shown in Fig. 58 which were used for supporting the 
 skeleton while it was being built are used for striking up a bed upon 
 
 COVERING CORE 
 
 Fig. 59. Section of Nozzle Mold 
 
 which the skeleton may rest. The forms are then removed and the 
 skeleton set in position upon the bed. The core is then rammed up. 
 To facilitate this operation and to prevent the sand from ramming out 
 through the openings, boards can be set up to the openings and 
 braced from the walls of the pit. 
 
 The gates are arranged as shown in Fig. 59, and the runner pre- 
 pared as the ramming progresses. After the core has been rammed 
 up the boards surrounding it are removed and the core or body of 
 sand dressed and slicked to the shape of the outside of the skeleton. 
 The exact form and evenness of surface will depend to a large extent 
 
A NOZZLE PATTERN 
 
 43-V 
 
 upoji the molder's ability and judgment. The cope or cheek is then 
 rammed up upon tJiis outer surface. In order to do this, the parting 
 is prepared, the flask placed in position and rammed up in the ordinary 
 manner. The depression forming the upper flange E being made with 
 
 the aid of a segment representing a section of the flange and at the 
 same time a seat for the covering cores is swept off on each side of the 
 segment. The cope or cheek is now lifted off, blocked up and finished 
 in the usual manner. 
 
44-V 
 
 REPRESENT ATI]- E PATTERNS 
 
 The sand between the ribs of the skeleton which represents the 
 metal thickness of the casting is now removed from the core and the 
 skeleton lifted off. The accompanying half tone, Fig. 60, shows a 
 
 Fig. 61. Double Nozzle Casting 
 
 view of the mold at this stage. The core is now dressed to form, after 
 which it is dried. The various parts of the mold are next assembled, 
 the cope or cheek lowered into place, the covering cores to form the 
 
 Fig. 62. Skeleton Pattern for a Double Nozzle 
 
 upper face of the flange E set, and risers prepared, and the space be- 
 tween the walls of the pit and the flask firmly rammed with sand. The 
 mold is then weighted down ready for pouring. A cross section of 
 the complete mold is shown in Fig. 59. 
 
A NOZZLE PATTERN 
 
 45-V 
 
 A Double Nozzle Pattern 
 
 Three views of a steel casting for a double nozzle as shown in 
 Fig. 61. This differs considerably from the one already shown and 
 brings out some different principles in molding. A plan of the 
 nozzle is shown in the upper right hand corner. A section on the 
 line A-A, is shown at the left, and a section on the line B-B at the 
 bottom. The pattern is parted upon the line B-B. A view of the 
 completed pattern in the position in which it is built is shown in Fig. 62. 
 
 In building the pattern the required sections are first laid out full 
 size. The building of this skeleton is similar to the pattern already de- 
 scribed. The lower flange G is gotten out and built up over a form. 
 The two upper flanges H-H are built up and turned with the lower half 
 left loose, so that these two half flanges may be drawn separately. 
 The rings I are secured by supports and braces in their proper relation- 
 ship to the flange G, after which the ribbing of the skeleton is pro- 
 
 Fig. 63. Section of Mold for Double Nozzle 
 
 ceeded with. To assist in getting out the ribs forming the parting of 
 the skeleton, a form ma}' be lagged up corresponding to the parting, 
 the outline of the rib laid out upon this convex surface and the rib built 
 up in segments. After one rib has been built in this way, the one 
 on the opposite side of the parting may be made to fit it. The location 
 and building of the other ribs is similar to that already described. 
 
 Making the Mold 
 
 The molding of this skeleton differs from the one previously de- 
 scribed in as much as it is cast upon its side, and with the aid of a 
 core bar the core or inside is lifted out. This necessitates the prepara- 
 
46-V REPRESENTATIVE PATTERNS 
 
 tion of a seat for locating and supporting the core when it is returned 
 to the mold. A hole is first dug to the required depth and the drag 
 half of the pattern is bedded in to the thickness of the ribs. The inside 
 is then slicked and dressed to form and the seat for the core prepared 
 as shown in the cross section of the mold, Fig. 63. 
 
 The core bar is next placed in position and the drag half of the 
 core rammed up. The parting outside of the skeleton is prepared 
 and the cope half of the skeleton placed in position , after which the 
 ramming of the interior is proceeded with. 
 
 Owing to the angle on which the flanges are set, the faces of 
 the flanges from the parting line down are formed by the core as shown 
 in the cross section of the mold in Fig. 63. In other words, as far as 
 this portion of the flange is concerned, the core forms an intermediate 
 part for the mold. When the core is lifted out, the lower portion of the 
 flanges are exposed and left free to be drawn. 
 
 When the ramming of the upper half of the core for the interior 
 of the skeleton is completed, this portion of the skeleton is lifted off 
 and the core slicked and dressed and paper applied, after which the 
 skeleton is returned and the openings between the skeleton filled with 
 sand and slicked off so that it will form a body upon which the cope 
 is rammed in the usual manner. When the cope is completed, it is 
 lifted off, together with the cope half of the skeleton. The cope is 
 then blocked up, the sand between the ribs removed and the half of the 
 skeleton pattern drawn. 
 
 With the aid of the core bar, the core is then lifted out, blocked 
 up, and the sand between the ribs of the lower or drag half of the 
 skeleton removed and the skeleton lifted out. The drag portion of 
 the mold is then finished, the runner and risers are prepared during 
 the ramming up of the mold. The mold and the core are then dried 
 assembled, and prepared for pouring in the usual manner. 
 
A CHILIAN MILL MORTAR 
 CHAPTER VIII 
 
 47-V 
 
 PATTERN FOR A CHILIAN MILL MORTAR 
 
 Several views and sections of the casting to be made are shown 
 in Figs. 64, 65, 66, 67 and 68. In Fig. 64 there is given a half plan 
 and sectional plan on the line AAA, Fig. 67, which shows the upright 
 members of the casting located between the screen openings, together 
 with the wedge chucks B and C. These wedge chucks are used for 
 wedging or securing the screens in place. Fig. 65 shows the bottom 
 
 SECTION AT A-A-A 
 Fig. 64. Plan of Chilian Mill Mortar 
 
 or inverted plan of the mortar, while Fig. 66 gives a side elevation, 
 and Fig. 67 a longitudinal section of the mortar taken on the center 
 line DD, Figs. 64 and 65. This section, with the radial sections shown 
 in Fig. 68, which are taken on the lines EE, FF and GG, Fig. 64, 
 should receive careful attention in order that the construction and 
 molding of the pattern may be more readily understood. It is from 
 
i8-V 
 
 REPRESENTATIVE PATTERNS 
 
 these four sections that the pitch of the trough is obtained and the 
 laying out of which will be described during the construction of the 
 pattern. 
 
 Of course a full size working lay-out is essential for reasons well- 
 known. The sectional lay-out should be taken through the center of 
 the mortar as shown in Vig. 67, and this view will also serve for laying 
 out the trough, etc. A lay-out of the plan is also required, but as the 
 mortar is symmetrical about the center line DD, Fig. 64, a half plan 
 lay-out is all that is required. 
 
 Fig-. 65. Bottom of Mortar 
 
 Construction of the Pattern 
 
 While a mortar pattern of the design shown is not of a particularly 
 intricate nature it nevertheless contains some very good features in 
 patternmaking and also in molding. The writer has made a number of 
 mortar patterns of this general type in the manner described and this 
 method of constructing the pattern as shown has been found to give 
 a durable pattern and at the same time is as economical in time and 
 material as could be desired. 
 
A CHILIAN MILL MORTAR 
 
 49-V 
 
 The upper view in Fig. 69 shows a longitudinal section of the 
 assembled pattern taken on the center line DD, Fig. 64. This section 
 should give a fairly good idea as to how and where the various parts 
 of the pattern are joined and fitted together. While all of the partings 
 
 Trough 
 
 Fig. 66. Side Elevation of Mortar 
 
 shown are not essential or required in molding they nevertheless facil- 
 itate the drawing and also tend to prolong the life of the pattern, on 
 account of the fact that the different parts can be removed from the 
 sand separately and with less rapping as the dressing of the mold pro- 
 ceeds. 
 
 SECT/ON D-D 
 Fig. 67. Longitudinal Sectioh of Mortar 
 
 Another advantage in constructing the pattern in sections is that 
 it is easier to handle and store. This sectional construction also affords 
 protection to the hopper sections, \\hich is of rather light and frail 
 construction. 
 
 Shown at the left in the upper view of Fig. 69 can be seen one 
 of the wedge chucks B. By studying a section of one of these chucks 
 as shown in Fig. 64 it will be seen tliat it v.'ould be necessary to core 
 out the slots and if this were done with a dry sand core it would neces- 
 
50-V REPRESEXTATirE PATTERNS 
 
 sitate a troublesome core setting, as it would come on the parting line 
 of the drag and cheek portions of the mold. To avoid this objection- 
 able feature this part of the pattern was arranged as shown by a section 
 of the chuck at the upper left hand corner of Fig. 69. This has over- 
 come the difficulty very satisfactorily, as the arrangement allows the 
 two ears to be drawn in and the dry sand core set in place to form 
 the outline of the back of the chuck as indicated by the dotted lines. 
 Wedge chuck C is shown to the right in the figure and the manner of 
 coring out the slot is self-explanatory. 
 
 Shown at the bottom of Fig. 69 are the four separate sections 
 or parts that form the body or center of the pattern, arranged in the 
 order in which they are placed together. In beginning the building 
 and turning up of the parts the center portion H receives attention 
 first. This part can be built up on the face plate of the lathe some- 
 what after the manner and in the position shown. This is followed 
 by the turning of the face, wi'ih its two offsets I and J. Offset I 
 
 SECTIONS E-E F-F C-G 
 
 Fig. 68. Sections of Rim of Mortar 
 
 receives and locates the lower rail K of the hopper, while offset J 
 locates the center or conical portion L of the pattern. 
 
 The most convenient manner of disposing of the two parts K 
 and L is to build them up and turn them in position upon part H, as 
 shown bv the dotted lines. It will be seen that all that is necessary is 
 to fit the first course of segments in their respective offsets, pin and 
 screw them in place, taking care to leave the heads of the screws 
 exposed so that they may be removed and then proceed with the 
 building up and turn in in the usual manner. 
 
 At the completion of the two members they are removed and part 
 H rechucked so that it can be turned on the outer diameter and back. 
 During this turning the offset M'is formed to receive the core print 
 N, as shown. The hub O is of course turned independently and fitted 
 in place during the turning of the portion L. 
 
 Our attention is next given to the upper rail O of the hopper 
 which is built up and turned as shown. 
 
 The center lines and widths of the five standards P are next 
 
A CHILIAN MILL MORTAR 
 
 51-V 
 
 laid off on both rails K and O, the rails are then cut out to receive 
 the standards and the latter portions secured in place as shown. After 
 fitting on of the wedge chucks B and C, the building up of the trough 
 which is shown in plan and section in Fig. 70 next takes our attention. 
 
 Loose Dowels 
 
 Joint in Pat 
 
 CROSS SECTION OF ASSEMBLED PATTERN 
 
 HALF ELEVATION 
 
 HALF SECTION 
 
 HALF SIDE ELEVATION HALF SECTION 
 
 Fig. 69. Details of Construction of the Pattern 
 
 This figure shows a half plan and longitudinal section through the 
 center on the line DD, also radial sections on the lines EE, FF and GG. 
 These latter sections serve to illustrate the general construction of the 
 pattern. By studying the figure it will be observed that the pitch of 
 
52-V 
 
 REPRESENTATIVE PATTERNS 
 
 the trough is not regular, as is the usual practice in the designing of 
 mortars of this type, that is, it does not have a uniform pitch or drop 
 from back to front, which would, of course, bring the bottom of the 
 trough always in the same plane. In the case under discussion the 
 
 Fig. 70. Construction of the Trougrh 
 
 pitch of the trough varies, the amount of pitch or drop being given 
 at four stations, S, T, U and V, at the center of the trough, as shown 
 by the radius X, the pitch being decreased toward the apron. 
 
A CHILIAN MILL MORTAR 
 
 53-V 
 
 In the lower part of Fig. 70 Is shown one way in which the trough 
 may be laid off and built in position up to the body portion of the 
 pattern. This manner of constructing the trough will be found about 
 as convenient as any other method. The five stringers, AA, BB, CC, 
 etc., representing the five stations of the drop or pitch of the trough, 
 are first gotten out and dressed to the required height of the under- 
 side of the trough as shown. They are next secured to the work table 
 in their respective positions and-their proper relationship one to another 
 and also to the body of the pattern, which is placed in position and 
 secured temporarily as shown. 
 
 SECTION J.J 
 Fig. 71. Core Box 
 
 The segments or material FF, which is to form the bottom of 
 the trough are next gotten out roughly to size and of ample thickness 
 and width to allow for sawing and dressing to form. In length the 
 material FF is gotten out equal to the distance between stations, at 
 which points it is butted together as in segment work and temporarily 
 bradded down. 
 
 Next, with the trammels so arranged that one point will extend 
 down over the center portion, H into the center of the trough, the 
 
54-V REPRESENTATIVE PATTERNS 
 
 center line of the trough or the radius X is scribed. The dififerent 
 widths at the bottom of the trough are now taken from their respective 
 layouts as shown in the upper ])art "of Fig. 70 and transferred to the 
 material as shown at AA, BB, CC, etc. This is followed by the sawing 
 of the segments to size. 
 
 The next work consists in the dressing ofif of the underside of the 
 segments from station to station so that the segments will conform to 
 the pitch. This is done carefully by the eye, and the exercise of a little 
 judgment is all that is necessary, as there is nothing of great impor- 
 tance attached to the trough and a slight variation one way or the 
 other will not make any material difference. 
 
 Having the underside of the material or segments worked to form, 
 it is next necessary to reduce them to the required thickness, which 
 is a verv simple operation. After this the segments are returned 
 and bradded in place. The lower part of Fig. 70 shows the work at 
 this stage of completion, ready to secure the segments, the positions of 
 which are indicated by the dotted lines. The first course of segments 
 at the inner and outer diameters of the trough must be applied to the 
 irregular surface, hence it will be necessary to chalk and fit them for 
 a glued joint. 
 
