EGHKIGAL INSTRUCTION SERIES r H HP ES. Edited by P ^jjjjjjjlir lical Instruction THE LIBRARY House Decc G, PAINTING, etc. With 79 I OP Contents. ( VxJ. ,c. Tools used by ffibfi THE UNIVERSITY g. Whitewashing Embellishment of B ;'f pi OF CALIFORNIA FINISHING. With iocs. Re-Welting 2s?i<2 LOS ANGELES Stitching. Making How to Writ ;s and Diagrams. Contents. T ignwriter's Outfit. Making Signl Shaded and I >rms of Lettering, ng. Poster-Paint- ing. Letterin GIFT OF Wood Finish ings and . IG. With Engrav- Contents. ] d. French Polish- wlx FiniThin Stopping or B Off. Glazing and Reviving. Hard Varnishing Wood Varnishes. E Dynamos an ims. Contents. 1 ,nchester Dynamo. Simplex Dyn; Small Dynamos. Ailments of S s. Small Electro- motors withoi cation of a Motor. How to Make amo. Manchester Type 440-Watv -j Cycle Building and Repairing. With 142 Engravings and Diagrams. Contents. Introductory, and Tools Used. How to Build a Front Driver. Building a Rear-driving Safety. Building Tandem Safeties. Building Front-driver Tricycle. Build- ing a Hand Tricycle. Brazing. How to Make and Fit Gear Cases. Fittings and Accesso- ries. Wheel Making. Tires and Methods of Fixing them. Enamelling. Repairing. Decorative Signs of All Ages for All Purposes. With 277 Engravings and Diagrams. Contents. Savage Ornament. Egyptian Ornament. Assyrian Ornament. Greek Ornament. Roman Ornament. Early Christian Ornament. Arabic Ornament. Celtic and Scandinavian Ornaments. Mediaeval Ornament. Renascence and Modern Orna- ments. Chinese Ornament. Persian Ornament. Indian Ornament. Japanese Ornament. Mounting and Framing Pictures. With 240 Engravings, etc. Contents. Making Picture Frames. Notes on Art Frames. Picture Frame Cramps. Making Oxford Frames. Gilding Picture Frames. Methods of Mounting Pictures. Making Photograph Frames. Frames covered with Plush and Cork. Hanging and Packing Pictures. Smiths' Work. With 211 Engravings and Diagrams. Contents. Forges and Appliances. Hand Tools. Drawing Down and Up-setting. Welding and Punching. Conditions of Work: Principles of Formation. Bending and Ring Making. Miscellaneous Examples of Forged Work. Cranks, Model Work, and Die Forging. Home-made Forges. The Manipulation of Steel at the Forge. Glass Working by Heat and Abrasion. With 300 Engravings and Diagrams. Contents. Appliances used in Glass Blowing. Manipulating Glass Tubing. Blowing Bulbs and Flasks. Jointing Tubes to Bulbs forming Thistle Funnels, etc. Blowing and Etching Glass Fancy Articles; Embossing and Gilding Flat Surfaces. Utilising Broken Glass Apparatus; Boring Holes in, and Riveting Glass. Hand-working of Telescope Specula. Turning, Chipping, and Grinding Glass. The Manufacture of Glass. DAVID McKAY, Publisher, Washington Square, Philadelphia. HANDICRAFT SERIES (Continued). Building Model Boats. With 168 Engravings and Diagrams. Contents. Building Model Yachts. Rigging and Sailing Model Yachts. Making and Fitting Simple Model Boats. Building a Model Atlantic Liner. Vertical Engine for a Model Launch. Model Launch Engine with Reversing Gear. Making a Show Case for a Model Boat. Electric Bells, How to Make and Fit Them. With 162 Engravings and Diagrams. Contents. The Electric Current and the Laws that Govern it. Current Conductors used in Electric-Bell Work. Wiring for Electric Bells. Elaborated Systems of Wiring; Burglar Alarms. Batteries for Electric Bells. The Construction of Electric Bells, Pushes, and Switches. Indicators for Electric-Bell Systems. Bamboo Work. With 177 Engravings and Diagrams. Contents. Bamboo: Its Sources and Uses. How to Work Bamboo. Bamboo Tables. Bamboo Chairs and Seats. Bamboo Bedroom Furniture. Bamboo Hall Racks and Stands. Bamboo Music Racks. Bamboo Cabinets and Bookcases. Bamboo Window Blinds. Miscellaneous Articles of Bamboo. Bamboo Mail Cart. Taxidermy. With 108 Engravings and Diagrams. Contents. Skinning Birds. Stuffing and Mounting Birds. Skinning and Stuffing Mammals. Mounting Animals' Horned Heads: Polishing and Mounting Horns. Skin- ning, Stuffing, and Casting Fish. Preserving, Cleaning, and Dyeing Skins. Preserving Insects, and Birds' Eggs. Cases for Mounting Specimens. Tailoring. With 180 Engravings and Diagrams. Contents. Tailors' Requisites and Methods of Stitching. Simple Repairs and Press- ing. Relining, Repocketing, and Recollaring. How to Cut and Make Trousers. How to Cut and Make Vests. Cutting and Making Lounge and Reefer Jackets. Cutting and Making Morning and Frock Coats. Photographic Cameras and Accessories. Comprising How TO MAKE CAMERAS, DARK SLIDES, SHUTTERS, and STANDS. With 160 Illustrations. Contents. Photographic Lenses and How to Test them. Modern Half-plate Cameras. Hand and Pocket Cameras. Ferrotype Cameras. Stereoscopic Cameras. Enlarging Cameras. Dark Slides. Cinematograph Management. Optical Lanterns. Comprising THE CONSTRUCTION AND MANAGEMENT OF OPTICAL LANTERNS AND THE MAKING OF SLIDES. With 160 Illustrations. Contents. Single Lanterns. Dissolving View Lanterns. Illuminant for Optical Lan- terns. Optical Lantern Accessories. Conducting a Lime-light Lantern Exhibition. Ex- periments with Optical Lanterns. Painting Lantern Slides. Photographic Lantern Slides. Mechanical Lantern Slides. Cinematograph Management. Engraving Metals. With Numerous Illustrations. Contents. Introduction and Terms used. Engravers' Tools and their Uses. Ele- mentary Exercises in Engraving. Engraving Plate and Precious Metals. Engraving Monograms. Transfer Process of Engraving Metals. Engraving Name Plates. En- graving Coffin Plates. Engraving Steel Plates. Chasing and Embossing Metals. Etch- ing Metals. Basket Work. With 189 Illustrations. Contents. Tools and Materials. Simple Baskets. Grocer's Square Baskets. Round Baskets. Oval Baskets. Flat Fruit Baskets. Wicker Elbow Chairs. Basket Bottle- casings. Doctors' and Chemists' Baskets. Fancy Basket Work. Sussex Trug Basket. Miscellaneous Basket Work. Index. Bookbinding. With 125 Engravings and Diagrams. Contents. Bookbinders' Appliances. Folding Printed Book Sheets. Beating ana Sewing. Rounding, Backing, and Cover Cutting. Cutting Book Edges. Covering Books. Cloth-bound Books, Pamphlets, etc. Account Books, Ledgers, etc. Coloring, Sprinkling, and Marbling Book Edges. Marbling Book Papers. Gilding Book Edges. Sprinkling and Tree Marbling Book Covers. Lettering, Gilding, and Finishing Book Covers. Index. Bent Iron Work. Including ELEMENTARY ART METAL WORK. With 269 Engravings and Diagrams. Contents. Tools and Materials. Bending and Working Strip Iron. Simple Exercises in Bent Iron. Floral Ornaments for Bent Iron Work. Candlesticks. Hall Lanterns. Screens, Grilles, etc. Table Lamps. Suspended Lamps and Flower Bowls. Photo- graph Frames. Newspaper Rack. Floor Lamps. Miscellaneous Examples. Index. Photography. With Numerous Engravings and Diagrams. Contents. The Camera and its Accessories. The Studio and the Dark Room. Plates. Exposure. Developing and Fixing Negatives. Intensification and Reduction of Nega- tives. Portraiture and Picture Composition. Flash-light Photography. Retouching Negatives. Processes of Printing from Negatives. Mounting and Finishing Prints. Copying and Enlarging. Stereoscopic Photography, Ferrotype Photography. DAVID McKAY, Publisher, Washington Square, Philadelphia. HANDICRAFT SERIES (Continue^. Upholstery. With 162 Engravings and Diagrams. Contents. Upholsterers' Materials. Upholsterers' Tools and Appliances. Webbing, Springing, Stuffing, and Tufting. Making Seat Cushions and Squabs. Upholstering an Easy Chair. Upholstering Couches and Sofas. Upholstering Footstools, Fenderettes, etc. Miscellaneous Upholstery. Mattress Making and Repairing. Fancy Upholstery. Renovating and Repairing Upholstered Furniture. Planning and Laying Carpets and Linoleum. Index. Leather Working. With 162 Engravings and Diagrams. Contents. Qualities and Varieties of Leather. Strap Cutting and Making. Letter Cases and Writing Pads. Hair Brush and Collar Cases. Hat Cases. Banjo and Man- doline Cases. Bags. Portmanteaux and Travelling Trunks. Knapsacks and Satchels. Leather Ornamentation. Footballs. Dyeing Leather. Miscellaneous Examples of Leather Work. Index. Harness Making. With 197 Engravings and Diagrams. Contents. Harness Makers' Tools. Harness Makers' Materials. Simple Exercises in Stitching. Looping. Cart Harness. Cart Collars. Cart Saddles. Fore Gear and Leader Harness. Plough Harness. Bits, Spurs, Stirrups, and Harness Furniture. Van and Cab Harness. Index. Saddlery. With 99 Engravings and Diagrams. Contents. Gentleman's Riding Saddle. Panel for Gentleman's Saddle. Ladies' Side Saddles. Children's Saddles or Pilches. Saddle Cruppers, Breastplates, and other Accessories. Riding Bridles. Breaking-down Tackel. Head Collars. Horse Clothing. Knee-caps and Miscellaneous Articles. Repairing Harness and Saddlery. Re-lining Collars and Saddles. Riding and Driving Whips. Superior Set of Gig Harness. Index. Knotting and Splicing, Ropes and Cordage. With 208 Engravings and Diagrams. Contents. Introduction. Rope Formation. Simple and Useful Knots. Eye Knots, Hitches and Bends. Ring Knots and Rope Shortenings. Ties and Lashings. Fancy Knots. Rope Splicing. Working Cordage. Hammock Making. Lashings and Ties for Scaffolding. Splicing and Socketing Wire Ropes. Index. Beehives and Beekeepers' Appliances. With 155 Engravings and Diagrams. Contend. Introduction. A Bar-Frame Beehive. Temporary Beehive. Tiering Bar- Frame Beehive. The " W. B. C." Beehive. Furnishing and Stocking a Beehive. Obser- vatory Beehive for Permanent Use. Observatory Beehive for Temporary Use. Inspection Case for Beehives. Hive for Rearing Queen Bees. Super-Clearers. Bee Smoker. Honey Extractors. Wax Extractors. Beekeepers' Miscellaneous Appliances. Index. Ready Shortly : Electro Plating. Other Volumes in Preparation. DAVID McKAY, Publisher, Washington Square, Philadelphia. PATTERN MAKING WITH NUMEROUS ENGRAVINGS AND DIAGRAMS EDITED BY PAUL K HASLUOK HONOURS MEDALLIST IN TECHNOLOGY AUTHOR OF "HANDVBOOKS FOR HANDICRAFTS," ETC. ETC. PHI LA DELPHI A DAVID McKAY, PUBLISHER G10, SOUTH WASHINGTON SQUARE 1905 Lr.ry TS PREFACE. PRACTICAL PATTERN MAKING contains, in a form convenient for everyday use, a comprehensive digest of information, con- tributed by experienced craftsmen, scattered over the columns of WORK, one of the weekly journals it is my fortune to edit, and supplies concise information on the general principles and practice of the art on which it treats. Readers who may desire additional information respecting special details of the matters dealt with in this book, or in- structions on any kindred subject, should address a question to WORK, so that it may be answered in the columns of that journal. P. N. HASLUCK. La Belle Sauvage, London, September, 190?. F Ua cr 733815 CONTENTS. CHAPTER PAGE I. Foundry Patterns and Foundry Practice ... 9 II. Jointing-up Patterns 24 III. Finishing Patterns 36 IV. Circular Patterns 42 V. Making Core-boxes 50 VI. Coring Holes in Castings . .... . .59 VII. Patterns and Moulds for Iron Columns . . .83 VIIL Steam-engine Cylinder Patterns and Core-boxes . 93 IX. Worm Wheel Pattern 101 X. Lathe-bed Patterns . . . . . . .110 XI. Headstock and Poppet Patterns . . . .125 X IF. Slide-rest Patterns 135 XIII. Miscellaneous Patterns and Core-boxes . . .147 Index , . 158 LIST OF ILLUSTRATIONS. FIG. PAGE 1, 2. Pegside and Eyeside of Flask 12 3, 4. Square Flask 14 5, 6.-Oblong Flask 7. Flask ready for Vertical Pouring .... 8. Moulding Board 9, 10. Clamp .... 11. Moulding Tub 12-14. Moulding Trough . 15. Section of Mould . 16. Section of Trough . 17, 18. Rammiag Benches . 19. Runners in Mould 20. Halving 21, 22. Middle and Dovetail Half-checks .... 23. Dovetail . 24-26. Three-part Checks 27-29. Four-part Checks 30. Section of Metal Peg 31, 32. Metal Plate Dowe: 33. Round Plate Dowel 34. Cup and Peg Dowel 35.-Feather-edged Fillet 36, 37. Angle-bo ird 38. Inlaid Fillets . . . .vt ?9. Inclined Rib . . . .33 40. Leather Strip for Curved Fillet 33 41. Fillet Worked out of Flange 33 42-44. Feather-edged Fillets . 34 45. Fillet for Core-box with Loose Ends . . . .34 46, 47. Fillets Worked out of Solid 48. Iron for Searing Plain Sur- faces 49._Searing plain Bolt Holes . 50. Searing Holes for Cone- headed Screws 51. Searing Holes for Cheese- headed Screws . 52. Searing Holes in Strainer Core-box .... 53. Searing Hole of Convex Section from Opposite Sides 54. Knob Pattern with Chuck- ing Piece .... 55. Undercut Knob Pattern . 56. Correct Shane for Pattern 57. Pillar with Chucking Pieces at Each End . 5S. 59. Ring Casting . 60. Template for Segments 61. Sawing-board .... 62. Segments Tightened with Dog 63. Building Pattern of Vary- ing Section .... 64. Segments built up on Disc 65. Plate for Shaping Pegs . 66. Circular Pan, with Cover . 25 26 . 26, 27 . 27, 28 Dowel 28 . .29 . 29 . 31 . 31 . 32 FIG. PAGfi 67. Axle for Strickle ... 48 63. Strickling Shell ... 49 69. Edge of Strickle ... 49 70. Core-box for Circular Core 50 71. Half of Core-box, showing Dowels .... 51 72. Core-box for Bend-pipe . 51 73. Template for Working Cir- cular Core-boxes . . 51 74. Working out Circular Core-box with Set-square 52 75. Fixing Steel Plate in Corner of Set-square . 52 76. Internal Flange fitted into Core-box . . . .53 77.-Chamber Core ... 53 78. Core-box for Chamber-core 54 7?. Core-box witli End of Small Diameter . . 54 80, 81. Rectangular Core nd Core-box .... 55 82. Built-up Box for Large Rectangular Core . . 56 83. Half Box for Large Cir- cular Core . . . .57 84, 5. Symmetrical and Un- symmetrical Cores . . 57 E6. Core for Bend-pipe with Branch .... 58 87. Core-box for Fly-wheel . 58 88, 89. Cylinder Cover Casting 59 90. Cylinder Cover Pattern . 60 91, 92. Core-box for Cylinder Cover 61 91 Mould for Cylinder Cover. 61 94, 95.-Casting of Engine Cylinder .... 63 96, 97. Engine Cylinder Pat- tern 64 93, 99. Mould for Engine Cylinder .... 65 100-104. So uare Prints . . . 66 105, 106. Steam Chest Casting . 67 107-109. Steam Chest Pattern . 68 110. Mould for Steam Chest . 69 111, 112.-Casting of Hand Cap- stan Boss . . . .69 113, 114. Hand Capstan Boss Pattern . . . .70 115, 116. Mould for Hand Cap- stan Boss . . . .70 117, 118. Bracket Casting . . 71 119, 123. Bracket Pattern with Core Prints . . . 72 12t.-F ot of Bracket Pattern 73 122, 123. Sections through Cored Mould . . 73, 74 124, 121. Core-box for Foot of Bracket .... 74 126, 127. Stopping-over Board for Cores . . . .75 128, 129. Bracket Casting . . 76 130, 131. Bracket Casting Pat- tern with Core Prints . 76 Pit AC TIC A L PATTERN MAKING. FIG. PAGE 132, 133. Alternative Method of Arranging Pocket Prints 77 134, 135. Pipe Casting with Square Holes in Flanges 78 136, 137. Pattern of Flange for Pipe Casting with Prints 78 138. Mould for Pipe Casting with Cores Inserted . . 79 139, 140. Stopping-over Piece . 79 141, 142. Bracket Casting with Slot Holes in- Foot . . 80 143. Prints on Foot of Bracket Pattern . . . .80 144. Patterns united with Con- tinuous Print . . .80 145, 146. Double Bracket Cast- ing 81 147, 148. Double Bracket Pat- tern 82 149-153. Column Pattern . 84, 85 154. Drag for Casting Columns . 87 155-157. Mould for Column 87, 89 153. Pouring Arrangements . 89 159. Longitudinal Section of Small Steam Cylinder . 94 160, 161. Cross Sections through Exhaust Port and Steam Passage . . . .94 162, 163. Half Pattern of Core- box for Cylinder . . 96 164, 165. Half Body Core-box for Small Steam Cylinder 96 166, 167. Half Core-box for Ex- haust Port . . . .96 168-170. Steam-chest Core-box . 97 171, 172. Steam-inlet Core-box . 93 173-176. Steam-port Core-box . 99 177, 178.-Loose Piece for Valve Spindle Stuffing-box . 100 179, 180. Half Core-box for Valve Spindle Stuffing- box 100 181. Worm Wheel Casting . 101 182, 183.-End View and Section of Worm Wheel Casting . 102 184.- Marking Section of Worm Wheel 102 185, 186. Half Pattern of Worm Wheel Body Glued up Roughly . . . .103 187, 188. Jointing Worm Wheel Pattern . . . .105 189. Turning Outside of Rim by Template . . . 105 190. Tooth Block Glued on Rim 106 191. Turning Tooth Points by Template . . . .106 192. Turning Inside of Rim by Template . . . .106 193. Forms of Teeth on Worm Wheel 107 194. Template for Marking Tooth Curves . . . 107 195. Cutting Wheel Teeth . . 108 196.-Worm Wheel Pattern . 109 . Lathe-bod Casting . 110 | FIG. PAGE 200, 201. Lathe-bed Pattern . Ill I 202, 203. Cross-bar and Foot of Lathe-bed Pattern . . Ill 204-211. Gap Lathe-bed and Pat- tern . . . 