 After these two courses are fitted and glued in position their upper 
 faces can be joined straight, which will allow the remaining course 
 to be joined in the usual manner. If each co.urse of segments is care- 
 fully marked from the previous course, applied and sawed to line and 
 beveled, very little work will be required in dressing them to form. 
 
 As the first course applied forms the fillet, it will be necessary 
 to work this out with a gouge. It will be noticed that the first two 
 courses of segments which form the inner wall of the trough are fitted 
 up to part H of the pattern for about half of the distance around 
 the pattern from which point they extend or flair outward on to the 
 apron, as shown. 
 
 Before removing the work previous to dressing up the under sur- 
 faces holes should be bored for loose dowel pins to attach the trough 
 to the body of the pattern to facilitate the process of molding. 
 
 Next, the usual provisions for rapping and drawing the various 
 parts of the pattern must be made, the pattern finished with shellac, 
 etc., when our attention will be given to the construction of the core 
 box. 
 
 The core box necessary is shown in Fig. 71. The core made in 
 this box forms the interior of the conical center of the casting, as 
 
A CHILIAN MILL MORTAR 
 
 55-V 
 
 shown in the cross section of the completed mold, Fig. 72. The illus- 
 tration of the box shows its construction fully so that no detailed 
 description is necessary. 
 
 Molding 
 
 The manner of making the mold is clearly illustrated in Fig. 72. 
 As this section is taken at the center line of the mold the parting 
 appears about on a line with the joint of the flask. This fact would 
 not be the case at the right or left of the section shown, owing to 
 the pitch of the trough to the right and left of the line, upon which the 
 
 E 
 
 
 r 
 
 ^^ 
 
 '^^i.v 
 
 til 
 
 ■I'l^ 
 
 
 
 
 f('l>r 
 
 
 
 '; Vi^u- Jr 
 
 -r ^ 
 
 / 
 
 . K K 
 
 a 
 
 ^ V 
 
 
 ■ 
 
 
 flicrk : 
 
 
 
 
 \- . 
 
 ^ , 
 
 Fig. 72. Section of Mold for Mortar 
 
 section was taken. The parting would, of course, extend up into the 
 cope on one side and down into the cheek on the other. By inverting 
 the upper view in Fig. 69 the line of the parting can be easily followed. 
 In drawing the pattern from the sand the cope is lifted off first, 
 the trough portion of the pattern drawn out, and this permits the lifting 
 off of the cheek. The line of parting between the cheek and the interior 
 body of sand which forms the interior of the hopper is shown along the 
 lines KK. After the cheek has been removed the other sections of 
 the pattern can be withdrawn in their respective order and the mold 
 finished in the usual manner. 
 
56- V REPRESENTATIVE PATTERNS 
 
 CHAPTER IX 
 
 THE MAKING OF A CROOKED ELBOW 
 
 Life is made interesting for the patternmaker at times by the 
 various problems, meehanical, geometrical and otherwise, which are 
 presented to him for solution in the course of his daily duties. The 
 making of the elbow described in this Chapter presents a few of these. 
 
 This elbow was made to connect with a rectangular pipe 6x9 
 inches, which passed around a cylindrical body with a fiat, conical head 
 having an opening 7 inches in diameter. Metal thickness was specified 
 as 3-16 inch, but the patternmaker and the molder between them prob- 
 abl\' increased this a little by the process known as playing safe. The 
 variation, however, was not more than 1-16 of an inch, as weight was 
 an important item. 
 
 In producing a pattern of this character, or, in fact, in producing 
 anv pattern, the first consideration with the practical patternmaker is 
 the manner of molding it. Notwithstanding the opinion of our friends, 
 the molders, to the contrary, a goodly number of patternmakers are 
 wearing gray hairs (when they are not bald headed) from worrying 
 over this very question of the moldability (to use a newly coined word) 
 of patterns. 
 
 The elbow is shown as projected in the three views at the left of 
 Fig. 72) and the first thing to determine is just where or how to mark 
 the parting line in order to avoid waste of lumber in gluing up the 
 necessary block from which to make the pattern. The first piece should 
 be large enough to include all of the curved part of the pattern, the end 
 flanges and core prints being made separate, and as these latter are of 
 known shape and dimensions they are an easy proposition, and when 
 finished can be screwed to the main portion of the pattern. Lines A 
 and B, while not a true projection, will give the average patternmaker 
 a better idea of the method of parting this pattern than the projection 
 lines would. 
 
 The material being glued up for the several parts, the part for 
 the drag or lower half of the pattern is then cut to conform to the 
 parting line. To aid in this work free use should be made of the sur- 
 face table if you are fortunate enough to possess one, or a trued-up 
 board can be made to answer if no surface table is at hand. This 
 will result in a saving of both time and lumber, especially if the pattern- 
 maker can secure a surface gauge of sufficient size from his friend, 
 the machinist, for it is not likely that one will be found in the pattern 
 
58-V REPRESENTATIVE PATTERNS 
 
 shop equipment, though it should be there. By clamping the base of 
 the surface gauge to the table, it is easy to turn it into a sliding tram- 
 mel which can be raised or lowered at will and still keep the same 
 radii, the stem being set up perpendicular to the face of the board. 
 This makes it easy to lay out many lines, even on a rough surface, and 
 to do it in shorter time than can be done by projection. It is also 
 accurate. 
 
 You will notice that the parting line has to be twisted at the round 
 end of the ijattcrn in order to make it possible to place the core into 
 the mold in one piece and also to produce a pattern with as few loose 
 pieces as possible. It will be found easier to make this part from the 
 bottom of the slope (line C, Fig. 72)), separate and then set it to the 
 correct angle and screw it in position, after which the bevel from this 
 to the main line of parting can be worked out. This being done, the 
 upper or cope half of the pattern is then fitted to the lower half, form- 
 ing a complete joint, and the two doweled together. Xext, the form 
 of the pattern is laid out on the joint and the two parts are finished 
 together. In this work we must again depend upon the surface plate 
 to make sure that there is no back draft, care being taken to place the 
 pattern in exactly the same position each time it has to be removed from 
 the surface plate. 
 
 It is necessary that the flanges be loose from the body of the 
 pattern, on accovmt of the angle at which they are placed and the curve 
 that fits the cone. Otherwise it will not be possible to draw the pat- 
 tern. These loose pieces should be placed in a groove, in order to 
 insure their staying in position while ramming and also to give them 
 strength. The portion of the upper part of the pattern marked "loose 
 piece" should also be doweled on separately, as the angle of the end 
 is such as to prevent a straight draw. 
 
 In making the core box, the block for the lower half of which 
 is shown embedded in the sand, it is first necessary to make the block, 
 which is composed of three pieces for the body and two pieces to close 
 up the ends. These are screwed together and fitted at the joint to the 
 upper half of the pattern. This done the construction lines 1-1, 2-2, 
 Z-2>, etc., are marked on the pattern and transferred to the joint of the 
 core box. The outline of the pattern is also marked by a scratch awl 
 while it is lying in position upon the core box. Another line is then 
 made inside of this corresponding to the thickness of the metal. 
 
 Templets are next made of thin pieces of wood and fitted to the 
 pattern at the lines marked, and at as many additional places as the 
 patternmaker thinks necessary. From these other templets are made 
 for the core box, allowing the thickness of the metal between them, 
 
A CROOKED ELBOW 59-V 
 
 as shown in the upper right hand corner of Fig. 7Z, which illustrates 
 the templet for line 6-6 of the drag half of the pattern. 
 
 Before we proceed to cut out the core box, it is necessary that we 
 provide for the requisite core plates upon which to dry the core and 
 it is highly important that these be true to shape, as otherwise the 
 cores will not joint up and the results will be either too thick metal or 
 a defective casting from the cores cutting through where they should 
 not. As a simple method to insure the shape of these plates the writer 
 uses the block prepared for the core box as a follow board, as indicated 
 in the lower left hand corner of Fig. 7Z. Upon this were fitted two 
 pieces, say ^ inch to one inch wide, as an outline for the core plates, 
 these pieces being 5-16 inch thick. Between them sand was filled in and 
 swept off to the required thickness. This sand was then freely 
 sprinkled with parting sand and upon it placed ribs, as indicated. 
 These ribs are intended to bring the plate to a level bearing and also to 
 strengthen it and prevent its losing its shape from the heat of the core 
 oven. A flask was then placed over this and molded in the usual 
 manner, first ramming up and placing the bottom board, then rolling 
 over and making the cope half after lifting off the frame. The strips 
 are then removed and the sand lying between them removed, the ribs 
 drawn, and, except for the connecting gates, etc., we will have the 
 mold for the core plate for the lower core. The same method is used 
 for molding the core plate for the upper half. 
 
 We next proceed to cut out the core box, using the templets for 
 this purpose, put in the finishing touches, varnish, etc., when the job 
 is completed. 
 
SECTION VI 
 
 HINTS, SUGGESTIONS AND RIGS 
 
 CHAPTER I 
 CUTTING THE SCORE IN A CHAIN DRUM PATTERN 
 
 Frequently when a number of drums are required, the casting of 
 scored chain drums, as shown in Fig. 1, is resorted to; and when of 
 too small a diameter to sweep conveniently, a complete pattern is re- 
 quired, parted longitudinally through the center and molded likewise. 
 In some cases, particularly that of a coarse pitch, which requires the 
 pattern to be partially revolved while being drawn from the mold, as 
 
 6 
 
 > 
 
 1 '^ 
 
 4 
 3 
 
 1 
 
 Y 
 
 1 
 
 1 ,' 
 
 
 , • . , 
 
 »4 
 
 23 
 
 / , 1" 
 
 1 -' 
 
 
 I I ■ 
 
 
 FiK.2 
 
 Fig. I. Chain Drum. Fig. 2. Pattern for Chain Drum 
 
 the revolving of the pattern will cause it to travel forward in the mold, 
 a detachable core print may be placed at one end of the pattern, leaving 
 a depression into which the pattern may protrude while being drawn. 
 The barrel having been staved up in the ordinary manner, of ma- 
 terial of sufficient thickness to permit the cutting of score, it is placed 
 in the lathe and turned to the required outside diameter and the center 
 line of score marked ofif before removing it from the lathe centers, as 
 shown in Fig. 2. 
 
2-VI 
 
 SUGGESTIONS AND RIGS 
 
 One way in which the laying off of this center Une can be easily 
 accomplished is to locate the starting point of the score Y, and scribe 
 a line around the barrel as shown by XX, Fig. 2. Now from starting 
 point Y step off the circumference into any number of equal points, 
 and through these points draw longitudinal lines from end to end of 
 the barrel as shown. 
 
 The lead or pitch of the score or the lead or pitch of any screw 
 is the distance it would travel forward in one revolution. Hence, if 
 the circumference of the barrel be developed as shown by V, Fig. 3, 
 and a perpendicular line W be erected at one extremity, in height the 
 equivalent of lead or pitch of score, the line Z or the hypotenuse of 
 the right-angle triangle thus formed will be the angle of center line 
 of score about the barrel. 
 
 .11 I I I I' 
 
 3 4 5 7 » 9 10 11 1^ 13 14 11 l'.; 17 la n 20 -n •:L S.UJplT^h^f 
 ^V Cincumferenue ot Barrel — >1 Bcore 
 
 SECTION A-A 
 Fls.4 
 
 [?_ 
 
 .S.PJNDLE 
 
 rig,6 
 
 Fig. 3. Development of Score. Fig. 4. Cutter Head. Fig. 6. Cutter Spindle 
 
 Now if the developed circumference V be divided into the same 
 number of equal parts as the barrel, 1, 2, 3, 4, etc., the transferring of 
 this center line Z to the barrel becomes a simple operation, for by using 
 the line X scribed around the barrel at the starting point of score, Y, 
 Fig. 2, as the base line, V, of the developed circumference, Fig. 3, 
 with the dividers, transfer the distances 1, 2, 3, 4, etc., to the corre- 
 sponding longitudinal lines on the barrel. Then with a flexible rule 
 or strip connect these points, which will give the center line of the 
 score for one revolution, the continuation of which is very simple. 
 
 As a right or left-hand thread is confusing to some, a good point 
 to bear in mind is that a right-hand thread raises to the right and a 
 left-hand thread raises to the left ; or to observe the thread of an ordi- 
 nary wood screw, which is invariably a right-hand thread. If the 
 score is to be cut by hand, lav out the width of score from center line 
 
CUTTING THE SCORE IN A DRUM 
 
 3-VI 
 
 and proceed with back saw-gouge and templet. Any workman who 
 has worked out the scoring on a drum by this method has no doubt 
 found it a slow and tedious job. 
 
 Illustrated in Fig. 5 is an arrangement of lathe with a cutter 
 attached and the barrel so placed as to permit the cutting by power. 
 While the initial cost of fitting up the cutter, etc., should not exceed 
 six or seven dollars it would reduce the actual time of cutting to a 
 minimum, and would do the work at a cost below that of cutting by 
 hand a drum 30 inches in diameter and 54 inches long at SIjAc per 
 hour. 
 
 Fig. 5. Lathe Rigged to Cut Score 
 
 The spindle and cutter are shown in greater detail in Figs. 4 and 
 6, the cutter being turned to form and cut out as shown, and filed up 
 to form a cutting edge. A good, substantial block, A, having been 
 gotten out with slot cut out to receive guide E, and the top dressed 
 ofif to a sufficient angle, B, to bring the cutter in line or in the same 
 plane as that of the score of drum. The bracket C is now attached 
 and this arrangement secured to the lathe bed as shown, and in line 
 with a pulley, D, previously turned upon face plate. The center line 
 of score having been layed off on the barrel as previously described, 
 a portion of the score long enough to take in the cutter and guide E 
 
4-VI 
 
 SUGGESTIONS AND RIGS 
 
 is cut out by hand to exact templet. The shaft or spindle F, which 
 will be governed by what can be found around the machine shop or 
 the spindle used in the foundry, should be twice the length of the 
 barrel plus the width of supports G. The barrel-heads having been 
 cut out to receive the spindle, the barrel is placed upon the spindle, 
 set upon supports G and clamped down. 
 
 The barrel is now placed in position with the portion of the com- 
 pleted score opposite the cutter, which is now moved forward to its 
 correct position and secured, as is also the guide E, which must fit 
 the completed score snugly. The cutter, revolving in the direction 
 
 Fig. 7. Cutter on Back of Spindle 
 
 Fig. 8. End Mill Type of Cutter 
 
 indicated by arrow, is now set in motion, the barrel revolving toward 
 the cutter and upon spindle F, guide E, following the cut score, giving 
 the lead and forcing the barrel along the spindle. 
 
 To lessen the friction of the barrel and spindle a roller can be 
 adjusted underneath the barrel if necessary. Also, pieces can be 
 screwed to the end of the barrel to facilitate revolving. If the score 
 is very deep, a portion of the material may be removed and the score 
 completed with a second cut. 
 
 There is another way of getting out this work and it differs in 
 several respects from the one already described. The principal varia- 
 tions from the other plan are in the location of the barrel — which is 
 in a transverse position — and in the cutter which is of an entirely 
 different shape and is shown attached to the lathe spindle in Fig. 7. 
 The setting and handling of the barrel during the cutting operations 
 remain identical with the former arrangement. 
 
 The cutter is seen in greater detail in Fig. 8 and may be attached 
 to the lathe spindle as illustrated or it can be provided with a taper 
 shank to fit the center of the spindle. The cutter having been turned 
 to the required form and fitting the spindle, the sides A are milled off 
 
CUTTING THE SCORE IN A DRUM 5-VI 
 
 and the material at B removed by drilling — leaving the wall C of 
 about 5-32 of an inch in thickness. The cutter edges are then filed up, 
 tempered and whetted to a freely cutting condition. To overcome 
 the plain blunt surface D at the extreme point of the cutter and which 
 would not remove the stock, a small slot E is filed in it and this will 
 be found sufficient to remove any possibility of trouble. 
 
6-VI 
 
 SUGGESTIONS AND RIGS 
 CHAPTER II 
 
 A CORE BOX AND CLAMP COMBINED 
 
 A combined core box and clamp, which will be found convenient 
 and a time-saver where a number of cores are to be made, is shown 
 in Fig. 9. While the illustration may be self-explanatory, a few re- 
 marks will not be out of order. The central figure shows the plan 
 of an assembled rectangular core-frame, or box, with clamp in place. 
 To the left is shown the end view and the arrangement of wedges. A, 
 
 Fig. 9. Combined Core Box and Clamp 
 
 which are attached to the sides of frame, while the side view of box 
 is shown at the bottom. At the top and right is shown the bottom 
 board B. with clamp C attached, also stop D for locating the frame 
 on the bottom board. 
 
LATHE TOOLS 
 
 7-VI 
 
 CHAPTER III 
 SOME LATHE TOOLS 
 
 A number of lathe tools which shops equipped with screw feed 
 lathes are using, and which give very good results, are shown in 
 Fig. 10. 
 
 The roughing tool or gouge is shown at 1. The cutting edge 
 should slant downward somewhat as it approaches the end or tail, 
 to give a drawing cut, and the outside face ought to overhang at 
 least 10 degrees from a perpendicular all the way around, so as to 
 take hold nicely at the very edge, and not have any point of contact 
 below where it is doing work, to retard its action. An emery wheel 
 
 Fig. 10, Lathe Tools 
 
 about 8 inches in diameter gives a good concave to the outer face, 
 and when this tool has a few finishing touches with an oil stone, it 
 is surprising to see the heavy chips it will take from a rough piece 
 without even previously removing the corners. 
 
 The ordinary flat tool which can be ground round or pointed, as 
 indicated by the dotted lines, is shown at 2. 
 
 A boring tool is shown at 3, and there should be one right and 
 one left. I have used tools of this shape a great deal, and for deep 
 boring know of nothing better. They also work equally well on out- 
 side work and are especially useful when the piece being turned is 
 too large in diameter to slide the carriage along under it, for it can 
 be placed in the tool-post in such a manner as to overhang a long 
 distance and work clear to its limit. 
 
8-VI SUGGESTIOXS AXD RIGS 
 
 A nice tool for facing off segments and the surface of any disk 
 which may be on the face-plate is shown at 4. It works quite well 
 also when turning on the outside diameter, but is especially for facing. 
 
 The tool shown at 5 is known as the "arrow point" tool and is 
 used for finishing. It should be set slightly angling to the work. 
 When properly sharpened it will cut almost as smooth as glass, and 
 on straight work, like rolls, etc., it works as nearly perfect as one 
 could wish. The action, it will be noticed, is similar to a wood- 
 turner's skew chisel. 
 
 A cutting-off tool, which does not tear and scrape like the ones 
 generally used, that are flat on top, is illustrated at 6. It is intended 
 to be sharpened on an emery wheel, about 6 or 8 inches in diameter, 
 and then be touched up on an oil stone, as in fact are all of the tools 
 described. The curvature on the upper side of this tool allows it to 
 enter the work easily and take a fast cut, while the curve below re- 
 moves the stubbed end frequently seen on tools of this class. One 
 of these tools, made in every respect like No. 6, except with a wider 
 cutting face, is excellent for shouldering down on work. With it 
 a number of cuts can be made down to almost the diameter required, 
 then get the exact diameter, and finish by moving the carriage along. 
 The tools cut quite smoothly moved along in this manner, but not quite 
 as well as the "arrow point." 
 
 A boring tool which is useful in holes of small diameter where 
 the one shown at 3 camiot be conveniently operated is shown at 7. 
 
 A tool for general work, which is good for smoothing and 
 shouldering down, is illustrated at 8. It will be noticed that it has 
 two cutting edges which can be used, and the top is shaped by the 
 curve of the emery wheel something as in No. 6. The angle of the 
 point should be less than a right angle, as if so made the tool can be 
 set so as to be started in with the slide rest, and then be stopped and 
 moved along by the carriage. A much deeper chip can be taken with 
 this tool when the carriage is moved than with the one shown in No. 6, 
 as its action is more of a drawing cut. 
 
 A handy lathe dog which will be found convenient while turning 
 pieces in halves, avoiding the accustomed use of screws, is shown at 9. 
 
BALL TUR\UNG 
 
 CHAPTER IV 
 
 WOODEN BALL TURNING 
 
 9-VI 
 
 As patternmakers are frequently called upon to do work a little 
 outside of their regular line, I feel that the following may be found 
 useful to some. In turning a ball, first rough out as shown at the 
 bottom of Fig. 11, forming two, three or more balls per stick, as size 
 will permit. This turning should be done to within 1-16 of an inch 
 of the finished diameter, using an ordinary sheet metal templet of the 
 form shown in the upper right hand corner of Fig. 11. 
 
 ^Wood Chuck 
 
 Fig. 11. Bolt Turning 
 
 The balls are then sawed off and the unturned spots rounded over. 
 A chuck should be turned and backed out as shown in the upper left 
 hand corner of Fig. 11. This should receive the ball to within an 
 eighth or a quarter of an inch of its center line. 
 
 The ball is first placed in one position and the groove turned 
 around the center line about an eighth of an inch wide and to the re- 
 quired diameter, as shown in the illustration. The ball is then removed, 
 given a quarter of a turn and a small groove turned at right angles to 
 the first. All that now remains is to turn oft the surplus material be- 
 tween quarters formed by the grooves. The ball is then returned to its 
 original position and the other half finished. Chalking the inside of 
 the chuck will assist in holding the ball in position. 
 
10-VI SUGGLSTIOXS AXD RIGS 
 
 CHAPTER V 
 SHRINKAGE 
 
 All metals passinc: from the liquid to the solid state undergo ex- 
 pansion when in the j)lastic condition. It is this feature in the transi- 
 tion that enables the metal to take and retain the impressions of molds. 
 In cooling from the plastic condition to the solid state most metals 
 contract. The amount of this contraction in passing to a normal tem- 
 perature will vary for the different kinds of metals. Patterns have 
 therefore to be made larger than the desired casting by this amount. 
 Here comes the necessity on the part of the patternmaker for the use 
 of discreet judgment based upon extended experience in order to 
 obtain the best possible results ; different mixtures of iron as well as 
 alloys will contract varying amounts. Moreover, the varying propor- 
 tions of the castings will vary in the amount of contraction. An 
 extended and plain casting will contract dift'erently from one of more 
 compact form, though both may be of equal weight and cast at the 
 same time and of the same material. A heavy casting will contract 
 less than a light one, while a small casting will often come out as 
 large or even larger than the pattern. Hard metal will contract more 
 than soft metal, and the presence of large dried cores in a mold will 
 diminish or retard the contraction. A plain cylinder will contract less 
 in diameter than in length. 
 
 The contraction or shrink rule, as the name implies, is a rule that 
 is made longer than the standard measure by the amount which the 
 various metals will contract in cooling from the plastic to the solid 
 state. Though a standard rule is required for the measurement of 
 castings it would be obviously inconvenient to use it in patternmaking. 
 The workman would be perpetually making allowances for contraction 
 in fractional parts of an inch. So the shrinkage rule economizes his 
 time and insures something more accurate than approximations. 
 
 The conventional allowance for cast iron is 3-32 inch to the foot, 
 but this rule needs modifications in its application as already discussed. 
 Heavy bed plates, etc., are usually made with an allowance of 1-16 
 inch per foot, and sometimes with the standard rule. The contraction 
 of steel is quite uncertain, ofttimes varying from I/4 inch per foot to 
 ys inch. However, the usual allowance is 3-16 inch per foot for 
 ordinary work. ■* 
 
SHRINKAGE 
 
 11-VI 
 
 The common allowance made for the shrinkage of castings made 
 of different metals is as follows : 
 
 Cast Iron 3*, 
 
 Steel J*: 
 
 Brass T6 
 
 Yellow Brass 3^2 
 
 Bronze t^ 
 
 inch per foot 
 
 A method of graduating a shrink rule by hand — with the aid of 
 a standard scale — is illustrated in Fig. 12, and when this is carefully 
 done it will give entire satisfaction. Secure a standard rule to a board 
 in such a manner that the upper surface will be clear. Erect the 
 perpendicular line B C at one end. Now lay off the amount of shrink- 
 age as indicated at D. With A as the center and with a radius equiv- 
 alent to the length of the standard rule plus the amount of shrinkage 
 
 Fig. 12. Making a Shrink Rule 
 
 D, scribe an arc of a circle E F. Note the point of intersection with 
 the perpendicular line B C which is shown at G. A strip of suitable 
 material and of the same thickness as the standard rule is then secured 
 to the board in the position shown, its inner edge passing through 
 the point of intersection at G. The guide H can be made of steel 
 plate or wood with the strip I attached to bear against the outer edge 
 of the blank. If the guide is made of wood a piece of tin or steel 
 may be inserted at J to give the marking instrvunent a positive bearing. 
 The marking instrument should be thin and sharp. 
 
12- VI 
 
 SUGGESTIONS AND RIGS 
 CHAPTER VI 
 
 SOME HANDY DEVICES 
 
 Box Square 
 
 The accompanying illustration, Fig. 13, shows what is usuall> 
 termed a vertical plumb or box square. It is a handy device, which 
 will be found very convenient in transferring lines to irregular sur- 
 faces which do not lend themselves readily to the use of a square or 
 
 Fig. 1,?. Box Square 
 
 even a flexible rule. The device consists of a box square made of 
 wood and shown in Fig. 13. The marker consists of a straight piece 
 of hard wood shown in the upper part of Mg. 13,' and in dotted outline 
 at the riofht-hand side. 
 
 Fig. 14. Bo.x Square in Use 
 
 This marker has a brad driven into the end and filed to a point, 
 as shown at A. Sometimes the point is formed by a metal plate let 
 into the face of the marker at the point A. Care should be taken to 
 see that the scribing edge is in exact line with the face B. The man- 
 ner of using this device for drawing a line across a core box is shown 
 
A CORE BOX PLANE 
 
 13- vr 
 
 in Fig. 14. This can be used for drawing lines at right angles to a 
 center Hne of the box, or at any other angle, as in the case of core 
 boxes for pipe angles such as Y's, etc. This form of square is very- 
 useful in drawing lines across carved work, as in stove plate patterns. 
 Fig. 15 shows the application of a little different form of the box 
 square for external work. The square shown in Fig. 13 cannot readily 
 
 Fig-. 15. External Box Square 
 
 be adapted for this class of work on account of the webs C, which are 
 used to hold the pieces D and E in place. The form shown in Fig. 15 
 receives the necessary stiffening by the pieces A and B which are 
 attached to the end of the square proper, which is composed of pieces 
 C and D. 
 
 A Core Box Plane 
 
 In the accompanying figures I show a method of making a rabbet 
 plane serve as a core box plane. In the lower part of Fig. 16 side and 
 end views of the plane are shown, and it will be noticed that a block of 
 
 X^ 
 
 <5 ^-s.^' S 
 
 Fig. 16. Core Box Plane 
 
 hard wood has been screwed to the body of the plane at right angles 
 to it, the face of the block being allowed to project slightly beyond the 
 sole of the plane, so that it will come opposite the cutting edge of the 
 bit. The edge of the block should be gouged out slightly opposite the 
 throat of the plane to allow shavings to clear themselves freely. In 
 the upper part of the figure the plane is shown in use. 
 
14-VI 
 
 SUGGESTIONS AND RIGS 
 
 Wooden Calipers 
 
 For calipering large work it is frequently difficult to obtain a pair 
 of calipers large enough which will at the same time be delicate enough. 
 Large metal calipers are very heavy and hence not as delicate as might 
 be desired. Fig. 17 shows a light wooden frame caliper made up of 
 
 Fig. 17. Large Wooden Calipers 
 
 strips of hard wood screwed together and provided with adjustable 
 pins made from ordinary dowel pin stock. This device will be found 
 very handy indeed for turning large parallel work. 
 