114, 116. 113 212. Fitting Bearers with Dove- tails 119 213-223. Core-boxes for Taking out Portions of Gap Lathe-bed . . . 120-123 224-226. Back-geared Headstock Pattern . . . .126 227. Round Parallel Prints . 127 223. Curved Horns for Mandrel Bearings .... 127 229-234. Headstock Patterns 123, 129 235, 236. Plain Square Core-box 129 237-239. Lathe Poppet Pattern . 130 240, 241. Moulding Barrel for Lathe Poppet . . .131 242. Barrel for Lathe Poppet. with Dowels and Hollows 131 243. Turning Poppet Barrel . 131 244 250. Lathe Poppet Pat- tern .... 132-134 251-255. Slide-rest Saddle Pat- tern .... 136-139 256, 257. Core-box to Form Re- cess for Surfacing Screw 139 258, 259. Core-box for Sliding Pinion Spindle . . .140 230 262. Surfacing Slide Pat- terns 140 233, 264. Ring Core-box for Surfacing Slide . . 140 265. Core-box to Form Recess for Screw .... 142 266. Half Box Opened in Joint Face 142 267. Transverse Section of Core-box . . . .142 263-270. Swivel Slide Pattern . 143 271, 272. Top Slide Pattern . 144 273, 274. Apron Pattern . . 145 275, 276. Screw-down Valve . 148 277. Body Pattern for Screw- down Valve . . . .149 278. Core-box for Screw-down Valve 149 279. Valve Top Cap Pattern . 150 280. Core-box for Valve Top Cap 150 281, 282. Nut Pattern and Core- box 151 283. Knob Pattern . . .151 284. Core-box for Knob . . 151 235-287. Globe Valve Core-box 152, 153 288. Template . . . .153 289, 290. Turned Segments . 154 291, 292. Working Segments 154 293. End of Segment . . .155 294, 295. Block for Ends of Seg- ments 155 296-298. Bull-nose Plane . . 156 299, 300. Core-box for Bull- nose Plane , , .157 PRACTICAL PATTERN MAKING. CHAPTER I. FOUNDRY PATTERNS AND FOUNDRY PRACTICE. A FOUNDRY pattern is a counterpart of a casting, and is used to form the mould into which the molten metal is poured. Pattern-making is thus a very important part of foundry work, and the pattern-maker must be a craftsman of experience and of more than ordinary intelligence. Pattern-making is done usually in a shop having only two or three workmen, each one of whom must be able to make any description of pattern that may be wanted. Thus one man soon comes to command a wide range of the art, and is obliged to be conversant with a great number of processes widely different in character the one from the other. The competent pattern maker has a knowledge of practical plane and solid geometry and of mechanical drawing ; he is constantly required to lay upon an uneven angular sur- face lines which the ordinary draughtsman can get much more easily on the smooth surface of paper. He must know the nature of the woods or other material used, and be able to construct and form with accuracy any con- ceivable shape of body, so that it will best stand the strains of the work required, and keep its size. He must understand how the pattern can best be moulded, since he is required to decide how much of a pattern is neces- sary, and where and how to make the parting, taper, prints, core-boxes, etc. The object of a pattern being to facilitate the making of a mould, the pattern-maker must know the capacity of the moulder and his appliances. Some moulds can be made more cheaply without a pattern by the use of strikes, others with a combination of strikes and parts of pattern, 10 PRACTICAL PATTERN MAKING. others with cores, while others require a full pattern of the size and shape of casting required, plus the allow- ance for shrinkage. Thus a pattern may be made to cost more in the pattern-making, and less in the moulding, or more in the moulding, and less in the pattern-making, according to which workman can do the work the cheapest. The number of castings expected to be made will also affect the construction and finish of a pattern. For instance, if twenty castings are required from one pattern, and one hour's work more on the pattern would save the moulder five minutes on each mould, there would be an economy of forty minutes saved by the extra hour spent in pattern work ; while if there was but one casting to be made, and the one hour's pattern work was still put upon it, there would be a loss of fifty-five minutes, seeing that the moulder was saved but five minutes' work. After the pattern-maker has considered all the requirements of the moulder, he must follow the casting in his mind into the machine shop, and consider the shrinkage, finish, and the ultimate strength and soundness of the parts. A mould is an impression in sand shaped to correspond with the required casting, and it is best produced by ramming up in the sand a pattern or model of the article required. This pattern must, of course, be withdrawn from the sand before the mould can receive the molten metal, and the pattern must therefore be so constructed that it may be withdrawn from the sand without disturbing the mould. The non-appreciation of this essential is the cause of frequent indifferent and useless patterns being made. The first important point in pattern-making is that a pattern must be tapered to allow for withdrawing it from the mould (exceptions will be dealt with in their place). A well-tapered pattern readily "draws"; the act of withdrawing a pattern is known as the "draft." Most works on pattern-making give detailed information on the many varieties of woods used, describe' the tools employed, and attempt a course of instruction in the use of both materials and tools. But that is quite outside the present scope, and, indeed, is quite unnecessary here. Pattern-making is such an intricate craft that the whole of the space here available is necessary for an adequate con- FOUNDRY PATTERNS AND FOUNDRY PRACTICE. 11 sideration of the methods of forming the patterns them- selves. Detailed information on tools and materials must be looked for elsewhere. The whole subject of wood- working is dealt with comprehensively in " The Handy- man's Book of Woodworking," a book of 760 pp. produced under the direction of the editor of this work. Wood for pattern-making should be well seasoned, and practically all kinds are in use for the purpose. Large, long and flat patterns are made of white or yellow pine, on account of its lightness, cheapness, and freedom from warping and splitting, but it has, of course, the other dis- advantage of being soft and more liable to receive injury when made up. Choice Canadian red pine is harder, but should be selected as free from knots and turpentine as possible. Still harder is white fir (spruce fir), which is admirable for large wheel patterns ; the harder the wood, the finer does it look when sawn, but the working of this material is troublesome when catfaced, that is, when some parts are smooth and some rough. Teak is light, strong and durable, and easily worked, but punishes the tools a little, and is somewhat liable to split. Any part of a pattern which has to be turned may be made of beech, which has a uniform grain. Much elm, oak, maple and sycamore is used also. For small patterns the Germans use cherry-tree wood, well seasoned, because it is hard and close grained ; but in England, mahogany (chiefly baywood) comes into use for small work, and will be found to suit nearly all patterns ; it warps less than other woods, shrinks but little in drying, and can be worked at the ends easily, its corners keeping sharp ; but the tools used must be in good condition. Boxwood also is an excellent wood for small patterns. A very important point in pattern-making is the duo allowance for shrinkage. Castings in iron vary in shrink- age, according to their mass ; for. metal 1 in. in thickness, allow T ^ in. to the foot in making the pattern, while thinner castings require more, and thicker a shade less allowance in proportion. Brass shrinks rather more, and in. may be substituted for the ^ in. afore-mentioned. For castings under 1 ft. long, shrinkage need scarcely be taken into consideration ; 12 PRACTICAL PATTERN MAKING. the rapping of the pattern by the moulder usually suffices. This rapping, which is done to loosen the pattern before drawing, is usually done by boring a hole in the pattern, and inserting a spike in the same, and then rapping the spike on all sides with a hammer. This necessarily tries the strength of the pattern, and if many castings are required off one pattern, it is well to cut a small mortise when the rapping hole is wanted, and insert therein a small iron plate with a hole in it, thereby saving the wood from the actual contact with the spike. In making patterns of articles which have to be worked up before use, it is well to allow sufficient metal for the process. A file or lathe will easily remove a superfluous Fig. 1. Fig. 2. Figs,. 1 and 2. Peg-side and Eye-side of Flask. T ' ff in., but no mechanical method can satisfactorily add that amount if it be lacking at the first. Metal patterns are used when a large supply of castings is required. Iron, brass, or white metal is commonly used for patterns. Core-boxes are made of the same material as patterns. Iron has to be protected from rusting by varnishing or beeswaxing ; brass and white metal do not need protection. As the thickness of metal is often shaved down as slight as possible, plaster of Paris is frequently used to obtain exact thickness before casting the final pattern or core-box. An alloy of lead and tin is also used for patterns. The patterns should be chased up and finished to the very finest degree, and if made in two or more parts the necessary fitments for fixing them should be soldered on, so that the portions when cast may FOUNDRY PATTERNS AND FOUNDRY PRACTICE. 13 fit together easily. Exact making and finishing of the patterns will be advantageous, as better castings will result, and the fitter's work is rendered very much easier. An outline of foundry operations will now be given to enable the worker to construct patterns intelligently, and with their ultimate use well in mind. The sand moulds into which the molten metal is poured are made in flasks or moulding frames. These consist of a pair of shallow frames, without top or bottom, and usually made of cast-iron, having lugs on the one side as at A (Fig. 1), and lugs with holes in on the other side as B (Fig. 2). Wooden flasks are used in brass foundries*, i fe -. 3. J?ig. 4. Figs. 3 and 4. Plan and End of Square Flask. though they are seldom seen in English iron foundries. The fitting of the pegs and the eyes of each pair of frames forming a moulding box must be very exact, so that there may be no shifting. In the pair of frames forming the brass founder's flask, one is called the peg-side, while the other is the eye-side. In iron foundries the two parts are called the cope and drag, and these are fitted with lugs having matching pins and holes, the two being either cottered together, or weighted and poured while laid horizontal on the sand floor. There is one type of brass founder's flask, however, which is not employed by the iron founder, that in which the mould is poured while the flask stands vertical, or in a slightly sloping position. Figs. 3 and 4 II PRACTICAL PATTERN MAKING. show a flask used by brass founders and iron founders, and made in sizes from about 9 in. to 18 in. square, usually without bars or stays. Such flasks are poured while laid \2/ \2/ Fig. 5. Fig. 6. Figs. 5 and 0. Plan and Section of Oblong Flask, horizontal. Figs. 5 to 7 show the type of flask which is used for vertical pouring. These flasks usually are jointed, and have pins in the lugs. The sand is contained between moulding boards (Fig. 8), Fig. 7. Flask ready for Vertical Pouring. upon which the flasks are rammed, and by which the mould is confined during pouring by means of clamps (Figs. 9 and 10). The boards are of deal or oak, and the FOUNDRY PATTERNS AND FOUNDRY PRACTICE. 15 ends are tongucd to prevent warping. They are from 1$ in. to 1| in thick. Flasks that are made of wood are strongly dovetailed or tenoned, and clamped at the corners, and Fig-. 8. Moulding Board. the top end, which is pierced with holes, is made of iron, or protected with iron. A flask made wholly of iron costs rather more in the first place than a wood flask, but it is practically ever- lasting, besides being more rigid. In Figs. 5 and 6 a rib is shown cast round the edges of the flasks next the faces, against which the boards are clamped. In some American flasks the section is grooved in order to confine Fig. 10. Figs. 9 and 10. Side and Edge Views of Clamp. the sand more efficiently. The clamps are of wood, and so are the screw nuts shown in Figs. 9 and 10. In brass foundries the moulding tub to contain the sand 16 PRACTICAL PATTERN MAKING. usually consists of an iron casting about 6 ft. long, 2 ft. wide at the bottom, and about 2 ft. 3 in. at the top by 15 in. deep. This is placed on brick supports, one at each end, so that its top edge is about 2 ft. 3 in. from the floor (see Fig. 11). In smaller foundries very frequently the work bench is made a part of the moulding tub, the advantage being that the sand is handy in the tub beneath the bench, which forms the cover of the tub. When a plain bench is employed, the sand is brought in small quantities from the sand bins or tubs, and placed in a small heap at the back of the bench. The moulding trough of the brass founder is shown by Figs. 12, 13, and 14, which illustrate a plan, side elevation, and end eleva- tion ; this tub affords at once a receptacle for sand and . 11. Moulding Tub. a work bench. It stands against the wall, and is about 2 ft. 6 in. high and wide, and of any length. The tub shown is for one man, the work being done upon the sliding board A, beneath which is the trough, which contains the sand. The trough is made of deal of about ij in. thick, dovetailed or nailed at the corners, and tapered at front and sides for convenience of shovelling out the sand. When preparing a mould the sand is first tempered by the addition of water, and passed through a sieve of about five or six meshes to the linear inch. Raw sand must be employed, as used or burnt sand does not possess the adhesiveness necessary for the purpose, since it contains proportions of charcoal and other substances, such as peaflour, brickdust, etc. The sharp edges of the sand grains too have been rounded by use ; they cannot, there- fore, wedge together so firmly. FOUNDRY PATTERNS AND FOUNDRY PRACTICE. 17 The moulding of the odd-side is begun by taking an eye-side frame, and placing it on a board. The inside of this frame is dusted over with parting sand, and then the side is filled with black sand, to which some raw sand has been added. This is rammed down tight, first with the palms of the hands, then with the knuckles, and, lastly, with a wooden mallet ; occasionally the workman will tread it down firmly as the final operation. The sand is then scraped level with a bar of iron, a moulding board is laid on the top, and the frame with its entire contents is inverted. The patterns to be moulded are now laid very carefully 18 PRACTICAL PATTERN MAKING. on the face of the mould, and the dust bag shaken over them ; this leaves on the sand a clear outline of the patterns. These are now lifted off, and the sand is care- fully cut away, leaving the patterns embedded half-way. A peg-side frame, to fit on the odd-side, is placed on the eye-side, as illustrated by the sectional view (Fig. 15), and then parting sand is dusted over the sand, a mixture of raw and black sand is laid over the half embedded patterns, and the mould filled with black sand. The whole of the sand in the flask is now carefully rammed as tight as possible, as described above. A second mould- ing board is placed on the top of the flask and well hammered to loosen the patterns, and the whole is turned over and again hammered. The patterns will now be in the eye-side, which is ready for moulding from. Fig. 16 shows a moulding trough in section in which the flask is supported on boards that may be shifted along. Fig. 15. Section of Mould. For making the peg-side mould, the process is repeated, a peg-side frame is placed on the eye-side, sand pressed in as before, covered by a board, and the whole inverted. The patterns are loosened by hammering on the top board, and the odd peg-side, which now bears perfect impressions of one-half of each pattern in the flask, is taken off, leaving the patterns in the eye-side. The frame called the peg-side is now taken and placed on the eye-side, sand is placed in the mould and well rammed, as in previous operations ; the peg-side is removed, leaving the patterns in the eye-side ; the odd-side is brought and placed on the eye-side, and the whole inverted. The patterns are loosened by hammering, the eye-side is taken away, and, the patterns being left in the odd peg-side, all is ready for use again, and thus the odd-side can be repeatedly used for moulding purposes. In many cases where large quantities of castings of similar work are (required, there are two other methods adopted in moulding, namely, platework and gatework. FOUNDRY PATTERNS AND FOUNDRY PRACTICE. 