CROOKED CORE BOXES 
 CHAPTER VII 
 
 15 -VI 
 
 SOME HANDY KINKS 
 
 Elbow Core Boxes 
 
 All patternmakers have had to construct core boxes for elbow- 
 patterns, and in many cases the pattern is wanted yesterday. This 
 means a decidedly hurry-up job. Fig. 18 illustrates one method of 
 performing such a hurry-up job. This shows the outline of the elbow 
 
 FIG. 18 
 
 FIG. 19 
 
 FIG. 20 
 
 FIG. 21 
 
 Fig. 18. Elbow Core Box Fig. 19. Wedges Tacked Together 
 
 Fig. 20. Joints Parallel to Parting Fig. 21. Joints Perpendicular to Parting 
 
 core box and also shows the method of construction. The bend, it 
 will be noticed, is formed by a series of wedge-shaped pieces — six in 
 all — these pieces being fitted in place, laid out, numbered, taken apart 
 and then tacked together in pairs, as shown in Fig. 19. They are then 
 
16- VI 
 
 SUGGESTIOXS AXD RIGS 
 
 band-sawed, taken apart and replaced. The rest — that is, the finishing- 
 — is a very easy job. particularly if the ends, A and B, have been band- 
 sawed to line. The job can be made still easier by the use of the 
 7^ degree wedge, shown at the left of Fig. 2. This can be used 
 in each of the separate blocks, in place of tacking them together in 
 pairs. 
 
 It will be noticed that the angle of the sides of the wedge block 
 is only one-half that of the other wedges. By using this device, the 
 
 Figr. 22, Screws in End Grain 
 
 stock to be trimmed ofif by hand after sawing will be reduced to a 
 minimum. 
 
 The old-time way of turning the bend and throwing away one-half 
 or three-quarters is much slower than the one here shown. 
 
 Stock for Cylindrical Patterns 
 
 In gluing up stock for cylindrical shaped patterns, it is customary 
 to have the joints parallel with the parting, as shown in Fig. 21. 
 This is certainly not good practice in many cases, as the parting does 
 not remain straight across the grain, while the job is being made. If 
 the glued joints are made at right angles to the parting, as shown in 
 Fig. 20, there will be very little, if any, trouble from open joints, and 
 the pattern will last much longer. 
 
 Screws in End Grain 
 
 When mserting screws into end grain, especially in the case of 
 pine, they do not take a very firm hold, especially when the screws 
 
SCREWS IX EXD GRAIN 17-VI 
 
 h-^vc to be removed frequently as in core boxes where the work re- 
 quires the separation of the parts. In such a case the thread formed 
 by the screw into the wood will soon become stripped off. A very 
 good manner of overcoming this trouble is shown in Fig. 22, in which 
 case holes are bored and hardwood plugs inserted, the screws being 
 allowed to pass through the plugs at right-angles to the grain. When 
 the plugs become badly worn from the repeated removal and reinser- 
 tion of the screws, they may be knocked out and new plugs inserted. 
 
18-VI SUGGESTIONS AXD RIGS 
 
 CHAPTER VIII 
 WARPING OF CASTINGS 
 
 The warping of castings, owing to variations in the thickness of 
 metal, is an obstacle quite often encountered by the patternmaker, and 
 one not always considered by him until his attention is called to a badly 
 warped casting and he is asked to explain its cause. The chances are 
 that too often he will say "Consult the foundry foreman, for he is to 
 blame. They probably lifted the cope off too soon." Or he will make 
 some similar statement. 
 
 A good illustration of this kind came under the writer's observa- 
 tion not long since, when a casting like that shown in Fig. 23 was to 
 be made. In this illustration the casting is shown by the full lines dis- 
 torted as it came from the mold, and the dotted lines show the outline of 
 the required casting. The distortion has been exaggerated for the sake 
 of making it plainer in the illustration. This was one of four sections 
 for a floor plate, as used in machine shops doing heavy work, and when 
 placed together the four pieces form a surface of 1,024 square feet, 
 each section being 32 feet long, 8 feet wide, and 16 inches in depth. 
 Each casting weighed 22 tons. In the flanges and lower part of the 
 casting the metal was \}i inches thick, while in the upper surface, 
 which contained the T slots for the bolt heads, it was about 4^ 
 inches thick. 
 
 On inspecting the first casting, it was found to be warped as 
 shown in Fig. 23. This warping amounted to F>^ inches in the length 
 of the casting. An attempt was made to straighten the casting by 
 heating, but it was finally rejected and broken up for scrap. 
 
 The cause of the casting warping to such an extent was then 
 discussed and the conclusion reached that, owing to the upper part 
 of the casting when molded being of a much lighter section, it cooled 
 first. Also the cores for this section tended to counteract shrinkage. 
 Later, when the heavy surface containing the slots for the bolts 
 cooled it shrunk and sprung the upper surface out of true as shown. 
 Of course the piece was molded with the heavy face down in order 
 to secure good metal for this finished surface. 
 
 To avoid this warping it was decided to rebuild the pattern which 
 was constructed as before, in length about 12 inches longer than 
 one-half of the required casting, only that the surface of the pattern 
 was made to conform with the warped surface of the first casting, 
 except that the pattern was warped in the reverse direction. This 
 pattern is shown in Fig. 24, the warp here also being exaggerated 
 
WARPING OF CASTIXGS 
 
 I9-VI 
 
 for the sake of clearness. When the castings from this pattern were 
 taken from the mold they were all that could be desired, as none of 
 the four varied more than 54 inch. 
 
 In making the mold a hole was dug for the total length of the 
 casting and a half pattern placed in one end of this hole with one end 
 blocked up to the required height. It was then rammed and tucked 
 up and the two sectional cover flasks A and B, Fig. 25, placed in posi- 
 tion and rammed up with the parting between them as shown. Wing 
 bars were bolted to the outside of the flasks to support this overhang- 
 ing sand. The parting was made at an angle so as to allow the flasks 
 to be lifted off and replaced separately. The ramming of this portion 
 of the pattern being completed, the flasks were lifted off and marks 
 
 Holt slot core prints— — ==;i^— — - — 
 
 ^'iff. 24 
 
 Parting 
 
 rJParting 
 B I A 
 
 Fig. 25 
 
 Fig. 23. Warped Casting. Fig. 24. Pattern for Bed Plate 
 Fig. 25. Mold for Bed Plate. Fig. 26. T Slot Core Print 
 
 made on the mold opposite the center of the pattern, the pattern 
 drawn, turned end for end, and placed in the opposite end of the hole, 
 care being taken to see that the center line of the pattern came opposite 
 the mark made on the side of the mold. 
 
 As the pattern was constructed 12 inches longer than one-half 
 of the casting, this insured a 24-inch bearing upon the portion of the 
 mold already completed, and thus assisted in lining up and setting the 
 pattern for the second half. After the pattern was in place and tucked 
 and rammed up, the flask B was returned to its place, and the flasks 
 C and D placed successively in position and rammed up, the partings 
 being made as shown. The flasks were then lifted off, the pattern 
 drawn, the mold finished, the cores set, gates cut, and all made ready 
 
20-Vl SUGGESTIONS AND RIGS 
 
 for pouring. In Fig. 25 the pattern is shown in its second position in 
 the mold. 
 
 In order to avoid the use of a large number of chaplets on top of 
 the cores for the T slots, a very simple device was resorted to. This 
 device has been described in the Section on ^Molding in Cores, but is 
 also shown in Fig. 26, as applied to this particular case. It will be 
 noticed that the core print is wider than the T slot, and hence when 
 a core of the cross section of the core print and T slot is placed in 
 the opening made by such a core print, and the metal flows into the 
 mold, there will be more area exposed in the width A than in the 
 width B, and hence the metal which exerts a lifting force under the 
 overhanging portions C will be more than balanced by the metal bear- 
 ing down on the portions D. When cores are made and carefully set 
 according to this system, no chaplets will be needed on top of them, 
 and of course after the entire core is submerged it will be held down 
 by the metal above it. The cores for forming the interior of the 
 casting between the ribs were made separately and set in place before 
 the mold was closed. 
 
 The interesting point in this matter is the fact that the pattern 
 had to be sprung a certain amoimt to overcome the spring which 
 would naturally result in cooling. The exact amount that any pattern 
 will have to be distorted to accomplish this result can only be ascer- 
 tained by experiment, though experience will enable a patternmaker 
 to make a very close approximation at the first trial. The depth of 
 cope used may in some cases have an influence on the results. 
 
DRAWING ARCS OF CIRCLES 21-VI 
 
 CHAPTER IX 
 
 ARCS OF CIRCLES 
 
 In patternmaking it is frequently necessary to draw arcs and 
 chords of large circles and in many cases it is not possible to do this 
 with trammels from the center. 
 
 An arc of a circle may be defined as any part of its circumference 
 and is measured along its circumference. 
 
 A chord is a straight line joining the extremities of an arc. 
 
 A segment of a circle is any part of a circle bounded by an arc 
 and its chord. 
 
 These various parts are plainly shown in Fig. 27. It often be- 
 comes necessary to lay off angles of a certain number of degrees and, 
 
 .__Are of Circle ___^ 
 
 ^ L 
 
 \ ^ 
 
 H Chord ^ -^ a Chord 
 
 Chord of Circle 
 
 \ 
 \ 
 \ 
 \ 
 \ 
 \ 
 \ 
 \ 
 \ 
 \ 
 \ 
 
 / 
 
 / 
 / 
 
 / 
 
 / 
 
 / 
 
 / 
 
 Figr. 27. .Arc and Chf)rd uf a Circle 
 
 in many cases, especially in large work, the protractor or bevel is not 
 accurate enough and in such cases the chord may be calculated for the 
 given number of degrees and the largest diameter that the work will 
 permit. This insures accuracy and usually saves time over trying to 
 do an accurate job with the bevel. To obtain a chord for any given 
 number of degrees and a given diameter, refer to any engineer's 
 Pocketbook and turn to the table of Natural Sines, take the sine of 
 ^ of the given number of degrees and multiply this by the diameter 
 on which it is to be laid off. 
 
 For example, if it is desired to lay off a chord of 30 degrees for 
 a 12-foot circle we would turn to the table and find the natural sine 
 of one-half of 30 degrees or 15 degrees. This is .25882, and multiply- 
 ing this decimal by 12 feet, the diameter, gives 3.10584 feet. Reducing 
 this to inches by multiplying by 12 and reducing to common fractions 
 we have Z7 17-64 inches, as the length of the desired chord. 
 
22- VI 
 
 SUGGESTIONS AND RIGS 
 
 The accompanying table of chords dividing the circle into from 
 3 to 100 equal parts will be found very useful and will facilitate the 
 laying out of segments, arms of wheels, etc. 
 
 TABLE OF CHORDS 
 
 N 
 
 S 
 
 N 
 
 S 
 
 N 
 
 S 
 
 N 
 
 S 
 
 N 
 
 S 
 
 N 
 
 S 
 
 3 
 
 .86603 
 
 20 
 
 .15643 
 
 37 
 
 .084804 
 
 53 
 
 .059240 
 
 69 
 
 .045515 
 
 85 
 
 .036953 
 
 4 
 
 .70711 
 
 21 
 
 .14904 
 
 38 
 
 .082580 
 
 54 
 
 .058145 
 
 70 
 
 .044865 
 
 86 
 
 .036522 
 
 .S 
 
 .58779 
 
 22 
 
 .14232 
 
 39 
 
 .080466 
 
 55 
 
 .057090 
 
 71 
 
 .044232 
 
 87 
 
 .036103 
 
 6 
 
 .50000 
 
 23 
 
 .13617 
 
 40 
 
 .078460 
 
 56 
 
 .056071 
 
 72 
 
 .043619 
 
 88 
 
 .035692 
 
 7 
 
 .43388 
 
 24 
 
 .13053 
 
 41 
 
 .076549 
 
 57 
 
 .055089 
 
 73 
 
 .043022 
 
 89 
 
 .035291 
 
 8 
 
 .38268 
 
 25 
 
 .12533 
 
 42 
 
 .074731 
 
 58 
 
 .054139 
 
 74 
 
 .042441 
 
 90 
 
 .034899 
 
 9 
 
 .34202 
 
 26 
 
 .12054 
 
 43 
 
 .072995 
 
 59 
 
 .053222 
 
 75 
 
 .041875 
 
 91 
 
 .034516 
 
 10 
 
 .30902 
 
 27 
 
 .11609 
 
 44 
 
 .071339 
 
 60 
 
 .052336 
 
 76 
 
 .041325 
 
 92 
 
 .034141 
 
 11 
 
 .28173 
 
 28 
 
 .11197 
 
 45 
 
 .069756 
 
 61 
 
 .051478 
 
 77 
 
 .040788 
 
 93 
 
 .033774 
 
 12 
 
 .25882 
 
 29 
 
 .10812 
 
 46 
 
 .068243 
 
 62 
 
 .050649 
 
 78 
 
 .040267 
 
 94 
 
 .033415 
 
 13 
 
 .23932 
 
 30 
 
 .10453 
 
 47 
 
 .066793 
 
 63 
 
 .049845 
 
 79 
 
 .039757 
 
 95 
 
 .033064 
 
 14 
 
 .22252 
 
 31 
 
 .10117 
 
 48 
 
 .065401 
 
 64 
 
 .049068 
 
 80 
 
 .039260 
 
 96 
 
 .032719 
 
 15 
 
 .20791 
 
 32 
 
 .098018 
 
 49 
 
 .064073 
 
 65 
 
 .048312 
 
 81 
 
 .038775 
 
 97 
 
 .032381 
 
 16 
 
 .19509 
 
 33 
 
 .095056 
 
 50 
 
 .062791 
 
 66 
 
 .047582 
 
 82 
 
 .038303 
 
 98 
 
 .032051 
 
 17 
 
 .18375 
 
 34 
 
 .092269 
 
 51 
 
 .061560 
 
 67 
 
 .046872 
 
 83 
 
 .037841 
 
 99 
 
 .031728 
 
 18 
 
 .17365 
 
 35 
 
 .089640 
 
 52 
 
 .060379 
 
 68 
 
 .046184 
 
 84 
 
 .037391 
 
 100 
 
 .031411 
 
 19 
 
 .16460 
 
 36 
 
 .087156 
 
 
 
 
 
 
 
 
 
 The quantities in the column headed S are the sines of half the 
 angles as already explained. The quantities in the columns headed 
 N are the number of equal parts into which it is desired to divide 
 a circle. For instance, if it is desired to divide the circumference 
 of a gear four feet in diameter for 23 teeth we would look in the 
 column N for 23, and opposite this, under S, we would find the decimal 
 .13617, multiplying this by 48 inches, or the diameter, will give us 
 6.536 inches as the distance to which our dividers should be set. 
 