19 These methods are excellent, and might be adopted with advantage to a much greater extent. They are suitable for use either in hand moulding or in conjunction with a moulding machine. The chief advantage of machine- over hand-moulding is that a perpendicular lift is ensured, thus diminishing the risk of the breaking down of sand in a deep face. In platework the patterns are attached to a match plate or board, while in gatework a number of patterns sufficient to fill the standard flask are riveted or soldered to the gate-piece, practically forming one pattern. Platework and gatework have each their own merits, but generally it is better to put the patterns on plates than Fig. 16. Section of Trough. to gates, whenever it is possible to do so. Bib-cocks, plugs, handles, stems, globe and other valves, the parting lines of which are straight, can all be made on the plate principle, thereby saving the time that would be expended in making odd-sides, trimming the joints of the mould, etc., necessary with gated patterns. There are several kinds of plated patterns, the methods of moulding being different in certain cases. The simplest plated work is that in which two portions of a pattern are put on opposite sides of a plate, wood being employed. The two portions of the pattern are precisely like those which would be used if there were no plate interposed, these portions being those which go into the opposite halves of the flask, the thickness of the plate being 20 PRACTICAL PATTERN MAKING. immaterial. In moulding, the two sides of a flask are rammed on opposite sides of the plate, being cottered together through it, and the flasks being turned over for the ramming of opposite sides. A superior and more permanent pattern plate is made of iron or brass. In this the opposite portions of the pattern are prepared as though for moulding in the ordinary way, and then they are screwed to the opposite sides of a metal plate about f in. or \ in. in thickness, and the flasks are rammed from the opposite sides of the pattern. In another method the two halves of a pattern are moulded on a separate plate instead of on opposite sides of the same one, and the flasks are rammed apart, and are only brought together when being closed for pouring. In this method also wood and metal plates are both used. Each of these types of plates is used either with flasks rammed in the usual way or upon a moulding machine. Interchangeable flasks are almost a necessity in platework, as the plate must fit on the peg-sides of flasks, which are thus used as dowels. The advantages and disadvantages of platework and odd-side moulding may be summarised. Patterns once put on a plate are only suitable for using in groups, while patterns moulded in an odd-side can be made in any groupings. This latter is a great advantage, when the numbers required off given patterns vary from time to time ; work put on plates should be arranged so that sets shall be completed without any parts being in excess on the one hand, or insufficient in numbers on the other. To mount metal patterns on plates is costly, and is only economical when large quantities of castings are wanted. The fitting must be done most accurately, otherwise there Avill be lapping joints and cores out of truth. Small brass work can only be done cheaply and well by the adoption of odd-side or plate moulding, and the choice must be controlled by circumstances. When the platework or gatework method is adopted, the advantages are that the time of bedding a pattern temporarily into its cope, and of making the joint face and sloping joints on which to ram the drag, is wholly saved. The time in cutting runners is also saved. These occupy a good deal of time when a number of patterns are moulded in one flask, and FOUNDRY PATTERNS AND FOUNDRY PRACTICE. 21 especially when they are of shapes involving the making of numerous sloping and curved down-joints. These methods of moulding are generally practicable when doing a large run of standard work, but they are seldom avail- able in small foundries, and therefore the odd-side method is generally preferred in these. The sand floor usual in a foundry is useful for bedding the heavier work, which is covered with copes. It is also used to lay the flasks upon when moulded and prepared ready for casting. As the sand is receiving constant additions from the new sand used in facings, a depth of from 3 in. to 6 in. will be sufficient to lay down at starting. It is employed over and over again for box filling, re- Fig-. 17. Ramming Bench Bolted to Wall. Fig. 18. Ramming Bench Supported by Legs. serving the new special sand for facings that is to say, for the stratum of sand which is immediately next the pattern to a thickness ranging from in. to 1 in., hence called pattern facings. In the smallest moulds facing sand alone would be employed. Partings for brass moulds are made of burnt red sand or of red brickdust. Peameal dusted over is used for facing green sand work, both light and heavy. So are flour, powdered chalk, whiting, and sometimes charcoal. Lime mixed with water is used for facing dry sand moulds and cores for brasswork. In a small foundry it is necessary to have a bench, on which moulds except those occasionally made in the sand floor will be rammed. The bench will be of dimensions most suitable to the work required. It may be of iron, but 22 PRACTICAL PATTERN MAKING. wood is suitable, 3-in. deals being supported on wood brackets, the latter being, if practicable, bolted to the wall with through bolts and wall plates, as shown in Fig. 17. If this cannot be done, the support may be afforded in the manner illustrated in Fig. 18. Three 11-in. or 9-in. deals will afford sufficient width of bench for the average run of brass founders' work. When moulding a large number of small patterns in a single flask, they, with their runners, must be so arranged that the metal shall not cool before the moulds farthest from the ingate are reached. To this end it is desirable to maintain something like uniformity in size and mass of the several patterns included in any one flask ; to have Fig. It). Arrangement of Runners in Mould. the runners of sufficient area ; and to pour the metal sufficiently hot to ensure its running to the farther end of the mould. There are two general arrangements of runners. In the one they pass from mould to mould in a flask, the metal running through the successive moulds to the last one. The other is that in which the metal (runs down a ridge runner, and passes thence through sprays to the moulds arranged on one side, or on both sides, to right and left. A ridge of large area and small sprays is the ideal arrangement. This is shown in Fig. 19. The patterns are so arranged in a flask that during the pouring some amount of pressure is imparted by a head of metal. Generally, this takes the form of a continuation of the head of the ingate a few inches above the front or top FOUNDRY PATTERNS AND FOUNDRY PRACTICE. 23 mould. The more dense the metal is required the deeper must this head be. Castings for hydraulic work, which have to stand test pressures of 1,000 Ib. or more to the inch, have to be very dense. If sufficient head is given above the mould, it is not necessary to cast supplementary heads upon the castings themselves. Such heads are sometimes cast on the ends of pump liners and other cylindrical work ; but that is more with a view to take the sullage which gathers in a deep mould. Before the moulds are finally closed, channels must be cut in them connecting the various small impressions with the runners and gates, in order to convey the molten metal to the necessary parts of the moulds. A very good way of making the main ingate or git-hole is to procure a thin piece of tinplate tubing, and with it cut a hole through the sand in the top box to the parting, after- wards withdrawing the tube and tapering off the mouth or top part of the hole to a trumpet or bell shape, and form- ing also a small air-hole from the top box, at the other end, through to the parting. This allows the escape of the gases which generate within the mould whilst the metal is being poured, and prevents the casting turning out blown, or damaged by small holes. The channels must be sufficiently large to allow the metal completely to fill the impression made in the mould, but must not be larger, or waste of metal will result. It is usual to put the runners or channels in the eye-side, while if any cores are used they are placed in the peg-side. The moulds, even in common work, are usually dried a little by placing before a stove fire, although this is not absolutely necessary if the impressions have been carefully prepared and dusted with charcoal, it must not be omitted if fine castings are required. If both sides of the casting be required fine, both sides of the mould must be dried. When sufficient moulds have been made to con- stitute a heat say five or six they are placed against the spilling trough, and are then ready to receive the molten metal. Other details of foundry work necessary to the proper understanding of the craft of the pattern maker will be given as occasion demands. 24 CHAPTER II. JOINTING-UP PATTERNS. THE halving joint is largely used in pattern-making, and the method of joining two pieces of wood together by this means is apparent from Fig. 20. In making this joint, mark one side of each of the pieces to be joined to indicate the face side. Set a gauge to half the thickness of the stuff, and gauge lines on the edges where the pieces are to be placed. Always gauge from the face side, so that even if the gauge was not set exactly to half the thickness the joint will still come even. Screw the pieces together, and then, if the fit is good, take them apart, put on glue, and screw them together again while the glue is hot. Fig. 20. Halving. Corner half-checks are generally cut the whole width of the stuff, as in Fig. 20, but for middle pieces the check is sometimes made short, so as to leave a portion of the timber the full thickness, adding thereby to the strength of the frame, as in Fig. 21. The dovetail half-check is shown in Figs. 22 and 23 ; its use is not to hold the pieces together (the glue and screws do that) but to enable a portion of the frame to be hollowed out, and yet not reduce the cross-grained parts (where the pieces butt together) so much as to make them weak and brittle. The ordinary half-check answers this purpose also, pro- JOINTING-HP PATTERNS. 25 vided the tongue and the space which it fits be narrower than the stuff is wide. Other joints used in pattern-making are the simple butt joint and mitre. Wheel patterns necessitate some joints that are out of the common. Fig. 21. Middle Half -check. The three-part check (Figs. 24 to 26) is used for wheels with six arms, it allows three pieces to be joined together in the thickness of one. To make it, find the centre in each of the three pieces ; with a radius equal to half the width of a piece, describe a circle on one side of the top and bottom pieces, and on both sides of the middle piece. Set a bevel to 60, and with it draw lines touching the circles, as shown in the figures. Divide, by gauge lines, the thickness of the pieces into three equal parts. Let all the portions of the pieces be cut away as shown. The middle piece is to be cut in on both sides as illustrated, Fig. 22. Dovetail Half-check. leaving one-third part in the centre. Cut away the top piece at the part represented by the cross shading for a depth of two-thirds of the thickness. The four-part check (Figs. 27 and 28) is the joint used for making an eight-arm wheel. As before, circles are 26 PRACTICAL PATTERN MAKING. described on one side of the pieces shown by Figs. 27 and 29, and on both sides of that shown by Fig. 28. With a bevel set to 45, draw lines touching the circles. Three- Fig. 23. Dovetail. quarters of the thickness of the piece shown by Fig. 27 must be cut away as illustrated. The two middle pieces are exactly alike on one side. The part cross-shaded must Fig. 24. Three-part Check. be cut down to half the thickness ; the little corners and the other side are cut down for a quarter thickness. The cross-shaded part shown in Fig. 29 is cut down for three- Fig. 25. Three-part Check. quarters of the thickness ; the corners shown lightly shaded are cut down one-quarter only. In the construction of patterns, glue should be used J01NTING-UP PATTERNS. 27 as little as possible. It frequently swells out when the damp sand comes into contact with it, and a glued-up Fig. 26. Three-part Check. pattern which possibly has taken hours to prepare often comes to pieces almost the first time of using. As far as possible use joiners' brads, or, better still, slender steel Fig. 27. Four-part Check. "wood" screws. When, however, glue is necessary, only the very best should be used ; have it thin and fresh. A little quick-drying linseed oil, well stirred in while the glue is . 28. Four-part Check. quite hot, increases its resistance to moisture ; but even then a coat or two of a good oil paint is necessary to protect the joint from the moisture arising from the sand. 28 PRACTICAL PATTERN MAKING. It is frequently desirable to make a foundry' pattern or a core-box in two parts, so that, while one part cannot slide upon the other, it may readily be lifted at right angles to the joint. This end is attained by the use of dowels. Fig. 29. Four-part Check. The most elementary form of dowelling consists of circular wooden pegs fitted into holes bored with a centre- bit. If the depth of each half pattern is not considerable, the pieces may be clamped together, and a hole bored through the top and partly into the lower piece. A hard- wood peg is driven through the top half until it protrudes from % in. to f in. ; the projecting part is then slightly tapered towards the end, so that it is free from the hole immediately it is lifted. Of course, a dowel should fit so that no perceptible lateral motion shall be possible. For permanent patterns, malleable cast-iron dowels, such as are shown in section by Figs. 30 and 31, and in plan by Fig. 32, are generally used. These consist of pairs of plates, one (in Fig. 30) carrying a turned peg, the other Fig. 30. Section of Metal Peg Dowel. (Figs. 31 and 32) having a hole into which the peg easily fits. Each has countersunk holes for the screws which fasten it to the core-box or pattern. The upper plate has two or more sharpened projections, usually at the corners of the plate (see Fig. 30). JOINTING- UP PA TTERNS. The plate dowel (Figs. 31 and 32) being laid in position, its outline is scribed upon the wood. The plate is then removed, a hole bored in the centre of the space marked, and a recess cut so that the top surface of the plate when fastened down sinks slightly below that of the wood. The O Fig. 32. Figs. 31 and 32. Sections of Metal Plate Dowel. peg dowel is then placed in position, the other half of the pattern is laid upon it, and a sharp blow struck upon the wood. The projecting spikes therefore fix the position of the peg dowel, which may then be inserted and fastened as before. Usually, at least two pairs of dowels are required, and in many cases more ; in such circumstances, if misplaced in the least degree, the dow-els may bind, or even refuse to enter the holes when the two parts of the pattern are brought together. This may sometimes be remedied by a sharp lateral blow upon one of the dowelled pieces of wood when they have been forced together. O, Fig. 33. Hound Plate Dowel. To find out where the binding takes place, smear the sides of the hole with red-lead and oil ; the peg is then forced into it by a blow, and, on examination, shows where the red-lead has adhered. The dowel is then moved to relieve that part. 30 PRACTICAL PATTERN MAKING. Some workmen insert all the plate dowels, then lay in place all the peg dowels, and mark them at one blow ; but it is better to mark and insert the peg dowels one by one, as then any inaccuracy may be detected and corrected as it arises. Dowels of this type are sometimes made of stamped brass, but are of little service if the pattern is roughly or frequently used. Dowels of the shape shown in Fig. 33 may be let into the wood by making centre-bit holes of the same diameter as the circular parts of the plate, spikes on the bottom of the plate marking the centres required. Small patterns sometimes have brass dowels as shown in Fig. 34. The peg carries a short stem on which depressions are turned to lock into the wood. In a better kind the stem is screwed, and a slot at the end of the peg enables it to be inserted with a screwdriver. Rings are also turned on the outside of the ferrule or socket. To insert these dowels a hole is bored, into which the cup dowel may be driven tight, but just before it is driven home the other piece is laid over it, and receives a blow which imprints upon it the shape of the projecting part of the cup dowel. The latter may now be completely driven home, and the peg inserted in the centre of the circle thus marked. An alternative method is to place between the surfaces household pins whose heads 'occupy the places selected for the centres of the dowels. A sharp blow presses the head of each pin into both pieces of wood, and marks the centres for the boring tools. . The joint face of each half of a pattern should have screwed upon it a stout rapping plate of wrought- or malleable cast-iron, having two holes, one tapped for a lifting screw, the other clear for a rod by which the moulder loosens the pattern in the sand preparatory to withdrawing it. The top of these plates should be, say, -/g in. lower than the surface of the wood, as the rapping burrs the edges of the hole. If the pattern is small enough to be lifted by one hand, the lifting hole should be vertically above the centre of gravity of the pattern. This point may be found experimentally by driving in a bradawl and suspending the pattern in the hand. When screws are used to connect parts of a pattern, their heads must be made flush, particularly where they JOINT1NG-UP PATTERNS. 31 would slide upon the sand during the lift. If the thickness of the wood through which the shank of the screw passes is not less than | in., the neatest method is to make a centre-bit hole and sink the head of the screw below the surface. Wooden plugs are then glued in and cut off flush. With thin stuff the holes are countersunk, the screw head being very slightly below the surface ; this depression, with the slot in screw head, is filled with ordinary putty. A paste made of whiting and shellac varnish hardens quickly, but when mixed it must be used at once. W r hen angles in a casting are left square, the strength of the casting is much less than when filled in with a Fig. 35. Feather-edged Fillet. Fig. 34. Cup and Peg Dowel. curved fillet. This is due to the crystallisation of cast-iron when cooling. The tendency of the crystals to form with their axes at right angles to the cooling surface of the mould causes a weak junction between the two sets of crystals when two parts of a casting are inclined to each other. The introduction of the fillet gets rid of this weak- ness. Moreover, the additional metal is an advantage at the angle where the regular formation of crystals is inter- fered with. Practically it is an advantage to the moulder by relieving him of a fragile salient angle of sand. For straight lengths of filleting, the usual practice of the pattern maker is to plane strips of wood to a triangular section, which are then hollowed out with a round-soled plane, as in Fig. 35. This is termed "feather-edged" 32 PRACTICAL PATTERN MAKING. filleting, or "angling." If the angle A is slightly more obtuse than a right angle, the fillet will fit close to the corner and reduce the tendency of the edges to curl up. Moreover, the angle in the pattern is seldom or never Fig. 36. Fig. 37. Figs. 36 and 37. Angle-board for Planing Filleting. square itself owing to the necessity of tapering for with- drawal from the sand. Figs. 36 and 37 show section and side elevation of an angle-board which is used for planing the filleting. Two chamfered strips are fixed together ; a stop of hardwood A is dovetailed in at the front end, and toward the real a cross saw-cut B is made for convenience in cutting off lengths. The bottom edge is recessed for working smaller sizes. With feather-edged filleting it is impossible to finish off the edges to a curve tangential to the adjoining sur- Fi?. 3S. Inlaid Fillets. faces, for this would mean working sharp, fragile edges. In patterns of the most perfect finish and durability, fillets may be inlaid as in Fig. 38. This form would be desirable in such a case as is shown at A (Fig. 39), for a JOINTING-UP PATTERNS. 33 feather-edged fillet here would be at once fragile and clumsy. In this case the fillets are of different curvature, the most shapely finish being obtained by taking tangents at the same height above the horizontal part. Fig. 39. -Inclined Rib. . 40. Leather Strip for Curved Fillet. When one or both of the adjoining surfaces to be filled in are of a curvature to which a straight fillet cannot readily be bent, a strip of leather of section shown by Fig. 40 is soaked in water to make it pliable, glued, and then pressed in with a short stick of wood turned with a rounded end ; or a strip of soft metal rolled to the required section is pressed in, and cemented with a solu- tion of shellac. Such sections are supplied by dealers in pattern-makers' requisites. Fig. 41. Fillet Worked Out of Flange. In some cases it is desirable to work fillets out of the solid, and one such instance is shown in Fig. 41. Here, the additional base given to the shallow flange is of great advantage in fastening the parts together, without adding 34 PRACTICAL PATTERN MAKING. greatly to the work assuming, of course, that the flange is curved in plan. If the work is built in segments, the bottom segment may be made wider, to allow for working the fillet. A cheaper expedient for curved work is to fill in the Fig. 42. Fig?. 42 ani 4:^. Strong Form of Feather-edged Fillet. space with a mixture of beeswax and resin. This cement is melted and brought to shape with a heated iron, having one end shaped a half-round. Occasionally beeswax alone is used, but generally it is too soft. Fig. 44. Weak Form of Feather- edged Fillet. Fig. 4. r >. Fillet for Core-box with Loose Ends. The strength of feather-edged filleting depends greatly upon the disposition of the grain of the wood. In Figs. 42 and 43, for instance, it is arranged in the most advan- tageous manner, whilst in Fig. 44 the shortness of the grain would render it so weak as to be useless in a JOIXTING-UP PATTERNS. 35 pattern, even if it could be worked successfully. In such cases it should invariably be let into the lower piece. In Fig. 45 is shown a combination of feather-edged and inserted filleting, used when one p#rt of the core-box or pattern is not permanently attached to the other. Sometimes, as in small brass fittings, the angles may best be worked out of the solid, as, for instance, in the Fig. 4G. Fig. 47. Figs. 46 and 47. Fillets Worked out of Solid. guide blocks in Figs. 46 and 47. If the pattern is formed of two pieces jointed in the plane A B (Fig. 47), the two may be taken apart, and c, being worked straight through, its shape is scribed upon D, and the small pockets in that piece are cut out with carving gouge and chisels. About half the thickness of the metal is usually suffi- cient for the radius of a fillet ; if it is too great, metal will be concentrated so much as to draw or become spongy. . 36 CHAPTER III. FINISHING PATTERNS. A PATTERN that has been brought to a curved shape by chisel and gouge must be glasspapered afterwards to re- move the marks of the tool ; in planed work it is best dis- pensed with. In ordinary work No. 2 paper, followed by No. l or No. 1, will be found most useful. All tool work should be done before glasspapering, or the part so treated will probably be soiled by handling before the other part is ready, and the tools will probably be dulled by particles of grit. Sharp edges should be rounded off, and, if not already done, angles filled in with curved fillets. A coat of varnish prevents a foundry pattern absorb- ing moisture from the damp moulding sand. The varnish is made by dissolving shellac in methylated spirit, and is applied with a camel-hair brush. When the first coat has dried, the surface will be found to be roughened by the raising of the grain of the wood. It must be rubbed down with a piece of used glasspaper, and another coat of varnish applied. After this, lightly rub down again and apply a third coat. Red-lead is sometimes put in the varnish to give more body to it, and to fill the pores of the wood more thoroughly. Whilst the pattern body is thus coloured yel- low or red by the varnish used, core prints and parts on which loose pieces are to be wired are rendered con- spicuous by varnish to which lampblack has been added. Further, to inform the moulder of the shape, the section should be hatched on the joint face on one half of the pattern with another coloured varnish. Patterns should be stamped with a number, and all loose parts should also have a similar number to show the pattern to which they belong, and in addition a distinguish- ing mark, to be repeated on the pattern near the position of the piece. A number of loose pieces belonging to one pattern may be kept together by threading on wire passed through small holes bored in the pieces. FINISHING PATTERNS. 37 Searing signifies the smoothing and hardening of the surfaces, or portions of the surfaces, of wooden patterns in order to render them more easy to draw, and better able to resist the action of moisture in moulding sand. It may be used with or without an after protective appli- cation of shellac varnish. Searing is used for rough work as being more rapid of accomplishment than the action cf cutting tools and of glasspaper, and it is adopted also in certain sections of good work to produce uniformity and precision of results which could not well be obtained in any other way. There is one application of searing which consists in going over large flat surfaces with a hot flat iron. Many years ago, the flat surfaces of large patterns were quite corn- Fig. 48. Iron for Searing Plain Surfaces, monly seared or scorched in order to smooth and harden their surfaces, and so assist their delivery from the sand. The old millwrights and the early pattern makers did not use shellac varnish to anything like the extent to which it is employed in the modern shops. It was re- served chiefly for the smaller patterns, and so much pains was not taken with patterns then as now. Standard pat- terns now in shops doing repetitive work are got up al- most regardless of cost. And it pays to do so. In a few of the very best shops the wood patterns are almost like cabinet work, and the iron ones as good as high-class fitters' work. The millwrights made their patterns more in the style of country carpentry, accurate enough for the pur- poses for which they were wanted, and mouldable, but with no attempt at finish, often not even glasspapered, and oS PRACTICAL PATTERN often without any provision for rapping and lifting. Those were the days when searing irons were employed. The irons used were of the shape shown in Fig. 48, differing only in dimensions. An average size for the flat portion was about 5 in. by 3 in. by 1 in. Some were shorter and narrower, some wider. They were brought to a low red heat in a clear fire, the face just rubbed over with a Fig. 50. Searing Holes for Cone-headed Screws. Fig-. 49. Searing Plain Bolt Holes. file, and then the surface of the pattern was seared with the broad face. A quick man could go over a reasonably large pattern at one or two heatings of the iron. It was just a light skinning, not a charring of the wood. It closed and smoothed the grain, obliterated plane marks, and gave a variegated brown and white appearance to the surface. Glasspapering was not necessary either before FINISHING PATTERNS. 39 or after, and the pattern so treated came from the sand freely. The method was only applicable to plain surfaces. The iron could not be worked round into corners or concave parts, but such parts would be glasspapered or left rough from the tools. Searing was very well adapted to large Fig. 51. Searingr Hole for Fig. 52. Searing Holes in Strainer Cheese-headed Screw. Core-box. plain patterns, saving the cost of varnishing or painting, and leaving for all practical purposes as good a surface. It did not protect the grain from the warping effects of moisture so well as paint or varnish, but that is seldom considered of much account in large plain patterns, which are, in fact, often broken up after use. The method, however, survives in another way. Holes for self-delivery are seared in this manner more rapidly 40 PEACTIGAL PATTERN MAKING. and quite as efficiently as by glasspapering. In thin cast- ings for which holes are cast for black bolts, or for cheese- head or cone-head screws, the holes are often made to deliver themselves in the sand instead of being cored out with prints. The holes which are cast in pipe strainers, though cored, are not inserted in print impressions. In these cases, therefore, the searing iron is used. Figs. 49 Fig. 53. Searing Hole of|ConvexJSection from Opposite Sides. to 52 illustrate the shapes of iron of this class. Fig. 49 shows one used for plain bolt holes. The amount of taper given to it is just sufficient to permit of free delivery in the moulded holes. The effect of a slight amount of taper in much black fitting work is of no consequence. In the holes for cone-headed screws (Fig. 50) the correct form is obtained much more truly and cleanly than by the use of cores, and with a far less expenditure of time FINISHING PATTERNS. 41 and trouble. Holes for cheese-headed screws (Fig. 51)' would be very troublesome to form accurately without the burning iron. When many holes have to be seared in a strainer core-box (Fig. 52) they can be done uniformly and quickly. Fig. 53 shows some work in which the hole has to be seared from opposite sides. These searing irons are made of wrought-iron or steel, and the burning ends are turned to correct form. If not overheated they will last for years. The handles are from 18 in. to 2 ft. long. When cutting holes which afterwards have to be seared, it is not necessary to observe such exactness of form as when they are finished by glasspapering and varnishing. The holes are bored small enough with a centre-bit ; that is sufficient when the form of the hole is, as in Fig. 49, just plain tapered. When it is of any of the forms shown by Figs. 50 to 53, it must be cut nearly to shape and dimensions with a gouge. The burning out of a parallel hole to form a considerable taper would char the timber too deeply ; the art of searing consists in just burning the mere surface to a brown or a brownish-black tint. The iron must not be too hot, and a contact of a second or two is sufficient. It is not necessary to do anything further previous to moulding, but the application of a coat or two of varnish to patterns or core-boxes for repetition use pre- vents the roughening up which results from frequent moulding 4-2 CHAPTER IV. CIRCULAR PATTERNS. IN describing a pattern to be used for making a mould, it will be well to begin with one of the simplest kind. Fig. 54 shows a knob to be turned up in the lathe ; it is not given as a model design, because a pattern made to the exact shape shown is almost sure to give trouble. The hollow part A has parallel sides, and lumps of sand will remain in the hollow, with the result that corresponding lumps will be found on the castings. Sometimes patterns are made of the shape indicated in Fig. 55 that is, with the hollow undercut and such a pattern will not leave the sand. The proper shape is given in Fig. 56 ; there it will Fig. 54. Knob Pattern Fip. 55. Undercut Fig. 56. Correct Shape with Chucking Piece. Knob Pattern. for Knob Pattern. be seen that all surfaces are sufficiently inclined to allow the pattern to be taken out of the mould without clogging the sand. When about to make such a pattern, first decide as to size, and then as to the quantity of castings likely to be required. If a great number, make the pattern in brass ; if only a few the usual method is to make it in boxwood. Beech is much used for large turned patterns, but for the present requirements is useless. The pattern may be turned in the lathe with ordinary turning tools, and smoothed with fine glasspaper, a good finish being got by taking a handful of clean box turnings CIRCULAR PATTERNS. 