 Fijj. 28. Graphic Method of Drawing an .^rc 
 
 The radius of a given piece of work is often so great that the 
 floor space available is not sufficient to lay out the work, or it would 
 be impossible to use a trammel beam of the desired length. In such a 
 case as this it becomes necessary to draw the arc of the circle without 
 the use of a center. The rise of the arc must first be obtained, and the 
 following calculation is one way in which this can be done. Square 
 
DRAWING ARCS OF CIRCLES 23-VI 
 
 the radius and from this subtract the square of one-half of the chord. 
 Extract the square root of the remainder and subtract the result from 
 the radius. This will give the rise. 
 
 A graphic method of drawing the arc is shown in Fig. 28. The 
 chord is first laid out and from the center the rise is drawn. From 
 the center of the chord scribe a quadrant of a circle with the rise as 
 a radius as shown. The quadrant should be divided into any conven- 
 ient number of equal parts. In the case illustrated, four have been 
 
 Fig. 29. Drawing Large Arcs 
 
 taken. Also the part of the chord A cut by the quadrant should be 
 divided into four equal parts and the points connected by the lines 
 C, D and E, as shown. Next, each half of the chord should be divided 
 into four equal parts, giving the points 1, 2 and 3. Through the 
 points 1, 2 and 3 draw lines parallel to C, D and E. From the points 
 at which the lines C, D and E intersect the quadrant, draw lines 
 parallel to the chord until they intersect the lines from the points 
 1, 2 and 3 in the points F, G and H, as shown. These will be points 
 on the circumference of the desired circle. Brads can be driven at 
 these points and a flexible strip bent along them to be used in drawing 
 the arc of the desired circle. 
 
 Another method of describing the arc of a circle without the 
 center is shown in Fig. 29. The rise of the arc having been obtained, 
 a suitable wooden triangle should be constructed as shown, making 
 A-B and C-D each longer than the chord of the arc. Lay off the 
 chord and rise on a board and at the extremities of the chord drive 
 brads and fasten the tracer point or pencil at the intersection of the 
 inner edges of the legs of the triangle and then move the triangle back 
 and forth, keeping the legs in contact with the brads. The tracer point 
 will then draw the arc required. 
 
2i-VI SUGGESTIONS AXD RIGS 
 
 CHAPTER X 
 CHORDS OF ANGLES 
 
 The accompanying table of chords of angles will be found very 
 useful in many operations in both the foundry and patternshop. It will 
 also tend to do away with much inaccuracy which is usually the result 
 of laying out angles which extend beyond the line of the protractor 
 blade. 
 
 To obtain the chord of any angle given in the table scribe an arc of 
 a circle with one of the radii given. With the trammel lay off the chord 
 of the required angle upon the circumference scribed. Now if lines 
 be drawn through the ends of the chord to the center of the circle 
 they will represent the angle desired. 
 
 Chords of intermediate angles not given in the table can be obtained 
 
 -3&Rdd * 
 
 Fig. 30. Diagram for Chords of Angles 
 
 by dividing the difference between two given angles, as shown in the 
 diagram. Fig. 30. 
 
 Example. — It is required to lay out an angle of 30° 30'. First: 
 Draw with a radius of 36 inches an arc BD. The base line AB is 
 drawn passing through the center of the circle, and by referring to the 
 table the chord of the angle of 30° upon the 31 inch radius is found 
 equal to 18 41-64 inches. With this length set off on the trammels 
 the chord BC is laid off. The chord of 31° is found to be equal to 19' 
 15-64 inches with a trammel set to this distance and B as the center, 
 the chord is drawn through D. Next, with the dividers set to any con- 
 venient radius the chord CD is bisected and the line drawn through the 
 points E and A will give the difference between the two angles, and 
 the angle BAE will equal to 30° 30'. 
 
CHORDS OF ANGLES 
 
 25-VI 
 
 91 
 p 
 
 CM 
 
 i, 
 
 o 
 
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 M W « 
 
 i 
 
 ■a 
 
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 00 
 
 -d 
 
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 COOOOO ONONJ^OvO O O O '1 'I " ►^ «N M M « rOrOrOrO-n-'^Tj-Tj-loiOU-, 
 
 
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 5 
 
 M <^ 'O'*- lOvO t^OO On O •- <N '^ -* >Ov£) t^OO CT< O i-i <N f^ tJ- lOvT r^OO Oi O 
 
 
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 00 0^ O tN fO •* ir>vD 00 CJN O ^ IN ro iOv£) t^OO CT» O M rO -^ "OvO t^OO OO O P< 
 
 
 
 
 00 
 
 -d 
 
 
 
 0^0^0 O O w m - M M CS CS rOrOrOrJ-rt'^'^lOlO lO^O vO vO vO t^ t^ r^CO 
 
 be 
 a 
 < 
 
 Q 
 
 I-" <N f) •* 'OvO t^oO ON O w W rOTt- lOVO t^OO 0^ O i-i M cO Tf iOnO r>.00 On O 
 
 0) 
 
 
 - M ro lOvO 1^00 O M M rO »OvO t^OO O m P< rO »Ovp t^oO CT\ « « rO '^VO r^ 
 
 CO 
 
 k 
 
 -d 
 •a 
 
 
 03 
 
 3 
 
 00 
 
 -d 
 
 to d^'^^cchoHooH^JH^'^^ FOMpo^i^ r^Nfte**to whoio'w^hHiM' — Hooh«5OT^i&'-d ""r-.^-.ti^ to*"!— 
 iO|^iel«,-»H „ M >H « N «S rOfOfO-^'Tf'^iO'O'O 10\0 »^ vO r^ t^ t^OO 00 00 ON O^ 
 
 a 
 < 
 
 
 ►H tN| PDTj-iOvO t^OO On O w M tO"<»-ir5VO t^OO 0> O '- C ro ■* »OVO r«.CC ON O 
 MMl-lMMMl-lMIHI-lM('fHr«(M(>4C4CN(Mn''. 
 
2o-VI SUGGESTIONS AND RIGS 
 
 CHAPTER XI 
 
 RIGHT-ANGLED TRIANGLES 
 
 A table of right-angled triangles, which will be found convenient 
 in laying out large pattern and plate work, is given below. 
 
 In erecting a perpendicular at a given point upon the base line 
 A B, Fig. 31, select from the table the triangle of the most suitable 
 proportions to suit the work. Say for illustration we select the fifth 
 from the top of the table. This is a right-angled triangle, the propor- 
 tions of which are 8, 15 and 17. 
 
 From the desired intersection C with the base line A B lay off 
 
 Fig. 31. Right-angled Triangle 
 
 the point D which would be equal to 15 feet. Now with the trammels 
 set to an 8-foot radius, and C as the center, scribe the arc of circle E. 
 With D as the center and the trammels set to a 17-foot radius scribe 
 the arc of a circle F giving the point of intersection G and we have the 
 perpendicular line C G accordingly. 
 
 ■5 
 
 c ^ 
 
 Pi 
 
 1) 
 
 a 
 
 m 
 
 11- 
 
 X 
 
 -5 
 
 
 X 
 
 3 
 
 4 
 
 5 
 
 15 
 
 20 
 
 25 
 
 5 
 
 12 
 
 13 
 
 15 
 
 36 
 
 39 
 
 6 
 
 8 
 
 10 
 
 15 
 
 112 
 
 113 
 
 7 
 
 24 
 
 25 
 
 16 
 
 30 
 
 34 
 
 8 
 
 15 
 
 17 
 
 16 
 
 63 
 
 65 
 
 9 
 
 12 
 
 15 
 
 17 
 
 144 
 
 145 
 
 9 
 
 40 
 
 41 
 
 18 
 
 24 
 
 30 
 
 10 
 
 24 
 
 26 
 
 18 
 
 80 
 
 82 
 
 11 
 
 60 
 
 61 
 
 19 
 
 180 
 
 181 
 
 12 
 
 16 
 
 20 
 
 20 
 
 21 
 
 29 
 
 12 
 
 35 
 
 37 
 
 20 
 
 48 
 
 52 
 
 13 
 
 84 
 
 85 
 
 20 
 
 99 
 
 10] 
 
 14 
 
 48 
 
 50 
 
 
 
 
POLYGONS 27-VI 
 
 CHAPTER XII 
 
 A TABLE OF POLYGONS 
 
 This table of polygons will be found very useful in shop practice. 
 It has been arranged in this handy form so as to save as much calcula- 
 tion as possible. 
 
 The diagram, Fig. 2)2, shows quite clearly what is meant by the 
 words "diameter" and "sides." The formulas may be explained — if 
 additional explanation is found necessary — by the following : 
 
 A TABLE OF POLYGONS 
 
 No. of 
 Sides 
 
 Coef. 
 
 No. of 
 Sides 
 
 Coef. 
 
 No. of 
 Sides 
 
 Coef. 
 
 No. of 
 Sides 
 
 Coef. 
 
 No. of 
 Sides 
 
 Coef. 
 
 No. of 
 Sides 
 
 128 
 
 Coef. 
 
 3 
 
 1.16 
 
 28 
 
 8.93 
 
 53 
 
 16.88 
 
 78 
 
 24.83 
 
 103 
 
 32.79 
 
 40.75 
 
 4 
 
 1.41 
 
 29 
 
 9.25 
 
 54 
 
 17.20 
 
 79 
 
 25.15 
 
 104 
 
 33.11 
 
 129 
 
 41.07 
 
 5 
 
 1.70 
 
 30 
 
 9.57 
 
 55 
 
 17.52 
 
 80 
 
 25.47 
 
 105 
 
 33.43 
 
 130 
 
 41 38 
 
 6 
 
 2. 
 
 31 
 
 9.88 
 
 56 
 
 17.83 
 
 81 
 
 25. 79 
 
 106 
 
 33.74 
 
 131 
 
 41.70 
 
 7 
 
 2.31 
 
 32 
 
 10.20 
 
 57 
 
 18.15 
 
 82 
 
 26.11 
 
 107 
 
 34.06 
 
 132 
 
 42.02 
 
 8 
 
 2.61 
 
 33 
 
 10.52 
 
 58 
 
 18.47 
 
 83 
 
 26.43 
 
 108 
 
 34.38 
 
 133 
 
 42.34 
 
 9 
 
 2.93 
 
 34 
 
 10.84 
 
 59 
 
 18.79 
 
 84 
 
 26.74 
 
 109 
 
 34.70 
 
 134 
 
 42.66 
 
 10 
 
 3.24 
 
 35 
 
 11.16 
 
 60 
 
 19.11 
 
 85 
 
 27.06 
 
 110 
 
 35.02 
 
 135 
 
 42.98 
 
 11 
 
 3.55 
 
 36 
 
 11.47 
 
 61 
 
 19.42 
 
 86 
 
 27.38 
 
 111 
 
 35.34 
 
 136 
 
 43 29 
 
 12 
 
 3.86 
 
 37 
 
 11.79 
 
 62 
 
 19.74 
 
 87 
 
 27.70 
 
 112 
 
 35.65 
 
 137 
 
 43.61 
 
 13 
 
 4.18 
 
 38 
 
 12.11 
 
 63 
 
 20 06 
 
 88 
 
 28 02 
 
 113 
 
 35.97 
 
 138 
 
 43.93 
 
 14 
 
 4.49 
 
 39 
 
 12.43 
 
 64 
 
 20.38 
 
 89 
 
 28.33 
 
 114 
 
 36.29 
 
 139 
 
 44.25 
 
 15 
 
 4.81 
 
 40 
 
 12.74 
 
 65 
 
 20.70 
 
 90 
 
 28.65 
 
 115 
 
 36.61 
 
 140 
 
 44.57 
 
 16 
 
 5.12 
 
 41 
 
 13.06 
 
 66 
 
 21.02 
 
 91 
 
 28 97 
 
 116 
 
 36.93 
 
 141 
 
 44.88 
 
 17 
 
 5.44 
 
 42 
 
 13.38 
 
 67 
 
 21.33 
 
 92 
 
 29.29 
 
 117 
 
 37.25 
 
 142 
 
 45.20 
 
 18 
 
 5 76 
 
 43 
 
 13.70 
 
 68 
 
 21.65 
 
 93 
 
 29.61 
 
 118 
 
 37.56 
 
 143 
 
 45 52 
 
 19 
 
 6.07 
 
 44 
 
 14.02 
 
 69 
 
 21.97 
 
 94 
 
 29.93 
 
 119 
 
 37.88 
 
 144 
 
 45.84 
 
 20 
 
 6.39 
 
 45 
 
 14.33 
 
 70 
 
 22.29 
 
 95 
 
 30 24 
 
 120 
 
 38 20 
 
 145 
 
 46.16 
 
 21 
 
 6.71 
 
 46 
 
 14.65 
 
 71 
 
 22.61 
 
 96 
 
 30.56 
 
 121 
 
 38.52 
 
 146 
 
 46.48 
 
 22 
 
 7.03 
 
 47 
 
 14.97 
 
 72 
 
 22.92 
 
 97 
 
 30.88 
 
 122 
 
 38.84 
 
 147 
 
 46.79 
 
 23 
 
 7.34 
 
 48 
 
 15.29 
 
 73 
 
 23.24 
 
 98 
 
 31.20 
 
 123 
 
 39.16 
 
 148 
 
 47.11 
 
 24 
 
 7.66 
 
 49 
 
 15.61 
 
 74 
 
 23.56 
 
 99 
 
 31.52 
 
 124 
 
 39.47 
 
 149 
 
 47.43 
 
 25 
 
 7.98 
 
 50 
 
 15.93 
 
 75 
 
 23.88 
 
 100 
 
 31.84 
 
 125 
 
 39.79 
 
 150 
 
 47.75 
 
 26 
 
 8.30 
 
 51 
 
 16.24 
 
 76 
 
 24.20 
 
 101 
 
 32.15 
 
 126 
 
 40.11 
 
 151 
 
 48.07 
 
 27 
 
 8.61 
 
 52 
 
 16.56 
 
 77 
 
 24.52 
 
 102 
 
 32.47 
 
 127 
 
 40.43 
 
 152 
 
 48.39 
 
 To obtain the length of a side : Divide the diameter of the circle 
 by the coefficient. 
 