43 and holding these against the pattern whilst the lathe is run at a good speed A boxwood turned pattern finished in this way has a surface that is practically perfect, and will not need varnishing, etc. When making patterns of castings to be finished in the lathe, it must be decided beforehand how they are to be held for turning. The knob here shown will need something by which to hold it, and the plain projecting piece shown at the top of Fig. 54 should be left on for the purpose of chucking it. A screw can then be cut on the foot, or it can be drilled and tapped without removal from the lathe. From such a pattern as the one just described, it will be but a step to the making of spindles and more orna- mental work, but if these are of considerable length, as Fig. 57, they must be supported at both ends in turning. This is accomplished by leaving on the dotted portions, Fig. 57. Pillar with Chucking Pieces at Each End. and one end is held in a chuck on the lathe, while the other end is supported by the back-centre. Segments are chiefly used by the pattern-maker in the construction of circular patterns that are to be turned to shape on a face-plate, such as the rim of a wheel, a piston, ring, etc. Assuming that a casting has to be made, such as Figs. 58 and 59, first prepare a template of the required segment from thin stuff (Fig. 60). The space between the dotted lines and the outline is an allowance of J in. to J in. for turning the pattern and jointing the ends. The pattern for a turned casting has an extra | in. on each turned surface. The smallest patterns usually have four segments to the circle, whilst larger ones have six or eight ; only very large patterns have more. The number of segments that can be cut out of the width of a board is next ascertained, and the length of material required is computed. The thickness of wood for ordinary work is from f in. to in. For very slight and fragile work, the thickness is from i in. to | in. 44 PRACTICAL PATTERN MAKING. If the segments are small, say less than 12 in. long, the wood may be cut into convenient lengths for planing, and each piece faced perfectly flat. The template may then be used as a guide in marking out the segments on the face of the board. A band-saw, bow-saw, or compass- Fig. 58. Fig. 59. Figs. 58 and 59. Ring Casting. saw may be used for cutting out the segments, and a wooden face-plate is next mounted on the lathe as a foun- dation for building upon. To trim the ends radially, if a small allowance only has been left, hold the segment on a shooting-board and shoot the ends with a trying-plane. For making similar segments, the sawing-board (Fig. 61) will be an aid. On a rectangular piece of board D, about 1 in. thick, are screwed two blocks E and F, each having Fig. 6 . Template for Segments. a thickness slightly less than the depth of a tenon-saw blade. H is a template about f in. thick, one edge, butting against E, being planed parallel to a tangent of the circle of the segment where it is cut by the line B c, and recessed so that the segment A, when brought against it, has bearing CIRCULAR PATTERNS. 45 points at the ends only. In the line B c, and perpendicular to the base board, a tenon-saw cut is made through E and F to form a guide for the saw. Beneath the base at the front edge a strip is screwed, which, being gripped in the vice, keeps the appliance steady when in use. After one Fig. 61. Sawing-board. end of each segment has been sawn off true, another piece of wood, shown dotted at G, is fixed above the template to form a stop when the segments are reversed to have their other ends sawn off ; the radial line to which this is set should be marked on when the template is set out. In setting out the template H, the radius at the bearing places is that to which the segment is sawn. Generally, the ends can thus be left true enough to joint together, and Fig. 62. Segments Tightened with Dog. even when shooting is required only a small quantity has to be taken off. If the segments are large and the work heavy, each one of the first course may be screwed from the back of the face-plate, but in many cases it is sufficient to glue paper on 46 PRACTICAL PATTERN MAKING. the face-plate, and upon this the segments are glued. A pattern of considerable diameter and little depth may be held by a patch of glue at each end of a segment. The joints are drawn together with dogs, as shown in Fig. 62. When the work is finished a chisel is used as a wedge to split the paper and detach the work from the face plate. A quicker way is to nail all the first course on the plate with fine oval wire nails (well punched in), and when the work is finished wrench it off with a chisel as before. The nails are then pulled through the work and remain in the plate, or if found to remain in the work may afterwards be pulled through with pincers. The first course is faced flat in the lathe, and the outside and inside are turned down nearly to size. The next course is permanently fixed in place, each segment having Fig. G3. Building Pattern of Varying Section. its centre immediately over the joint between the segments in the course below it (see Fig. 62). These operations are repeated until the pattern is built up, after which it is turned to shape and finished. For a casting of varying section (Fig. 63), make each course of segments to a diameter obtained by setting out a full-size section. The courses and segments should be numbered. When the section varies slightly, several courses may be sawn of the same diameter. At a flange the segments should be so thick that the greater part (at least) of the adjoining fillet may be formed from them. When segments are to be built up on a wooden disc, as in the pattern shown at Fig. 64, a rebate is turned round the edge of the flat disc to form a bed for the segments. The segments are brought to a joint at A by means of spokeshave or compass-plane. CIRCULAR PATTERNS. 47 The joints between the courses are glued, and further secured by screws, nails, or pegs. For straightforward, substantial work screws are best, the heads being well let in to avoid the turning tools. For slighter work nails, well Fig. 64. Segments Built up on Difc. punched down, will answer, but, when the contour of the pattern is curved or tapered, it is best to use wooden pegs. Fig. 65 shows a steel plate for making the pegs circular after they have been split off. The central hole has a cutting edge slightly below the face of the plate to avoid accidental blows from the hammer. The holes at the side are for screws that fasten it to a block, with a central hole through which the pegs fall clear as they are knocked through one by one with a hammer. Allow all glued joints to dry before boring the holes into which the pegs are driven. A cheap circular pattern required quickly may be made of plaster. A circular pan with cover (Fig. 66), to fix on a gas fire and enclose a plumbers' ladle, may be taken as an example. The first thing required is a flat board Fig. f>5. Plate for Shaping Wooden Peg?. battened on the underside and made large enough to give a margin of, say, about 4 in. rovind the job to be strickled. Next procure a piece of square stuff and turn it down in the lathe at each end, as in Fig. 67, the length between the shoulders being equal to the depth 48 PRACTICAL PATTERN MAKING. inside the pattern required. Fix this in the centre of the board by means of the short peg, driving in two or three nails to hold it firm. The shape of the pan is next set out on a piece of pine about 1 in. thick, working from the centre line, as shown in Fig. 68. Set out the thickness of the metal required, draw a parallel line, then cut away to the inside line, also bore a hole in the strickle to allow it to revolve on the top peg. Everything is now (ready for striking up the core. The space between the strickle and the upright Fig. 66. Section of Circular Pan, with Cover. Fig. 67. Axle for Strickle. piece forming the core of the pan may be filled in with scrap wood, room being left, however, for a layer of plaster of Paris to finish. Superfine plaster should be used, well mixed, and all lumps should be thrown out. In laying on the plaster, keep working the strickle round on its centre, the result being a circular core of the shape of the inside of the pan. This must be allowed to set hard and afterwards var- nished. While this is drying, cut away the strickle to the second line, and varnish the baseboard where the strickle does not touch. Oil all the varnished parts and again lay on the plaster, keeping the strickle moving round all the time, the result being the outside shape of the pan. Use CIRCULAR PATTERNS'. the plaster fairly thin towards the finish so as to leave the pattern smooth. Allow it to set hard, and varnish it in place. When quite set, the shell can be easily removed from the core and the required pattern is complete. This is very cheap compared with making a similar pattern in wood. The cover for the pan is worked up in the same manner, core first and pattern afterwards. Fig. 69. Edge of Strickle. Fig. 68. Strickling Shell. Another convenient use for the strickle is found in striking up different forms of mouldings for use on fancy patterns both straight and circular. When a straight moulding is required, nail down a straight edge along which to run the strickle, and if a thin shell is required, strike up the core first as in the circular work, adding, of course, the varnish and oil. A strickle, after being cut to shape, should always be bevelled at the back, leaving the front edge about J in. thick, as shown in Fig. 69. 50 CHAPTEK V. MAKING COEE-BOXES. THE sand moulds used in metal casting are almost always constructed with parts made of dried sand, termed cores, unless the shape of the casting is a simple one. To form these cores, wooden moulds called core-boxes have to be made by the pattern maker. A simple cylindrical core is one which is constantly being required, and, if not of large size, is always made in a box such as is shown in Fig. 70. Assuming that a Fig. 70. Core-box for Plain Circular Core. core 3 in. diameter and 12 in. long is wanted, two pieces of wood, each measuring a little over 12 in. in length, about 6 in. or 7 in. wide, and 2 in. thick, are dowelled together face to face, the dowels being placed towards the edges of the wood. For a box of this size, dowels would be put in two opposite corners, as in Fig. 71, which is a view of one half of the box. The ends are then squared off, and the length is finished to the required size. On the back of each part, pieces of wood termed " backing " are glued and screwed, with the grain running at right angles to that of the core- MAKING COKE-BOXES. 51 box. The backing is generally a very necessary part of the core-box, in order that it may possess sufficient strength and permanence of form. The core maker raps the backing with a mallet to loosen the core in the box, and to save it as much as pos- sible from the effects of the blows, the backing should al- ways have the edges well chamfered off, and the holes Fig. 73. Template for Work ing Circular Core-boxes. Fig. 71. Half of Core- box, showing Dowels. Fig. 7 2. Core-box for Bend-pipe. through which the screws pass deeply countersunk. A 3-in. circle is now struck on one end of the box; and from each point of that diameter of the circle that inter- sects the joint of the box, gauge lines are marked on one half of the box. Another circle is struck on the other end, and the box is ready to be worked out. This is done by means of gouges and round-soled planes. If the core-box should be shaped as in Fig. 72, which PRACTICAL PATTERN shows a core-box for a bend-pipe, planes are not available, and a template or a set-square is necessary to ensure truth of shape. Fig. 73 shows the template, which is used by smearing the semicircular edge with red lead and oil, and trying in the box from time to time as the cutting out progresses. If a set-square is used, it is applied as in Fig. 74, the dotted lines showing varying positions of the square. When the two sides rest on the ed^jes A B, the rectangular corner of the set-square c will always occupy a point in the circle which has A B for a diameter. It is best to make a special set-square for this purpose, about i in. or T n ( . r in. thick, with a little steel plate inserted in a saw-cut (see Fig. 75) and riveted through. The thickne: :> of the square will then prevent the edges of the box being Fig. 74. Working Out Circular Core-box with Set-square. Fig. 7o. Fixing Steel Plate in Corner of Set-square. damaged, and the steel plate will resist the wearing action at the angle, which would otherwise soon render the square useless for this purpose. Fig. 75 is a sketch of the corner of the square. In making a core in the box shown in Fig. 70, the two parts would be clamped together, the box placed upright and sand rammed into the cylindrical space. When it is either impossible or awkward to ram the core from the end, as in Fig. 72, the ends are stopped by screwing on pieces of backing stuff, as shown. The two halves of the core are then rammed separately, and the halves of the box are brought together after a wash made of clay and water has been smeared on to fasten together the halves of the core. When an internal flange is required in a straight box of any considerable length, such as A (Fig. 76), it is usually MAKING CORE-BOXES. 53 best to cut through to the greater diameter, and then let in the flange (which is turned in halves) as shown. If, however, a large number of them were required somewhat close together, it would be best to cut through to the Fig. 76. Intemal Flange Fitted into Core-box. smaller diameter, and cut out to the larger diameter with gouges. Cores of the shape of Fig. 77 are called "chamber cores," and are frequently required. If the chambered part namely, that having the greater diameter is long, whilst the remaining part is short, a good way of making the box is to cut through to the large diameter, and then, Fi?. 77. Chamber Core. cutting away the ends, make up with blocks placed trans- versely, and cut these through to the small diameter. This is shown in Fig. 78. If the box is required for making a few cores only, it will then be sufficiently strong without backing. If the part having the smaller diameter be very short, a plain piece may be screwed on to the end and worked through, as shown in Fig. 79. 54 PRACTICAL PATTERN MAKING. Cores which are rectangular solids, or approximate to being so, are of a shape which is very much required. Sup- Fig:. 78. Core-box for Chamber Core. pose a small core, as Fig. 80, to be required, then the box is made as shown in Fig. 81, with one diagonal along the line of the joint. This ensures the box coming freely away from the sand after ramming. In making the core, the two parts of the box are held together, placed on a flat board, and scraped off level after ramming. Fig. 79. Core-box with End of Small Diameter. Such a method of construction as that shown in Fig. 8 1 is applicable only to core-boxes which are of the smallest MAKING CORE-BOXES. 