 To obtain the diameter : The length of the side is multiplied by 
 the coefficient. 
 
 To obtain the coefficient : The diameter of the circle is divided by 
 the length of the side. 
 
 This table will be found convenient in obtaining the chords of 
 segments and similar work. 
 
28-VI 
 
 SUGGESTIOXS AND RIGS 
 
 Coefficient = 
 
 Dia m. 
 Coef. 
 
 Dlam. = Coef. x Side 
 
 Fig. 32. Polygon Diagram 
 
BEGINNING A PATTERN 29- VI 
 
 CHAPTER XIII 
 
 GENERAL SUGGESTIONS 
 
 Under the above heading the writer has arranged a number of 
 remarks and suggestions pertaining to patternmaking, which, if given 
 careful consideration and combined with a fairly good streak of self- 
 confidence, will go a long way toward the make-up of a thorough and 
 proficient workman. To become a good patternmaker one must become 
 to some extent an engineer. He must be somewhat informed upon the 
 principles of machine design and the construction of various kinds of 
 machinery, and he must have a thorough knowledge of molding and 
 also a knowledge of drawing. By the latter I do not mean merely the 
 making of drawings or layouts which are copies of the drawings fur- 
 nished by the designer or draftsman, but an understanding of the prin- 
 ciples of projection as applied to geometrical figures. 
 
 He must be able to read any mechanical drawing readily and form 
 a clear idea of what the draftsman intended to convey by the drawing 
 and he must also comprehend all of the details to the minutest degree. 
 
 To become an expert in the handling of tools, which is one of the 
 necessary requirements of the trade, it is only acquired by constant 
 practice for a long time, and this practice is usually accompanied by 
 scarred fingers. 
 
 What to Observe When Beginning Work Upon a Pattern 
 
 Upon receiving a drawing for a pattern to be made, note the 
 metal to be used for the casting and the number of castings to be made. 
 The number of castings to be made will determine whether a tempor- 
 ary, medium or standard pattern is required and will also determine 
 the method of construction. The construction of the pattern should be 
 governed in such a way as to produce a casting with the smallest 
 expenditure of time, labor and material, in both the pattern shop and 
 the foundry. In many cases extra time spent in the pattern shop in 
 making a better pattern will be more than saved in the foundry, or vice 
 versa. Next, check all of the intermediate or minor dimensions to see 
 whether they agree with the over-all dimensions. This will often save 
 trouble later on as an error is corrected more easily on paper than in 
 v.'ood or metal. 
 
 If detailed drawings of a machine or other device to be constructed 
 are received they should be accompanied by a general drawing and this 
 should be looked over and the general arrangements and dimensions 
 checked. 
 
30-VI SUGGESTIOXS AXD RIGS 
 
 Temporary patterns are those not likely to be used more than 
 once. They should be made with as little expenditure of labor and ma- 
 terial as possible to produce the required casting. Unless there is 
 plenty of space in the pattern loft this grade of patterns should not 
 be preserved, but taken apart and the material used up, if possible. 
 
 Medium patterns are that class of patterns likely to be used 
 occasionally and hence more care should be taken in their construction 
 than in the case of the class already mentioned, as they are required 
 to withstand more hard usage in the foundry, as well as the distortion 
 likely to occur during the storage in the pattern loft. 
 
 Standard patterns are those which are frequently used or in con- 
 stant use and no pains should be spared in their construction, as they 
 cannot be made too substantial. 
 
 Economical Use of Lumber and Supplies 
 
 If dififerent grades of material are provided they should be used 
 with discretion. Knots and shaky material will not affect the inside 
 of a box or framed up pattern. When the pattern to be made is of 
 large size, special provision should be made for rapping and drawing 
 it. If the pattern is too large to handle and store conveniently, it 
 should be made in sections which are pinned and bolted together during 
 the construction of the pattern. 
 
 The Layout Board 
 
 This should only be used for such work or such sections of work 
 as absolutely require it. For instance, in the making of web patterns 
 or when there is a surface which can be laid out and the material then 
 gotten out and laid down to this outline and worked to it. In such a 
 case one layout answers both for the determination of the dimensions 
 and for the fitting of the stock. 
 
 Center Lines 
 
 I wish to place proper stress upon this point in patternmaking, 
 as it is one that is often overlooked. Prominent center lines should 
 be scribed on all sides of the pattern and across the joint. If this is 
 carefully observed the chances of error will be greatly reduced and the 
 checking of the pattern facilitated. It will also improve the disposition 
 of the pattern checker. 
 
 Contraction 
 
 The contraction or shrinkage should be carefully considered. The 
 shrinkage of castings is to a large extent governed by their form and 
 the met^l distribution. The presence of dry sand cores in the mold has 
 
SHRINKAGE 31-VI 
 
 a tendency to retard or resist the shrinkage. Hard iron or steel will 
 shrink more than soft iron. Yellow brass will shrink more than bronze, 
 etc. Castings of a cylindrical or box section will shrink more in length 
 than in diameter, that is, more along the core than across it, the 
 shrinkage in the diametrical direction or at right angles to the core 
 being retarded or resisted by the dry sand core. It is good practice 
 in cases of this kind to allow one-half of the standard shrinkage for 
 the diameter of the cylinder or across the box section. 
 
 Shrinkage for Cast Iron 
 
 The conventional allowance for the shrinkage of cast iron is 
 3-32 of an inch per foot for ordinary work. When castings assume 
 large proportions, such as heavy engines or generator frames and 
 large cylinders, the shrinkage is reduced, owing to the swelling of 
 the mold, on account of the great pressure of the iron. Patterns for 
 large cylinders are usually made with a 1-12-inch allowance per foot 
 for shrinkage, while heavy engines or generator frames receive but 
 1-16 of an inch per foot. Heavy hammer blocks and counter weights 
 are usually made with a standard rule, in other words, with no allow- 
 ance for shrinkage. 
 
 Shrinkage of Steel Castings 
 
 The shrinkage of steel castings is not to be relied upon as a con- 
 stant. The usual allowance is 3-16 of an inch per foot, but it is subject 
 to frightful variations. Plain straight castings will often shrink from 
 54 to 5-16 of an inch per foot, while in dry sand cored molds they 
 will not shrink more than ^ of an inch per foot. When, however, 
 a contraction of only ^ inch is allowed, a liberal allowance should be 
 made for finish upon all surfaces to be machined to insure the proper 
 dimensions should the shrinkage of the castings exceed the contraction 
 allowed. In many cases the shrinkage appears to be an ungovernable 
 element and is apt to vary either way. As a consequence, what is 
 usually termed "playing safe" is generally resorted to, that is, the back 
 of the outer flange is thickened up to counteract or overcome the bad 
 results which would result if the shrinkage should exceed that allowed, 
 for in the latter case the flanges would finish up too thin. It is 
 better in most cases to have the flanges a trifle over thickness than 
 below thickness. It will also be found well to make the outlaying 
 pads a little wider than the drawing calls for. 
 
 Tie pieces or tie bars are placed upon the castings to prevent 
 the spreading of certain parts in cooling, or to assist the shrinkage 
 when such parts are separated by dry sand cores. These tie bars are 
 
32-VI SUGGESTIONS AND RIGS 
 
 more applicable to and, in fact, are an essential feature in the production 
 of good steel castings, as in the latter class of castings shrinkage 
 plays such an important part. 
 
 The introduction of these bars is really a point in molding that 
 should be taken care of by the foundryman who is supposed to make 
 such provisions as are necessary to produce a casting true to pattern, 
 but provision for these pieces should be made in the core box or upon 
 the pattern. If these precautions are not taken and the casting is 
 delivered to the machine shop badly out of shape, the pattern shop 
 will no doubt hear about the amount of finish it allowed. 
 
 Amount of Finish 
 
 The finish to allow is oftentimes a troublesome problem for the 
 patternmaker. The amount that will satisfy one machinist will not 
 satisfy another. The proper amount of finish depends to a great extent 
 upon the size of the piece to be machined, the method of casting, and 
 whether or not it is turned out like the pattern. It is advisable to 
 make this allowance as small as possible, but at the same time to 
 leave sufficient material for the proper finishing of the casting. As 
 a rule, iron castings which are produced in loam molds and castings 
 made from steel are apt to vary from the proper dimensions more than 
 those molded by other methods. 
 
 Steel castings or loam molded iron castings should receive an 
 allowance of from }i to y^ inch for finish and this should be sufficient 
 for ordinary sized work. F"or the general run of green sand cast- 
 ings from 3^ to 34 inch should be an ample allowance. For small brass 
 and machine molded iron castings which are of sound metal 1-16 of 
 an inch should answer. 
 
 Tool Clearance 
 
 The patternmaker should consider the method in which the casting 
 is to be finished or machined and then see that the proper tool clear- 
 ance is allowed wherever it is required, as for instance, at the ends of 
 all surfaces to be planed or milled. A little thought expended on this 
 point will save many hours of chipping in the machine shop. Some 
 unscrupulous fellow will say, "Oh, that's none of my business. They 
 should look after the machining of the castings." This is not the 
 proper spirit for the patternmaker to exhibit, as he should have an 
 interest in the casting clear through to the final erection of the machine. 
 
 Construction of Patterns and Core Boxes 
 
 Having discussed some of the allowance and provisions for the 
 molding and machining of castings, let us proceed with the pattern 
 
CORE PRINTS 33-VI 
 
 and core box work, taking up a number of points which will facilitate 
 this work and economize material. These points will also serve to 
 save time in the foundry. 
 
 Machines are placed in the pattern shop to do the work and hence 
 the patternmaker should see that the machines do the work and thus 
 save his own strength and labor. 
 
 Glue is an indispensable material in pattern construction, but it 
 should be applied with judgment, as there is a time to use glue and a 
 time to let it alone. Many a badly warped pattern can be traced to 
 the manner of gluing up the stock. Cross gluing should be avoided 
 wherever possible, for if any shrinkage or swelling takes place in such 
 a case a distorted or twisted pattern will surely result. Unnecessary 
 gluing often causes no end of trouble and expense when an alteration 
 or change is to be made upon a pattern. Screws may appear more 
 expensive than a few nails or a few spots of glue, but it is not always 
 so, and their use should be encouraged. 
 
 Core Prints 
 
 This is one of the knotty problems for the patternmaker to solve, 
 but we will not attempt to settle it this time. The length or width of 
 a core print that will answer one molder to a nicety will not suit another 
 at all. The writer, however, believes in a good liberal allowance for 
 all core prints, despite the fact that patterns often come back from the 
 foundry with a portion of the core print missing, it having been sawed 
 off by the foundry carpenter so that the pattern could be used in a 
 certain flask. Of course the length of any core print should be gov- 
 erned by the size or the diameter of the core to be set. When con- 
 structing core prints of irregular form, care should be taken and 
 provision made so that their outline can be readily transferred to a 
 core box, that is, such core prints should be built upon certain properly 
 determined lines and these lines noted on the layout. This method 
 of working will avoid the use of templets and other troublesome devices 
 which are often employed when such precautions are not taken. A 
 core print and core should be so marked and so constructed that there 
 is no chance of placing it in the mold in any position except that in 
 which it is intended to go. This point is often overlooked by the 
 patternmaker and rarely detected by the molder unless the difference 
 is quite noticeable. 
 
 Loose Pieces 
 
 Loose pieces on patterns, although objectionable, cannot always 
 be avoided and in many cases would be found more economical and 
 
3i-VI SUGGESTIONS AND RIGS 
 
 less objectionable than a core. When it becomes necessary to choose 
 between the two methods of using a loose piece or a core it will gen- 
 erally be found better to use the former, because it will insure a truer 
 casting and avoid the scare caused by the introduction of a dry 
 sand core. 
 
 If loose pieces or core prints are attached by two dowel pins of 
 different diameters, the error, often caused by the molders or core- 
 makers attaching pieces in the wrong position, will be avoided. All 
 loose pieces or core prints should be marked or numbered plainly so 
 that their respective positions can be determined at a glance. It is 
 also good practice to scribe a good, heavy line around them. This only 
 takes a moment, but it will often save the molder or co remake r many 
 a minute's search for the location of a detached loose piece. 
 
 The length and diameter of the core should also be marked upon 
 the core print when standard sizes are used, as the molder rarely has 
 a pair of calipers always at hand, as is the case with the patternmaker. 
 
 In the case of circular work when cores are used around the 
 interior or outer diameter of a large pattern the patternmaker should 
 mark the number of cores required to complete the circle upon the 
 pattern and upon the core box. This will show the coremaker instantly 
 the required number of cores to be made and save him the time and 
 trouble of stepping the distance off around the pattern. When a special 
 core is to be used and the core print does not distinguish it from the 
 regular standard foundry core the core print should be marked "special 
 core." This will often save the necessity of replacing the casting. 
 
 When making gear patterns it is well to get out several extra 
 teeth, bore a small hole through them and attach them to the pattern. 
 This will often save the pattern from mutilation by having several 
 teeth ripped off by the molder should the pattern fail to draw properly. 
 
 Another method of saving the pattern from abuse is to get out 
 a block five by three inches by two inches thick, with one side cut to 
 conform to the inner diameter of the rim of a gear pattern. The 
 molder is supposed to place this block against the inside of the rim 
 and then rap upon it with a hammer. Of course this rapping is done 
 after the cope has been lifted off. By this device the pattern can be 
 well rapped without injuring it. 
 
 In looking up gears in the pattern loft it will often be found con- 
 venient to have the patterns marked on each side of the rim with the 
 pitch diameter, circular pitch, width of face and number of teeth. 
 