55 size. For larger cores the construction shown in Fig. 82 is almost invariably used. The ends are housed into the sides, and, when the core is rammed, some of the screws are slackened so that it may be more easily removed from the box as at A. For large boxes, screwed pins and bow nuts are used instead of ordinary wood screws ; this is shown at the corner B. Bosses, ribs, or other projections with axes at right angles to either of the sides or ends may be fixed on, and when the fastenings of the box are removed the side or end may be drawn away without dis- turbing the sand. If bosses are required on the bottom Fig. Sl. ^U/" ^l^ rig. 80. Figs. 80 and 81. Rectangular Core and Core-box. of the core, the box is dowelled on to a bottom board upon which the boss or rib may be fastened. A boss may be formed on the top of the core by dowelling across it a narrow bridge-piece, upon the underside of which the boss is fixed. A boss inclined at an angle to one of the sides may be formed by making the boss loose, and withdrawing it after the sides are taken away; or a plug having a shoulder to ensure it being properly placed is passed through the box, and the boss formed upon the end inside the box. This plug is withdrawn from the core before the sides of the box are removed. The centre line of the hole through which it passes is, of course, at the same angle as the boss. 53 PRACTICAL PATTERN MAKING. Large round cores are generally formed without using a box at all but in special cases a box is required, and then it is built up as in Fig. 83. A number of lagging pieces are fitted into transverse pieces A, and end pieces B are fitted on after the shape of the box is worked out as at c. In most cases a half box is sufficient, the two half cores, after being made, being fastened together. Fig. 84 is another case in which a half box may bo Fig. 82. Built-up Box for Large Rectangular Core. used, but for Fig. 85 a whole box would have to be made, for the two halves of the core would overlap each other if placed face to face. Fig. 86 shows the shape of a core which can be made with a half box if provision is made for placing the branch on one half to the full lines, and on the other to the dotted lines. This is done by having two branch pieces cut out, and stopping one off when one half core is made, and the other part when the other half is made. In moulding flywheels, spur wheels, and large pulleys, MAKING CORE-BOXES. 57 core-boxes such as Fig. 87 are in general use. If the wheel has six arms, a segmental box embracing one-sixth of a circle is built up, and in this a pattern of one-sixth of the wheel is fitted. The sides are made to come apart and Fig. 83. Half Box for Large Circular Core. withdraw separately from the core, leaving the arm in the middle of the core to be withdrawn afterwards. If for a flywheel, the face is made by means independent of the core-box. If for a spur wheel, another segmental box is Fi Fig. 85. Figs. 84 and 85. Symmetrical and Unsymmetrical Cores. made for forming the teeth, and the cores made in it aro laid in a circle in the mould. Thus a nearly complete mould is formed by laying the cores on a flat bed of sand. 58 PRACTICAL PATTERN MAKING. The top is covered up either by making a ring of flat seg- mental cores, or by covering with a box of sand rammed up and scraped off to a flat surface. Fig. 86. Core for Bend-pipe Fig. 87. Core-box for Making with Branch. Flywheel. A complete pattern may, of course, be used instead of core-boxes, and in the case of small castings it is some- times better to do so, but core-boxes are almost always used for large castings for the sake of reducing the cost of pattern making. CHAPTER VI. CORING HOLES IN CASTINGS. IN very many cases the best method of coring a hole is obvious and simple enough ; but it is otherwise in a large number of instances. It is proposed to give in this chapter a few examples of this class of work. Take first one of the very simplest cases that can occur, a plain cylinder cover (shown in Figs 88 and 89). To core the centre hole A for the stuffing-box and piston-rod, a print Fig. 89. Figs. 88 and 89. Casting of Cylinder Cover. is put on the pattern on the side which goes downwards in the mould. This is shown on the pattern at A (Fig. 90), where the pattern is illustrated in the position in which it is withdrawn from the mould. Since the hole is shouldered, that is, not parallel throughout, a core-box must be made. This is illustrated in Figs. 91 and 92. The core made from this is dropped into the print impression A in the mould, and is thus centred and retained in its 60 PRACTICAL PATTERN MAKING. correct position. The mould, with its core in place, is shown in section in Fig. 93. This is a very common illustration of the simplest kind of coring. Almost all holes which pass vertically through castings are formed by the insertion of cores thus set in print impressions in the lower portion of the mould. There are a few special exceptions, as in the case of work for which the cores are so large that they are set in place by measurement alone, since they do not need assistance from the impressions of prints. All prints which are used for vertical cores are tapered, or coned smaller in a direction away from the pattern face. This is shown in Fig. 90. It is done to prevent the print from tearing up the sand, which a parallel print would almost certainly do on withdrawal. The reason why a larger amount of taper is given to a print than to its Fig. 9i '. Cylinder Cover Pattern. pattern is that a moulder always desires the maximum taper which is permissible in any case. He cannot have just what he likes in a pattern, but he can in prints, and so he gets it. It is better, too, that a core print should have plenty of taper because when a print tears up the mould, the latter has to be made good again ; and if badly broken, it probably would not be mended quite accurately, and then the core would be set out of truth and the hole in the casting be correspondingly out of truth. It may be noted, further, that while the print is tapered there is no taper in the core-box (Figs. 91 and 92) to correspond ; consequently, taper has to be filed or rubbed on the core to make it enter and fit the print impression exactly. When a few castings only are wanted, it is not usual to put the print taper in the core-box ; but if many (say twenty and upwards) are required the taper should be formed in the box to correspond with that given to the print. It saves the moulder's time, and reduces the CORING HOLES IN CASTINGS. 61 risk of the cores being set out of the vertical, due to more being filed off one portion of the sides of the core than off others. There is yet another point of importance. One print only is shown on this pattern (that on the bottom), and it is sufficient in the example given. But suppose the length, or height, of the core were double or treble what it is, then one print alone could not be trusted to hold safely the core upright. In such a case a second, or steady, print is put on the top face to make a hole for the top end of the core. This is shown dotted at B (Fig. 90). Many cases occur in which top prints are absolutely necessary ; but, obviously, lengths and diameters are re- Fig. 91. Fig. 92. Fiyrs. 91 and 92. Core-box for Cylinder Cover. Fig. 93. Mould for Cylinder Cover. Intive. So that if a core were 4 in. diameter and 12 in. high, it could be set safely in a bottom print alone ; but if it were 1 in. in diameter and 12 in. high, a top print would be required. Also, a long vertical core may be held by a bottom print alone if there is a good chance of centering it by measurement right up to the top ; otherwise, a re- latively short core may require a top print. For example, in Fig. 93 measurement can be taken in the mould from the edge of the core to the edge of the mould, the radius A A being easily taken. Then the question of the securing of the core in the top simply means the thrusting of the core well into its print impression, and the application of the pressure of the cope on the top of the core. Many cases, however, arise in which a large portion of the mould comes up into the top and the core has to pass up into it, and measurement cannot be taken at the top. Then G2 PRACTICAL PATTERN MAKING. a top print is desirable to guide the core correctly, be- cause the moulder cannot see and measure it. In some later examples attention will again be drawn to this im- portant point. Cases arise in which top prints cannot conveniently be used. Then the difficulty is often got over by making the bottom print double, or even treble, the usual length, so that it shall form an efficient stay, as well as a guide to the core. The lengths of these prints and the amount of taper to be given to them vary within wide limits. For bottom prints up to 2i in. or 3 in. diameter, the length is usually made about equal to the diameter; over these diameters the length diminishes. But, after all, the length depends in the main on the length of core which the print is re- quired to steady ; so that for coring through thin plates of metal, prints of 2 in. diameter need not be more than i in. or | in. long, or thick. For coring through a con- siderable depth without top prints, a 2 in. print would sometimes be made 3 in. or 4 in. long. For coring holes at a bevel, prints are made longer than for similar cores set vertically. As regards taper, an average print will be tapered about ^ in. in its length few less, the larger ones more. Both length and taper are therefore matters to be decided upon according to the requirements of each individual job. Another matter, very obvious apparently, relates to the length to which core-boxes must he made or cores cut off. This length must always include the length of core re- quired in the casting, plus the length of print on the pattern. That is obvious on comparing Figs. 88 and 93. When holes have to be cored in horizontal positions in the mould, either two prints or one may be used, but taper is not required in the portion of the print that forms the impression for the core. In the case of what are called "pocket" or "drop" prints, the portions above the part which corresponds with the core are tapered. Two prints are employed when the mould is wide, and only one when it is narrow. Taking a familiar object, Figs. 94 and 95 illustrate a plain steam cylinder casting in longitudinal and in trans- verse sections. The central bore A has to be cored with a CORING BOLKS CASTINGS. 63 horizontal core laid in two parallel print impressions. The passages c c B have. to be formed with cores laid in bottom tapered print impressions ; B will be supported at the other end c (Fig. 95) in a parallel print impression ; c c are supported at one end only by prints. At the opposite ends they abut against the main core A. In some exceptional cases core print impressions for c are cut in A, so fulfilling the purpose of top prints ; but jn general work it is more convenient to dispense with their assistance. Figs. 96 and 97 illustrate the pattern of this cylinder in the position in which it would lie in the mould. The c B c Fi of the worm and the pitch Q, as the two sides of a right-angled triangle, and the hypotenuse E will give the angle of the wheel teeth. It is necessary to get this angle, as a guide by which to glue on the blocks for the teeth, even though the latter are shaped with the worm as a template. If the teeth are marked off and shaped directly without the aid of the worm as a template, then it is by this angle that the teeth are marked round at definite distances out of the perpendicular on the joint face A A, and on the dia- meters B B. The total amount of departure of the teeth from the, perpendicular on the extreme diameters B B is equal to F, obtained by the angle of the worm wheel teeth. The method of lining out being now clear, the making of the pattern involves a neat bit of work. Such patterns must always be glued up in segments, and always parted along the central plane A A. Readers have already been told the methods adopted in building up segmental work to ensure permanence of form. Figs. 185 and 186 show one- half the pattern built up roughly, that is, not turned to shape, the method being suitable for a wheel of about 2 ft. diameter, or more. Far smaller wheels fewer seg- ments may be used, and the plated portion can be solid instead of being formed in two thicknesses as shown. The illustration explains itself. There are two methods of jointing the halves, shown in Figs. 187 and 188. In the first the plate is built in one, either with or without segments, and the top part of the pattern is jointed as a ring to it. This is not so durable a method as the one shown in Fig. 188, in which each half ring is glued to half the plate thickness. The loose un- stayed ring in Fig. 187 is apt to go out of truth in time ; but in Fig. 188 both rings are supported alike with a half thickness of plate. After the rings are glued up, the curve of the rim upon which the teeth are to bed is turned by template A (Fig. 189) made from the drawing. This curve, and the joint WORM WHEEL PATTERN, 105 faces of the two halves, are the parts to be turned first, because they are the most important. Afterwards the halves can be re-chucked by the central stud B and corresponding stud hole, and the edges, the inner rim curves, and the outer faces of the rim turned. In addition to the central stud, it is necessary to insert a dowel Fig. 187. Fig. 188, Fig. 189. Figs. 187 and 188. Jointing Worm Wheel Pattern. Fig. 189. Turning Outside of Wheel Rim by Template. between the two halves of the pattern to preserve the two halves always in the same position in relation to each other, so that the edges of the teeth shall always coincide precisely. Before ire-chucking, the blocks for the teeth ought to be fitted and glued on, otherwise time will be wasted. The half-lengths of the teeth, with turning allowances, are fitted 10( PRACTICAL PATTERN MAKING. with a chisel at approximate angles to the turned seatings, which are chalked to show points of contact. They will have the appearance seen in Fig. 190. They are then faced and turned to the form in Fig. 191 with template A, after which the re-chucking before alluded to will follow Fig. 190. Tooth Block Glned on Wheel Rim. Fig. 191. Turning Tooth Points by Template. Fig. 192. Turning Inside'of Wheel Rim by Template. (Fig. 192). Then the face B will be skimmed over to tho required thickness, and upon it a template A will be set for checking the turning of the inside of the rim and its edges and the ends of the teeth. This is shown clearly by the illustrations, so that more detailed explanation is not required. The centres of the teeth are now to be pitched WOEM WHEEL PATTERN. 107 the joint face A A (Fig. 184) on one half of the pattern. To obtain the forms of the teeth, see Fig. 193 and 194. For all involute teeth there is a base circle A (Fig. 193), as well as the pitch circle B, which is used for convenience. The base circles of a pair of wheels coincide approximately with the Fig. H>3. Forms of Teeth on Worm and Wheel. roots and the points of the teeth c. A line drawn tangent to both base circles is the pitch circle or path of con- tact of the teeth. In a worm tooth, as in a rack, the tooth flanks are at right angles with the tangent line (Fig. 193). In the wheel tooth the movement of the tangent line on the base line A gives the curve for the flanks. This is done in practice by laying a slip of wood carrying a needle-point against a template, cut to the radius of the base line, and moving the slip around it, the needle-point then marking the tooth curve (Fig. 194). The Fig. 194. Template for Marking Tooth Curves. angle of obliquity usually adopted for rack teeth is 75 with the line of centres. The teeth should all be marked out in the joint face of one half the pattern, and cut in a little way with the chisel. The teeth on the other half of the pattern can 108 PRACTICAL PATTERN MAKING. be marked from them, and cut or set in. That is all the marking out that is really necessary. The two half patterns are screwed together, chalking the outlines set in, to prevent risk of cutting into the tooth forms in the sub- sequent work. Take the worm and place it truly between centres in the lathe. Take the wheel, and mount it on a pin or pivot fixed in a socket-rest in such a way that its central plane A A (Fig. 184) will coincide with the central axis of the worm, the wheel being perfectly horizontal, and so arranged that it will move round on the pin with freedom, and without play. The worm and wheel pattern will then occupy precisely the same relations which the castings will occupy when working. The only difference Fig. 19.