 Old Patterns 
 These should always be treated with suspicion, as they are not to 
 
CORE BOXES 35-VI 
 
 be trusted, and have proven the pitfall of many a good workman. 
 Previous alterations are not always noted on the drawing and distor- 
 tions are very apt to occur during storage. For these reasns an old 
 pattern should be checked over thoroughly when making new additions. 
 Alter old patterns cheerfully, for though it is not a clean and agreeable 
 job. some of us must do it. so do it graciously, but we will not blame 
 you for kicking if you get more than your share. 
 
 Core Boxes 
 
 Whenever the circumstances permit core boxes should be con- 
 structed of rectangular form and filled in with the necessary material 
 to produce the required form of core. This manner of construction 
 of core boxes will be found advantageous and convenient in many 
 respects, and it will also save material, for when a good rigid frame 
 is constructed to begin with it can be filled in with material almost of 
 a temporary character, for such material cannot get out of place when 
 supported by the frame. This construction also saves the box from the 
 punishment it receives by rapping, for all that is required when the box 
 has been rammed up is to remove the screws from the opposite corners 
 of the frame and draw the frame away. The handling and the clamp- 
 ing of the box to the core plate is also facilitated by its rectangular 
 form. The material which forms the core box proper should be fitted 
 loosely in the frame, as it will have a tendency to swell and tighten 
 itself up. 
 
 Keep the length and width of your core box scant, as the core 
 would be liable to swell. 
 
 Bottom boards for core boxes should be made only when the form 
 of the core requires it. The construction of bottom boards is usually 
 only a waste of time and material and they are often thrown aside by 
 the coremaker, for they cause b.im an unnecessary roll over if used, 
 where by the use of the core plate the core is rammed up on the plate, 
 plate, the box removed and the cores sent direct to the oven. 
 
 • These suggestions are only a drop in the bucket in comparison 
 to the number of little big things that serve to make up successful 
 patternmaking and that present themselves day after day to every 
 workman. 
 
 By all means think for yourselves, think twice before you do it. 
 and then do not do it until you know why you are doing it. 
 
 Don'ts 
 
 Don't start your job until you have it well in mind, or you may 
 strike a snag later on. 
 
36-VI SUGGESTIONS ASD RIGS 
 
 Don't proceed with the pattern without noting the metal of which 
 it is to be cast. 
 
 Don't fail to inquire whether the grade of pattern is temporary, 
 medium or standard. 
 
 Don't forget that the art of quick patternmaking lies in knowing 
 where to slight it — but 
 
 Don't form the habit of slighting everything. The man that can 
 work according to his job is a valuable man. 
 
 Don't trouble the "Boss" with fool questions. He has troubles 
 of his own, besides you may expose your ignorance — at the same time 
 
 Don't try to get along without really necessary information on 
 the job at hand, which the Boss may have neglected to give you. 
 
 Don't make unnecessary layouts of work above all. 
 
 Don't take time to lay out a job, then not use the layout ; ]:)roperly 
 used, it will save time on the job. 
 
 Don't fail to study economy both of material and time ; both cost 
 your employer money. 
 
 Don't miss checking up all dimensions on the drawing before pro- 
 ceeding with pattern. 
 
 Don't make a pattern without knowing how it is to be molded, 
 simply because the old man told you to. 
 
 Don't accept your first inspiration as to the molding and construc- 
 tion of a pattern ; try and think out another way. 
 
 Don't start a job you don't see through, expecting to get an 
 inspiration as you go along. This idea wears out the floor between 
 your bench and the old man's desk. 
 
 Don't construct large patterns without provision being made for 
 handling, shipping or storing. 
 
 Don't be stingy with your core prints. 
 
 Don't be afraid that well defined center lines will spoil the looks 
 of your job. They will look good to the checker, and to the lad who 
 may have to change the job later. 
 
 Don't fail to put center lines on your core boxes, as well as your 
 patterns. A pattern like "Bread that is cast on the waters is seen 
 again after many days," and it may be up to you to change it. 
 
 Don't pick out all the snaps for yourself, when you have help on 
 a job. However good you may be — 
 
 Don't forget there are others. 
 
 Don't despise the help of the apprentice on the job. He did not 
 come in simply to learn to varnish, so let him do things. If he falls 
 down, pick him up, and — 
 
THINGS TO REMEMBER 37-Vl 
 
 Don't forget you had troubles, and when you are a has been, he 
 may help you. 
 
 Don't think that you know it all ; there are other men that know 
 a little. 
 
 Don't do by hand that which the machine should do, but you 
 
 Don't have to wait your turn at the band-saw to cut off a tooth- 
 pick. 
 
 Don't fail to study your machines and how to gjt the most out 
 of them, but 
 
 Don't take liberties or long chances with the jointer, especially 
 when the knives are dull. 
 
 Don't take long chances on the lathe, remember the adage, "An 
 ounce of prevention is worth a pound of cure." 
 
 Don't waste time setting bevels for standard cuts that are arranged 
 for on the saw table or trimmer. A little mental calculation and the 
 indicator is better. 
 
 Don't think because you see a circle on the drawing that the work 
 fnust be done in the lathe ; other pieces fit on sometimes, and 
 
 Don't forget that a sharp band-saw is a good tool and sawing to 
 the line, not quite a lost art. 
 
 Don't use your material for a footstool before working it up. It's 
 hard on the machines. 
 
 Don't wait until the rip or band-saw is just sharpened, then saw 
 nails ; if it must be done, do it before. 
 
 Don't swear when your plane hits a nail. The chances are you 
 put it there yourself. 
 
 Don't sandpaper each piece as you put it on the pattern, then 
 plane it afterwards. It takes time to sharpen tools, and — 
 
 Don't forget you buy your own. 
 
 Don't round up the ribs and corners of a pattern until all pieces 
 have been assembled. 
 
 Don't throw too much work on the foundry, but occasionally a 
 little stopping off saves time, and — 
 
 Don't leave the making of the stop-off piece to the foundry car- 
 penter ; he may not see things as you do. 
 
 Don't glue two pieces of wood together that have just come out 
 of the ice box. It's too chilly on the glue. 
 
 Don't carry your tools in a collar-box and expect the steady pins 
 to furnish the ones you haven't got. 
 
 Don't borrow tools and forget to return them, and especially — 
 
 Don't borrow when the other man is not looking. 
 
38-VI SUGGESTIOXS AXD RIGS 
 
 Don't assume any pattern is correct ; treat them all with suspicion 
 until proven. 
 
 Don't proceed with the alteration of an old pattern, without first 
 carefully checking it up. 
 
 Don't proceed with another workman's job without checking his 
 measurements. 
 
 Don't use screws when nails will do the work as well ; nails go 
 quicker and are cheaper. 
 
 Don't forget that supplies and lumber cost money ; if the other 
 fellow is paying for it — so 
 
 Don't fail to practise economy, and 
 
 Don't lug in a 16-foot plank and cut 4 or 5 inch print out of 
 the middle ; it's easier to turn over the scrap pile. 
 
 Don't keep your bench so littered up that it takes 5 or 10 minutes 
 to find some small tool you just laid down. 
 
 Don't think (if you happen to be a relative of one or more of the 
 firm) that you are entitled to more privileges than any other man. 
 
 Don't try to do as little as you can for the most you can get, and — 
 
 Don't do any fooling during working hours ; you are paid for 
 working — not playing. 
 
 Don't fail to report promptly when your job is completed. 
 
 Don't stand around and look wise when waiting for a job. Get 
 busy with your oil-stone. There are always tools to be sharpened. 
 
 Don't fail to check up your pattern when complete. 
 
 Don't leave your mistakes for others to find ; find them yourself, 
 and if you do — 
 
 Don't let them go on a chance of its getting past the checker. 
 Be sure your sins will find you out, even if it does rope in the other lad. 
 
 Don't say "that is near enough." 
 
 Don't fail to number and place location marks on all loose pieces 
 of pattern and core boxes. 
 
 Don't forget to place a marker upon the core print, if the core can 
 be reversed. 
 
 Don't fail to nail the lead letters and numbers on the pattern ; 
 one nail in each letter is not enough to ensure their staying right 
 side up. 
 
 Don't number the core boxes upon the face of box ; sand in time 
 will wear it off. 
 
 Don't size up your job and guess at the amount of lumber ; keep 
 account of the boards as you cut them up. 
 
 Don't forget an easy way to figure lumber is multiply the length 
 
THINGS TO REMEMBER 39-VI 
 
 in feet by the width in inches, by the thickness in inches, and divide 
 by twelve— example : 9 ft. X 8 in. X 1>4 in. ^ 12 = 9 ft. 
 
 Don't forget to mark upon the side of core boxes which way lift- 
 ing hooks for the core are to be placed. 
 
 Don't forget to mark the length of standard cores upon pattern 
 when used. This saves the molder's time, as well as the coremaker's. 
 
 Don't waste time doing unnecessary work. 
 
 Don't spend time and money giving patterns a piano finish — they 
 are not used for ornaments. 
 
 Don't get into a rut of doing any certain work ; try and improve 
 upon your method, as well as lessen the time. 
 
 Don't think you know more than the boss, even if you do. 
 
 Don't expect the highest wages, unless you can produce the goods. 
 
 Don't make a practice of being late to work. 
 
 Don't do government work in the Company's time. 
 
 Don't keep one eye on the boss and another on your job ; it's 
 difficult to watch them both. 
 
 Don't take off your apron and look for a chance to wash ud before 
 quitting time. 
 
 Don't dig ditches in the grindstone. 
 
 Don't touch a broken band-saw until the machine has stopped 
 running. 
 
 Don't leave the jointer with a heavy cut on ; run the table up. 
 
 Don't make the final calipering of your work while the lathe is 
 running. 
 
 Don't use double-ended turning tools, they are dangerous. 
 
 Don't forget that a tooth plane bit makes an excellent turning 
 chisel for straight work. 
 
 Don't forget that dowel pins belong in the cope half of pattern. 
 
 Don't fail to secure your work well in the lathe either between 
 centers or on the face plate. 
 
 Don't stand directly in front of the rip-saw, when sawing; they 
 sometimes kick. 
 
 Don't provide bottom boards for core boxes unless necessary ; they 
 are often a waste of time and material. 
 
 Don't forget to make your core boxes scant in length and width, 
 as cores, when drying, usually sag and swell. 
 
 Don't fail to make the necessary provisions for rapping and draw- 
 ing the pattern. 
 
 Don't forget to allow ample material for finishing the casting. 
 
 Don't forget to consider how the casting is to be machined, and 
 provide necessary tool clearance. 
 
40-VI SUGGESTIONS AND RIGS 
 
 Don't forget to put in tie pieces when required, to keep castings 
 from spreading or cracking. 
 
 Don't fail to consult the molder; his suggestions may be helpful, 
 and we cannot do without him. 
 
 Don't forget that the molder will always try to blame the pattern- 
 maker for his own mistakes, if he possibly can, and — 
 
 Don't forget that the molder is in a position to show you your 
 shortsightedness, so 
 
 Don't fail to consider the convenience of the molder and coremaker 
 at all times. 
 
 Don't think that your own time spent in the foundry is wasted; 
 it may or may not be, it lies with yourself. 
 
 Don't be too important to do insignificant work. 
 
 Don't fail to have confidence in yourself, but 
 
 Don't think you are a patternmaker because you have been inside 
 a pattern shop. 
 
 Don't lose your head when anything goes wrong; other people 
 have made mistakes. 
 
THE ELLIPSE 
 
 CHAPTER XIV 
 
 STRIKING AN ELLIPSE 
 
 41-VI 
 
 Various and curious have been the devices contrived for striking 
 an ellipse, and the fact does not seem to be universally known that the 
 .true way is the simplest. Fig. ZZ shows how it can be done with the 
 ordinary steel square, or in fact most anything that is handy, having 
 two of its edges at right angles, and a thin stick, say about yi x yz inch, 
 a little longer than one-half the major diameter of the ellipse. 
 
 Take the pieces you wish to lay out the ellipse on, mark off the 
 center lines, also the major and minor diameters, transfer the lengths 
 of the semi-major and semi-minor diameters to the stick, driving in 
 
 Fig. 33. Striking an Ellipse with a Square 
 
 two fine brads at these points. Next, place the square on the center 
 lines, the intersecting outer edges at the center of the ellipse, drive in 
 three small brads as shown in b\, hi and bZ; which will secure the 
 square in position. Then placing the stick in position the two brads, 
 which project through the under side slightly less than the thickness 
 of the square bearing against the two outer edges, move carefully to 
 the right and the tracer will mark out one-quarter of an accurate 
 ellipse. The draughtsman can do the same thing on his drawing by 
 utilizing his set square or triangle and thumb tacks, two pins and a 
 sliver. 
 
 Fig. 34 illustrates the same principle, the application being slightly 
 different. Take a piece of wood, large enough to make one-quarter 
 
42-VI 
 
 SUGGESTIONS AND RIGS 
 
 of the ellipse, trim off one end square with one edge, placing the end 
 against the edge of another piece of the same thickness, that is straight 
 on one edge, brad them lightly to the table, taking a narrow strip and 
 driving through it two brads, as stated in Fig. 33, placing the tracer 
 at the end of the stick, draw to the right, allowing the brads to slide 
 
 Fig. 34. Device for Striking an Ellipse 
 
 closely on the inside edges of the two pieces of stick, and the result 
 is the same as Fig. 33, by simply reversing the pieces you can get the 
 other parts, or you can cut out the quarter and use it as a templet. It 
 is exactly the same as an ellipsograph and just as accurate; but how 
 often do you rub against a patternmaker with one in his kit? Some 
 are minus other things more essential than ellipsograph; but a few 
 brads and a stick are always at hand. 
 
 o4l 
 
 Fig. .i5. Turning an Elliptical Valve 
 
 Fig. 35 is an illustration of turning up in the lathe an elliptical 
 valve which will fit accurately in a circular pipe at an angle of say 45 
 degrees. Having the diameter of the pipe which is the minor diameter 
 of the ellipse, ascertain the major or long diameter by laying out the 
 
THE ELLIPSE 
 
 43-VI 
 
 angle ; cut out of a piece of stock the required thickness of the valve, 
 an approximate ellipse, leaving sufficient stock on the edges for turning 
 off ; then take two pieces large enough to take in the butterfly and tail 
 stock centers and of sufficient length and rigidity, fasten them securely 
 in the center of the piece for the pattern, at an angle of 45 degrees, cen- 
 ter the ends and proceed to turn. It is not as difficult as it looks (the 
 dotted lines in sketch showing the exact contour of the edge as the 
 piece revolves), and with a modern screw feed lathe, would be a cinch. 
 This is a very quick way and will insure a perfect fit in the pipe. 
 