-J. Cutting Wheel Teeth. will be that the T- rest socket must be set and guided by a couple of parallel strips screwed across the lathe-bed, so that it can be slid to and fro, putting the wheel into and out of gear with the worm. Fig. 195 shows a suitable arrangement in plan, A A being the lathe bearers, B B parallel strips, and c the T-rest socket. It is now easy to see that the wheel teeth can be cut carefully and tested until they make a perfect gear with the worm. When cutting the teeth, the T-rest socket is drawn back. To ascertain the amount of contact and accu- racy attained, it is thrust forward, and the worm is re- volved by hand, carrying the \vheel round a portion of a circle, and leaving marks of contact on its tooth flanks, the worm being smeared with red lead and oil for the purpose. If the rig-up is steady and due care is taken that the WORM WHEEL PATTERN. 109 tooth forms set in on the middle plane are not cut below, there is no need to mark the tooth forms on the outer faces B B (Fig. 184). Still, it is safer on the whole to do so. After working, therefore, three or four teeth carefully, the forms on the outer faces B B will be developed differing, of course, from those on the joint face A A (Fig. 184) and their widths and the location of the radii of their flanks can then be taken and set out round the remainder of the wheel. The time of marking out is not wholly lost, be- cause, after marking, all the teeth can be cut in by the lines nearly to shape without any trial in the worm until the final corrections are necessary. If these directions are followed carefully, the result will be a more perfect gear than can possibly be attained Fig. 190. Cross Section of Finished Worm. Wheel Pattern. by any method of marking out direct from a drawing of the tooth forms. The conditions being precisely those which exist in actual gear, the rest is a matter of care on the part of the workman. Fig. 196 shows the wheel complete in cross section, with teeth, central stud, dowel, bosses, and prints in place. The bosses may be screwed or studded on. The latter is more favourable for subsequent alterations in bores, if such are likely to be required. Fig. 196 shows the central web built up, each half in two thicknesses, as in Figs. 185 and 186 ; but some of the illustrations show one thickness only of solid stuff. In adopting the latter method, how- ever, it is always best to make open joints, if a wheel is over 10 in. or 12 in. in diameter. The segments will hold together the strips which form the plate. 110 CHAPTER X. LATHE-BED PATTERNS. THIS chapter will describe first the pattern for a lathe- bed (Figs. 197 and 198), a plain bed for a hand-turning lathe without slide-rest. Fig. 199 is a cross section. Dimensions are not given, and are not necessary, but the figures are drawn proportionately for any lathe of from 3-in. to 7-in. or 8-in. centre, and the method here described for constructing the pattern will be correct for any lathe bed of that type. Its parts are, sides A, sliding ways B, cross-bars c, mouldings or fillets D, and feet or flanges E. There are two ways in which the pattern for such a bed may be made first, like its casting with some very slight x : B B v----^-f--r- r B--- ----:::: -------- -----4--" : 3 c E| ; Oc IE c[ H a Fig. 197. B E Fig. J99. ' 1 v i : ii o i Fig. 198. Figs. 197 to 199. Lathe-bed Casting. differences ; or it may be made so that only the outer faces correspond with the form of the casting, and the in- terior portions are represented by core-prints only, core- boxes being required in this case for coring out. The first method is much preferable in the case of the bed in question. In moulding any lathe-bed, it must be remembered that the sliding faces must be cast downwards with the object of securing clean metal there. So this settles the way in which the pattern shall be tapered and which portions are to be kept loose. o 111 112 PRACTICAL PATTERN MAKING. Figs. 200 and 201 show the pattern of the bed in eleva- tion and cross section, just as it is laid down during the operation of moulding. It is well when making a pattern always to picture it mentally just as it stands when being moulded, and the details then seem to work out naturally. The sides A are tapered downwards, say from J-y in. to 3^- in. in beds of from 4 in. to 6 in. deep, and an much as in. in deeper beds, say from 7 in. to 8 in. deep ; that is, they are thinner by that amount at the bottom than at the top edges, as shown in the cross section to the left hand. The cross-bars c are tapered similarly. When putting together the sides and cross-bars ; of such a pattern as this two difficulties are likely to be encountered. One is that of getting the pattern quite straight lengthwise, the other that of keeping it out of winding. The first is due to the stuff being planed crooked, the second to its being planed winding, or to the ends of the cross-bars not being planed to precisely the same bevels, and also to the cross-bars not being inserted precisely alike, as regards position up or down. If the pattern is winding when finished there is no means of getting the winding out afterwards. It must be pulled apart and corrected, or the casting will be winding. To prevent such inaccuracy, the sides must be planed truly first, straight lengthwise, and free from winding. In thin stuff like this, which will not be more than \ in. or f in. thick in any case, it is not easily done. Jack plane the stuff all over first, removing the outside and exposing the grain to the air ; let the job stand for a day or two and then finish with the trying plane, using a straight-edge for checking the truth lengthwise, and winding strips for the twist or winding of the stuff. If the face of the work is true, the strips when looked across will show a perfectly level plane, no portion of the edges standing any higher than the rest. The cross-bars c should be planed preferably with the grain running across as shown, then any shrinkage which may occur will not affect the width of the lathe-bed as it would if the grain ran perpendicularly ; also the pattern is stiffer than it would be if the grain ran perpendicularly. To ensure symmetry and prevent risk of winding, the ends of the bars should be planed tapered from a centre line, LATHE-BED PATTERNS. 113 as in Fig. 202, the dimensions F. being equal, and G also equal, the difference between F and G being exactly the same as that due to the taper on the inner faces of the sides A. Then having one cross-bar planed correctly, mark the others from it with a scriber, and plane accurately to the scribed lines. Then if the cross-bars are all screwed between the sides with their edges o exactly level with the edges of the sides A, there will be no risk of winding occurring. The sides are screwed to the cross-bars, and need not be removed during moulding. The top strips B, however, must not be fastened, yet they have to be secured in place during ramming up of the pattern. This is done by the use of dowels F (Figs. 200 and* 201), which retain the strips in place, but which permit of the taking away of the main body of the pattern from the strips after the mould- ing is completed. The mould is jointed along the plane G and then, after the removal of that portion of the mould which contains the main body of the bed, the strips B are left exposed in the bottom part to be withdrawn from the sand separately. On these strips an allowance for planing the casting has to be made. The allowance need not exceed J in. on each planed face unless the bed is exceptionally long, or unless the foundry where it is made turns out rough castings, and then ^ in. will not be too much. The faces to be planed are the top H (Fig. 200) for the poppet, etc., to slide upon ; the inner face J for the headstock and poppet to fit between ; and the outer edge K for good appearance. These strips must be dowelled accurately upon the sides. If they do not lie parallel and in winding with one another some of the planing allowances will have to be used in getting the casting t rue, and if the inaccuracy amounts to much it may happen that the casting will not hold up to desired dimensions. The strips being dowelled on very narrow edges will not lie very steadily on them, but that will not matter ; if put on truly, they will be all right and steady when laid upon the levelled bed of sand upon which the pattern will be moulded. The filleting D is prepared in separate strips ; it is screwed, and it may also be glued, along the sides. These Ill PRACTICAL PATTERN MAKING. ^ < (ti m * 4 - U< LATHE. BED PATTERNS. 115 strips act as material stiffeners to the pattern, as they also do to the casting. The feet E by which the bed is bolted to its standards, may either be screwed on or dowelled on, it matters little which. They are shouldered to fit within the sides A. Their faces may be planed all over, or narrow strips may be used as shown. Fig 203 shows the under side of one of these pattern feet. The strips will save some labour if the lathe builder prefers to chip instead of planing. It will facilitate the moulder's work if the pattern is well glasspapered across the grain, along the width of the stuff, and on the sides and ribs, using a rubber for the purpose. This will remove the plane marks and make a nice smooth surface favourable to delivery. When the pattern delivers freely from the mould, there is tolerable certainty that the casting will be just like the pattern ; but when the moulder has to mend up, elements of uncertainty and inaccuracy come in. Two applications of clear shellac varnish will suffice, each being rubbed down when dry with fine glasspaper. In reference to shrinkage allowances, these may almost be neglected in small beds. If the bed is 4 ft. long the difference in length due to shrinkage will be about | in. ; if the bed is 5 in. wide over the strips the shrinkage in breadth will only be in theory a full -^ in., and will prob- ably amount to nothing at all, because the moulder will rap the pattern to that extent. The making of a pattern for a gap lathe-bed is different from that just described for a plain bed which was made to deliver without cores. The one shown by Figs. 204 to 206 will be better if cored out, because the cutting out of the gap would render a pattern for self-delivery very flimsy. That such is the case is evident from a glance at Figs. 204 and 205, where it is seen that the cutting out of the gap would break the continuity of the wood in the side webs A, and there is nothing to reinforce their rigidity. The pattern would therefore twist, especially in small beds of light scantlings, say with sides A only in. or f in. thick. The pattern is also rather too deep at the gap for easy delivery. Likewise, in many instances, as in Figs. 204 to 206, the bottom of the gap is bridged over with metal, and that necessitates an awkward lift of sand in 116 PRACTICAL PATTERN MAKING. LATHE-8ED PATTERNS. 117 the top N above the bridged part that is, " top " as the pattern moulds. Then there are deep lifts at o adjacent, which would require a good deal of taper in the pattern there. Another good reason for coring such beds in a machine* maker's shop is that, as lathe-beds for poppets of similar centres often have to be supplied of different lengths to suit customers, it is easier to alter the length of a solid pattern provided with core-prints and core-boxes, than one made to deliver itself without coring. There is little more difficulty in this job than in the last, but there is more work involved. The type of bed and proportions shown in the illustrations would be suit- able for a lathe of from 3^ in. to 7 in. centre. In Figs. 204 to 206 A shows the sides ; B, the bearers ; c, the cross-bars ; D, the gap ; E, the feet ; F, facings for the brackets for the leading screw ; G H, fillets. The main body of the pattern is made, not from solid stuff, but by "boxing up," by which the pattern is pre- vented from warping to any important extent. Boxing up occupies more time than cutting from solid stuff, but it saves timber, and produces a better job. The method oi boxing up is shown in Figs. 207 to 211, the pattern being drawn in those figures in the position which it occupies during moulding that is, upside down. Fig. 207 is a cross section through the main body of the pattern, showing the method of building up ; Fig. 208 is a longi- tudinal elevation ; Figs. 209 its plan, looking down on the bearers ; Fig. 210, the plan of its under side ; Fig. 211, a longitudinal section to show the cross-bars. The rectangular section is built up of two vertical sides A, A, running the entire depth (Figs. 207 to 209), in- cluding the thickness due to the undercut bearers B, B, plus in. for planing, and cut to the vertical outline of the bed (Fig. 208). Between these and the top and bottom por- tions c, D, which complete the rectangle, cross-bars E are fastened by nailing or screwing. At the curved portions F (Figs. 210 and 211), blocking is inserted, sufficiently thick to permit of the cutting out of the curves. The sides A, A, and the ends of the pattern are tapered, the amount vary- ing with the depth of bed say, from 3 \ in. to ^ in. on each. If the gap has a solid bottom, as in Figs. 204 and 118 PRACTICAL PATTERN MAKING. i LATHE-BED PATTERNS. 119 205, it may be either cored out or cut out in the pattern. The work will be lessened and the pattern strengthened by coring it out. If the gap goes right through that is, without a solid bottom. it will be cored out. It is here assumed that it will be cored out. On the outer faces of the pattern, those portions of the bearer B with the strips which stand beyond the faces, will be skewered on (Figs. 207, 208, 209, and 210), or else fitted with easy-fitting dovetails (Fig. 212). The skewers are just as good as dovetails, and do not occupy so much time in fitting. Dovetails are neater, and if well fitted are very good. They are adopted in good work to prevent risk of the loose pieces becoming shifted out of place in the mould. Note that extra allowances for planing the castings will have to be made all over the sur- faces of these bearers ; from J in. to ^ in. is usually given. For coring out the interior, narrow prints G (Figs. Fig. 212 Fitting Baarers with Dovetails. 207, 208, and 209) are nailed or screwed along the centre of the pattern. They will be of the same width as the tenons on the under side of the heads, minus the planing allowances between the bearers. Thus, if the space be- tween the bearers is 2 in. in the finished casting, the print G will be If in. wide. From \ in. to f in. thick will be suit- able for these prints. H (Figs. 208 and 209) is the print for the gap-core. It is made of the same width over as the sides A, A (Figs. 204 and 205). This leaves the fillets K around the gap standing beyond the print. If the print comes out to the faces of the fillets, the core could not.be got in unless the sides of the mould were taken away. At I (Figs. 208 and 210) is shown the print for coring out the metal underneath the gap. The fillets J (Figs. 207, 208, and 210), shown at G in Figs. 204 and 205, go round the lower edges of the ribs A, stiffening them, and will be fastened on permanently with nails or screws. The method of their fitting is indicated by the timber shading. The fillet K in Fig. 208, which runs 120 PRACTICAL PATTERN MAKING. round the gap, corresponding with H in Figs. 204 and 205, is skewered on loosely. If these fillets were .fastened per- FJ>. 213. Fig. 214. Figs. 213 and 214. Core-box for Taking out Portion of Gap Lathe-bed. manently they would prevent the withdrawal of the pat- tern from the mould. Fig. 2 1C. Fig. 217. Figs. 215 to 217. Core-box for Taking out Portion of Gap Lathe-bed. The feet E (Figs. 204 to 206), which receive the stand- ards, are fitted differently from those illustrated in Fig. 201, p. 111. In the present case part of their thickness, LATHE-BED PATTERNS. 121 L L (Figs. 208 and 210), is nailed on the pattern. The re- mainder, or supplementary portion, which comes within the bed, seen dotted in Figs. 204 and 205, will go in the core-boxes. The facings F (Figs. 204 to 206) for the brackets which carry the leading screw are nailed on per- manently at M (Figs. 208 and 210). These complete the pattern for a gap lathe-bed ; but the core-boxes have now to be made. It is obvious that the cross-section inside of the core- boxes must be the same as that of the inside of the Fi ? . 