 Fig. 36 is a fairly good approximate layout of an ellipse by the 
 
 Fig. 36. Approximate Ellipse 
 
 divider route, A B is the major and C D the minor axis of an ellipse. 
 Space off B E equal to the semi-minor axis CO, using AE as radius for 
 the arc at each end of the minor axis. Bisect EO at F and space off 
 EG equal to EF and use GB as radius for the arc at each end of the 
 major axis. This is a very good approximate method, very nearly ap- 
 proaching perfection when the dift'erence in length of each axis is not 
 great. 
 
44-VI SUGGESTIONS AND RIGS 
 
 CHAPTER XV 
 
 SAWING LAGS 
 
 Most patternmakers determine the angle at which to set the fence 
 on the circular saw when sawing lags by trial or by guess. This method 
 is certainly not satisfactory, especially when there is such a simple 
 solution available. In the first place, to get the best results the lags 
 should be made as narrow as is consistent with good work. After the 
 lags have been cut to width and the sides to the proper angle, it is 
 necessary to concave the inner surface. This is usually done by 
 passing the lag diagonally across the circular saw. It must be borne in 
 mind, however, that when cylinders are cut at angles other than 90 
 degrees the result is the outline of a true ellipse, and hence it is evident 
 that this method would only give an approximately true circle. 
 
 To determine the proper angle at which to set the fence on the 
 saw table, a circle representing the saw should be laid off as shown at 
 "A" Fig. 37. The depth of the cut should be laid off as shown at "B" 
 
 t-iO.37 
 
 and the chord "C C" drawn. With one end of the chord "E" as a 
 center and with a radius equal to the inside width of the lag an arc 
 of a circle should be drawn. A tangent as shown at "D D" should 
 then be drawn touching this arc and passing through the other end 
 of the chord "C C." The bevel should then be set at the angfle 
 "D D C C," which will be the proper angle to use in setting the fence 
 on the saw table. 
 
 If the depth "B" is yi of an inch or less, as at "F," Fig. 38, the 
 surplus stock can be removed by a series of cuts over the saw ; but if 
 ■"B" is more than j4 of ^^ inch, most of the stock should be removed 
 
SAWING LAGS 
 
 45-VI 
 
 by making the two cuts through the center from the right and left, as 
 shown at "G," Fig. 38, thus cutting out a triangular-shaped piece and 
 preparing the work for finishing in the usual manner. 
 
 The best results are obtained by using a sharp saw with a good 
 spring set, and there is nothing to be gained by taking cuts so deep 
 that the stock is partially burned and torn out. It would be best if the 
 last cut does not exceed 1-64 of an inch in depth, providing the cut is 
 
 Fig. 38 
 
 narrower than the inside face of the lag ; for if it is attempted to cut 
 the entire face of the lag, the stock will shift as it is being passed over 
 the saw, settling down after the bearing of the rear portion has been 
 reduced and the front end of the sawed surface comes to a bearing 
 upon the table. 
 
 By carefully observing the rules given work can be finished in a 
 superior manner, and there is no better or quicker method of making 
 core boxes of large diameter and considerable length than by building 
 them up of lags upon half heads. 
 
INDEX 
 
 A 
 
 SEC. PACK 
 
 Arcs of circles \"I 21 
 
 B 
 
 Bearing, Core box for heavy engine 
 
 bed I 56 
 
 Ued plate, Casting of large \'I 19 
 
 Bevel gear patterns. Construction of.IX' 32 
 
 Bevel gears I\ 18 
 
 Bevel gears, Laying out teeth of...I\' 20 
 
 Box square, A \'I 12 
 
 c 
 
 Caliper, Large wooden \'I 14 
 
 Castings, Rig for producing cylin- 
 drical V 31 
 
 Castings, Warping of \'I 18 
 
 Cheeking off end of engine bed 
 
 pattern I 59 
 
 Cheeking off mold for havi'ser pipe. V 18 
 
 Chilian mill mortar pattern V 47 
 
 Chords of angles. Table of XI 25 
 
 Chords, Table of VI 22 
 
 Circles, Arcs of \'I 21 
 
 Cock, Molding a tliree-way II 14 
 
 Core bo.x and clamp combined \'I 6 
 
 Core box plane VI 13 
 
 Core boxes, Construction of VI 35 
 
 Core bo.xes for a double piston valve 
 
 cylinder I 35 
 
 Core boxes for a heavy engine bed. I 44 
 Core boxes for a low pressure 
 
 cylinder I 9 
 
 Core boxes for a jiiston valve 
 
 cylinder I 24 
 
 Core boxes for elbows VI 15 
 
 Core boxes for round flasks II 12 
 
 Core boxes for throttle valve V 5 
 
 Core boxes from pattern with plas- 
 ter paris, Making of II 3 
 
 Core for suction chamber, IMaking 
 
 of a Ill 9 
 
 Core prints VI 33 
 
 Core prints In sweep work. Use of. Ill 4 
 Cores for a slide valve cylinder. 
 
 Arrangement of I 4 
 
 Cores, Casting round flasks in II 11 
 
 Cores, Molding a three- way cock in. II 14 
 
 Cores, Molding in II 1 
 
 Cores, Molding in II 23 
 
 Cores, Molding large gear wheels in II 30 
 
 SEC. PAGE 
 
 Cores, Molding of a large steel 
 
 cutter head in II 26 
 
 Cores, Molding propeller wheel in. II 25 
 
 Cores, Molding of rope sheaves in. II 28 
 
 Cores T slot and name plate II 20 
 
 Cores for large work, Stacking of . . II 7 
 
 Cores, Use of covering II 17 
 
 Cores, Use of nail II 34 
 
 Coupling pins in cores, Molding of a 11 1 
 
 Cross templet work ^' 14 
 
 Cylinder pattern, A piston valve... I 16 
 Cylinder, I'attern for a double pis- 
 ton valve I 30 
 
 Cylinder, Pattern for low pressure.. I 7 
 
 Cylinder, Pattern for slide valve... I 1 
 
 Cylinder, Sweeping a plain Ill 1 
 
 Cylindrical castings, Rig for pro- 
 ducing ^' 31 
 
 D 
 
 Uelinitions relating to gearing IV 1 
 
 Don'ts yi 35 
 
 Drum mold. Sweeping a cylindrical 
 
 and conical Ill 24 
 
 Drum pattern. Cutting the score 
 
 in a VI 1 
 
 E 
 
 Elbow core box ^'I 15 
 
 Elbow, Making a crooked V 56 
 
 Ellipse, Striking an \'l 41 
 
 Engine bed, Pattern for a heavy... I 39 
 
 Engine patterns I 1 
 
 Epicycloidal odontograph I\' 9 
 
 Epicycloidal teeth IV 5 
 
 F 
 
 Finish, Amount of \'I 32 
 
 Flasks in cores. Casting round II 11 
 
 Forms in building skeleton patterns, 
 
 LTse of V 41 
 
 Furnace bell. Mold for a Ill 17 
 
 Furnace hopper, Mold for a Ill 17 
 
 G 
 
 Gear patterns. Construction of IV 15 
 
 Gear patterns. Construction of 
 
 bevel IV 32 
 
 Gear teeth, Involute IV 3 
 
 Gear teeth proportions. Involute. .. IV 11 
 
 Gear teeth to form, Sanding of.... IV 31 
 
INDEX 
 
 SEC. PAGE 
 
 Gear tooth jigs IV 13 
 
 Gear wheels in cores. Molding large II 30 
 
 Gears, Double helical IV 22 
 
 Gears, Laying out the teeth of 
 
 bevel IV 20 
 
 Gears, Worm IV 24 
 
 Gearing, Spur IV 1 
 
 Gluing stock for cylindrical pat- 
 terns VI 16 
 
 H 
 
 Hawser pipe patterns V 14 
 
 I 
 
 Involute gear teeth proportions. .. .IV 11 
 
 Involute odontograph table IV 7 
 
 Involute teeth IV 3 
 
 J 
 
 Joints for covering cores II 18 
 
 L 
 
 Lags, Sawing of \'I 44 
 
 Lathe tools ^'I 7 
 
 Loose pieces ^'I 33 
 
 Loose pieces in double piston valve 
 
 cylinder pattern, Use of I 32 
 
 Low pressure cylinder. Pattern for a I 7 
 
 M 
 
 Model in determining form of pat- 
 tern. Use of II 27 
 
 Mold for a double nozzle V 45 
 
 Mold for a furnace bell Ill 20 
 
 Mold for a furnace hopper Ill 21 
 
 Mold for a large steel nozzle or 
 
 saddle V 42 
 
 Mold for a low pressure cylinder.. I 11 
 
 Mold for a piston valve cylinder... I 28 
 
 Mold for a throttle valve V 4 
 
 "Mold for Chilian mill mortar V 55 
 
 Mold for cylindrical and conical 
 
 drum Ill 29 
 
 Mold for double piston valve cylin- 
 der I 36 
 
 Mold for hawser pipe V 18 
 
 Mold for nozzle pattern V 22 
 
 Molding a rope sheave in cores. . . II 28 
 
 Molding in cores II 23 
 
 Molding steel truck bolsters V 23 
 
 N 
 
 Nail cores. Use of II 34 
 
 Name plate cores II 20 
 
 Nozzle pattern, A V 20 
 
 
 
 Odontograph, Epicycloidal IV 9 
 
 Odontograph table for involute 
 
 teeth IV 7 
 
 Old patterns. Altering of VI 34 
 
 SEC. PAGE 
 
 p 
 
 Pattern, Use of a model for de- 
 termining form of II 2'^ 
 
 Pinion housing patterns \' 8 
 
 Pipe patterns, Hawser V 14 
 
 Piston valve cylinder pattern, A I 16 
 
 Plaster paris. Making core boxes 
 
 and patterns with II 3 
 
 Plug core prints. Use of N 20 
 
 Polygons, Table of VI 27 
 
 Propeller wheel in cores. Molding 
 
 of a II 25 
 
 Pulley ring for producing cylindrical 
 
 castings, Use of V 31 
 
 R 
 
 Reverse molding in plaster paris to 
 
 produce core boxes II 3 
 
 Right angle triangle VI 26 
 
 Rope sheave in cores. Molding of a II 28 
 
 s 
 
 Sawing lags VI 44 
 
 Score in a drum pattern. Cutting 
 
 of a VI 1 
 
 Screws in end grain VI 16 
 
 Seat in sweeping a core. Use of a. .Ill 9 
 Sectional patterns as applied to 
 
 Chilian Mill mortar V 51 
 
 Sheaves in cores. Molding rope II 28 
 
 Shrink rule. Making a \'I H 
 
 Shrinkage VI 10 
 
 Shrinkage of castings VI 31 
 
 Skeleton pattern for a double nozzle V 44 
 
 Skeleton patterns V 39 
 
 Slag ladle molds, Sweeping of Ill 12 
 
 Slide valve cylinder, Pattern for a. I 1 
 
 Spindle collar, A detachable Ill 13 
 
 Spindle collar, An ecceiitric HI 38 
 
 Spindle for variable pitch score... .Ill 25 
 
 ijpur gearing I\ 1 
 
 Square, A box ^ I 1- 
 
 Stacking of cores II 4 
 
 Steel castings in cores. Making 
 
 small II 1 
 
 Steel castings in cores. Making 
 
 large H 7 
 
 Steel castings in cores. Making 
 
 small II "' 
 
 Steel cutter head in cores. Molding 
 
 of II 26 
 
 Steel flasks in cores. Casting of... II H 
 
 Steel nozzle. Patterns for a V 20 
 
 Steel truck bolsters, Molding of a. V 23 
 
 Striking an ellipse VI 41 
 
 Suction chamber, Sweeping the 
 
 mold for a HI ' 
 
 Sweep work HI ^ 
 
 Sweeps, as applied to a low pressure 
 
 cylinder I ^ 
 
INDEX 
 
 SEC. PAGE 
 
 Sweeping a cylindrical and conical 
 
 drum Ill 24 
 
 Sweeping a plain cylinder Ill 1 
 
 Sweepnig a steel slag ladle mold.. Ill 12 
 
 Sweeping frame, A double Ill 36 
 
 Sweeping of core for cylinder.... I 37 
 Sweeping of mold for a suction 
 
 chamber Ill 7 
 
 Sweeping the mold for a furnace 
 
 hopper and bell Ill 17 
 
 Sweeping rig for variable pitch 
 
 score Ill 26 
 
 T 
 
 T slot cores II 20 
 
 Teeth, epicycloidal I\' 5 
 
 Teeth to bevel gears. Fitting of....I\' 19 
 
 Teeth for worm gears I\' 26 
 
 Teeth for bevel gears, Laying out of. IV 20 
 
 SEC. PAGt 
 
 Teeth, Sanding of gear I\' 31 
 
 Templet work. Cross \' 14 
 
 Thickness strips. Use of Ill 21 
 
 Three-way cock in cores. Molding 
 
 of a II 14 
 
 Throttle valve body pattern, .\.... \' 1 
 
 Tool clearance \"I 32 
 
 Tooth jigs for gears I\' 13 
 
 Triangle, Right angle \"I 26 
 
 Truck bolsters, Molding of steel... \' 23 
 
 Turning wooden balls \'I 9 
 
 V 
 
 N'alve, Pattern for a throttle \" 1 
 
 w 
 
 Warping of castings VI 1& 
 
 Wooden ball turning VI 9 
 
 Worm gears IV 24- 
 
MAY 6 1907