218. Fig. 21 9. Figs. 218 and 219. Core-box for Taking out Portion of Gap Lathe-bed. bed casting, and that their outlines and dimensions length- wise must correspond with the outlines of the bed, and also that of certain dimensions measured lengthwise. These core-boxes are shown in Figs. 213 to 223, with dimension reference letters corresponding with similar lettering on the casting (Figs. 204 to 206) and pattern (Figs. 207 to 210). They are drawn in the positions in which the cores are rammed and placed in the mould that is, upside down. Figs. 213 and 214 show the core-box for coring out the portion p of the bed (Figs. 204 to 206) ; Figs. 215 to 217 122 PRACTICAL PATTERN MAKING. that for coring out Q ; Figs. 218 and 219, that for K ; Figs. 220 and 221, for the gap D ; Figs. 222 and 223, for the recess N. A cross-section of one main bed-box is shown at the left-hand of Figs. 215 to 217. That is also correct for Figs. 218 and 219, and the lower portion of it also for Figs. 213 and 214. Taking the sectional dimensions of the main boxes first : the .distances s (Figs. 213 to 219) correspond with the dis- tance s between the ribs A (Figs. 204 to 206), the distance T with the distance w between the bearers B, B in Figs. 204 to 206, minus the planing allowances, the actual distance : Fig:. 220. 1 and the guides E, and these would have to be skewered ori. The HEADSTOCK AND POPPET PATTERNS, 131 objection. to this pattern is the awkward down-jointing and lifting where the barrel is united to the vertical webs B. Another way is to make the barrel loose from the rest of the pattern, the pattern then moulding as shown at Figs. 240 and 241, in which figures the barrel is shown Fig. 240. Fig. 241. Figs. 240 and 241. Moulding Barrel for Lathe Poppet, Fig. 242. Barrel for Lathe Poppet, with Dowels and Hollows. away from the uprights, in order to indicate h'ow the two portions of the pattern are fitted and dowelled. Of course, in that case the small fillet seen in Fig. 237, where the vertical ribs B meet the barrel, must not be attached to the verticals, or they would prevent the withdrawal of the pattern from the sand. If introduced in the pattern at all they must be fitted round the barrel as shown in Fig. 242. They may be let in grooves as shown, or fitted round with a gouge, and glued, or flexible hollows may be fitted round. But it is not necessary to fit small hollows like these to the smaller class of patterns, because the moulder will sleek the angles if told to do so. For Fig. 243. Turning Poppet Barrel. standard repetition work they should, however, be aiways inserted. This is a very good and common way of making these patterns, and it ensures sound metal about the barrel, where it is most wanted. It is the method illustrated in Figs. 237 to 239. 132 PRACTICAL PATTERN MAKING. Another method equally good is to joint the pattern along the central plane F F (Fig. 238). Then no part is left loose, and everything is in favour of easy moulding. The foot A will be prepared first in two pieces, jointed and dowelled along the plane F F, and the uprights B B will be either rebated into it, as shown, or made to abut simply, then glued and screwed. The hollows G are also glued in. The barrel is turned with its prints H, the prints being made parallel. The barrel is in halves, and is jointed and dowelled and secured for turning not turned first and Fig. 240. Figs. 242 to 246. Well-designed Lathe Poppet Pattern. sawn through afterwards. In a small piece of work like this, clips need not be used for securing the two halves during turning ; instead, common wood screws are inserted in the roughly-prepared stuff a little way beyond the ends of the prints, as illustrated in Fig. 243, which shows the turned barrel, with its prints, leaving only the ends into which the screws are driven to be sawn off. The barrel is fitted to the uprights B either by the cutting-out of the latter to fit the barrel, similarly to the method shown at Figs. 240 and 241 ; or the ends of the uprights may be left straight, and grooves cut across the barrel to receive them. In either case the uprights are glued to the barrel AND POPPET PATTERNS. 133 Hollows like those shown may be glued in, strips of leather being as good as anything. The boss J may be fitted round the barrel in halves, and worked to shape by hand. The nailing on of the boss D and the guides E completes the pattern. The poppet shown in Figs. 244 to 246 is one of the nsatest and stiffest in use for small lathes. It must be moulded on its side, and may be unjointed ; but it is better to joint it along the plane D, as shown, because the outline Fig. 249. Figs. 247 to 249. Plain Lathe Poppet Pattern. can then be marked off in the joint of the pattern. The barrel may be worked by hand solid with the body, in which case the beading should be turned separately, and nailed on. Or the barrel may be turned and the body fitted to it, as shown, either by fitting it to the curvature, or by leaving the top part of the body flat and cutting out a portion across the barrel to receive it. The sec- tion across the centre of the body E is rectangular, with corners well rounded. The shape of the sides in Fig. 245 will be worked through by the aid of a template, and the 134 PRACTICAL PATTERN MAKLVG. angles rounded into the curved ends, which are marked from the joint faces. The guide-piece F is nailed on the bottom, completing the pattern. The timber graining shows the best disposition of the grain. A cross section at E E is shown below Fig. 245. Fig. 247 to 249 illustrate a plain poppet, easily made and readily fitted up. The pattern must be moulded upon its side, and should be jointed in the plane D as shown. The foot A is made in two pieces, less than the full width Fig. 250. Half of Lathe Poppet Pattern. by the thickness of the vertical web B, which is made in two thicknesses and is glued upon the feet. At the upper part, the half-webs are recessed a little way into the turned barrel, and the vertical ribs c are fitted between the foot, the web, and the barrel. Fig. 250 shows one half of the pattern, open on the joint faces, to assist in illustrating the union of the different parts, which, by a comparison with the other figures, will render everything clear without further explanation ; E indicates the boss which provides metal over the hold-down bolt. 135 CHAPTER XII. SLIDE-REST PATTERNS. THE illustrations accompanying this chapter represent the pattern work for an ordinary type of lathe slide-rest, begin- ning with the saddle and proceeding upwards. The cast- ings are not shown separately, but in the case of cored portions the forms of the cores, as they would appear in the castings, are indicated by means of dotted lines. This is mentioned to avoid confusion, for these dotted lines have no meaning in the patterns themselves which the figures represent. The saddle pattern is shown in Figs. 251 to 255. Fig. 251 is a plan view as the casting stands on the lathe ; Fig. 252 is an underneath plan showing the pattern as it lies in the mould ; Fig. 253 an end view at the front ; Fig. 254 an end view at the rear ; and Fig. 255 a side view from next the headstock. A saddle pattern of large area should be framed to- gether in three pieces, with half lap joints. Small saddles of from 12 in. to 15 in. in length can be cut from solid stuff, and the core prints will serve to keep the main plate true. The most suitable disposition of the grain for this mode of construction is shown in Figs. 251 to 255. In Figs. 253, 254, and 255 the thickness of the main piece is seen, with various fittings on both sides, while the plan views of these pieces are shown by Figs. 251 and 252. On the top face there are prints, and on the bottom face (Fig. 252) are broad facing pieces, which are planed to slide on the top of the bed, strips for the guiding edges, a bracket for the back shaft, and blocks for the attachment of the apron. In these figures, A is the print for coring out the recess for the cross traverse or surfacing screw. The core-box is shown in Figs. 256 and 257. All the patterns and core- boxes here illustrated are to an exact and uniform scale, so that comparisons between the corresponding dimensions of prints and boxes can be easily made, while the dotted 136 PRACTICAL PATTERN MAKING. Fig. 251. Plan of Slide-rest Saddle Pattern. SLIDE -REST PATTERNS. 137 Fig. 252. Underneath Plan of Slide-rest Saddle Pattern. 138 Pit AC TIC AL PATTERN MAKING. lines before mentioned in the figures which indicate the out- lines of the cored castings will further render the relations of core-boxes to patterns and to castings clear. The longitudinal and sectional forms of the core made from the box (Figs. 256 and 257) are indicated in Figs. 251, 253, and 254. The box in Figs. 256 and 257 is framed together with grooved ends, and is laid upon a bottom Fig. 234. Fig*. 253 and 254. Front and Back End Views of Slide-rest Saddle Pattern; board. The sides of the box are vertical in the print thick- ness, and bevelled below (compare with Figs. 253 and 254), to form the edges by which the cross traverse slide of the rest is guided. The semicircular recess in which the sur- facing screw lies, and the flat recess in front to receive the nut, are cut in the bottom board of the box. Of course, the box framing is not fastened to the bottom board in any way, because that would prevent delivery of the core. It is simply retained truly in relation to the board by SLIDE- ItEST PATTERNS. 139 Fijr. 257. 140 PRACTICAL PATTERN Fig. 258 and 259. Core-box for Sliding Pinion Spindle. Figs. 260 to 262. Surfacing Slide Pattern. Figs. 263 and 264. Ring Ccrj- box for Surfacing Slide. SLIDE-REST PATTERNS. Ul means of the pieces A nailed on the board, or by means of dowels, the method being merely a matter of choice. In Figs. 251 to 255 B and c show prints which core out the hole shown dotted in Fig. 251, for the spindle which makes the connection between the back shaft gear and the rack and pinion sliding movement at the front. The enlarge- ment of the hole next the print B is for the reception of the sleeve pinion, which renders the sliding movement auto- matic. It is not necessary to make the prints B, c of the drop or pocket form ; round prints will answer as well. In this case B will be nailed on, and the moulder will joint down to its centre ; c will be nailed on its boss, but both together will be held with loose brads as shown, to be drawn backwards into the mould. The print B is twice the length of c. The moulder will thrust the core endwise into the impression of c, leaving then at the other end a bear- ing surface in B equal to half the length of B. A core-box must be made for this in halves, dowelled together. It is shown in plan by Fig. 258, and in end view by Fig. 259, one half having been removed to expose the hole. In the part A the core cuts through the saddle, corresponding with the portion K left clear of facings in Fig. 252. The prints D (Figs. 251, 253, 254, and 255) are for tee-grooved cores by which work is bolted to the saddle. A core-box must also be made for these, framed similarly to that in Figs. 256 and 257, but without a bottom board. The bracket E for the back shaft (Figs. 251, 252, 254, and 255) is assumed to be cast on, as is the usual practice in small lathes. It is situated rather awkwardly for casting, being deep and having perpendicular web faces, with bosses, and being close to the edge of the saddle which slides along the rear edge of the bed. A clean and accurate way to mould it would be by putting a block print K (Fig. 255) against one face, and coring out that, with the bosses included by the print, leaving the other face to de- liver itself in the top the saddle moulding upside down. There is, however, the strip shown dotted at c, and this should be cast in order to lessen planing. But to do that would involve leaving the bracket E loosely dowelled, otherwise the edge c could not be moulded. But it is un- desirable to leave such brackets loose, because they are 142 PRACTICAL PATTERN HAK1XG. liable to be rammed out of truth, and thus throw the boss for the back shaft out. On the whole the best plan to adopt is that shown. The bracket is fastened on, and the edge c is cast square, leaving the V to be formed wholly by planing, a lesser Fig. 266. Fig. 267. Fig. 265. Core-box to Form Recess for Screw. Fig. 266. Half Box Opened in Joint Face. Fig. 267. Transverse Section of Core-box. evil than having the bracket cast untrue. But a print might be nailed along the edge as at D, and the strip cored. The bosses on the vertical faces of the bracket are both put on loosely, as also is the one F through which the surfacing screw spindle passes, and the boss faces on E likewise should be loose (Fig. 254). The moulder then joints up to the centre c, and half the bracket delivers SLIDE -RES T PA T TERNS. 143 downwards and half in the top. No holes are cored in it, since that would be troublesome and unnecessary, be- cause such holes should be lined out and drilled through the solid. The remainder of the pattern is self-explanatory. Against the edge G (Figs. 252 and 255) the setting-up strip Fig. 2,0. Figs. 2JJ8 to 270. Swivel Slide Pattern. goes. The faces H (Figs. 253 and 256) receive the apron casting. Such details will vary in different lathes, and need cause no difficulty. These blocks or facings are all fastened on, but taper is given to the inner edges. The pattern of the surfacing slide is shown in Figs. 260 to 262, with dotted lines which indicate cored portions. Fig. 260 is a plan, Fig. 261 a side elevation, and Fig. 262 144 PRACTICAL PATTERN MAKING. an end elevation ; A is the face on which the top slide swivels, and B is a ring print to receive the core round which the clamping bolts move for setting the slide to any angle ; c is a pin cast with the slide to act as a centre pivot. The iixode of construction is indicated by the shading. A core-box (Figs. 263 and 264) will be made for the print B. A central disc and an outer jointed ring being attached to a bottom board will form the annular veed groove, and a hole cut in the bottom board will form that portion of the core at A (Fig. 261) through which the bolts are thrust. As the box is made, the ring portion must Fig. 271. Figs. 271 and 272. Top Slide Pattern. be divided and dowelled, to be withdrawn in halves hori- zontally, on account of the undercutting of the vees. It is maintained concentrically by the annulus or shoulder (see Fig. 264). In a small slide it is better not to core this annulus but to bore it out of the solid. The portion D of the pattern has one square edge, against which the adjustment strip fits, and a bevelled edge which must be put on loosely, either with nails or with dovetails (Fig. 262). The recess for the surfacing screw is cored, E being the print. The core-box is divided and dowelled (Figs. 265 to 267). Fig. 265 shows it in plan, Fig. 266 one half opened in the joint face, and Fig. 267 is a transverse section. The halves a.re dowelled together, SLIDE-HE ST PATTERNS. 145 146 PRACTICAL PATTERN MAKING. and the shape imparted to the interior for clearing the surfacing screw is cut with chisel and gouge. The facing in the centre of the box receives the nut for the screw. Figs. 268 to 270 illustrate the pattern of the top or swivel slide. The construction is so clearly shown that few comments are necessary. There is one core only, a plain rectangular one fitting in the impression of the print A, and the print moulds downwards. There are two loose pieces B, B tacked or dovetailed on the body. The timber grain shows how the stuff is arranged. The top slide (Figs. 271 and 272) is also plain. There is one loose strip and no coring. The apron pattern (Figs. 273 and 274) moulds face down- wards, as shown by the arrow in Fig. 274. A is the boss for the clasp-nut spindle, and B its print for a round core ; c is the boss for the spindle which operates the rack pinion by hand, and D is its print ; E, E are bosses for the rack pinion and intermediate rack pinion, and F is their print ; G, G are guides for the clasp nut; H is a stiffening rib. The planing facings w T hich match those on the saddle must be left loose on the down side, or else the face must be left plain in the pattern. In the castings made from the patterns various holes not shown have to be drilled. Some amount of machining not indicated in the patterns also will be necessary. Some nuts will be required, the patterns for them being just like their castings. Allowances for tooling are to be made where required in pattern work and core-boxes to the extent of about in. 147 CHAPTER XIII. MISCELLANEOUS PATTERNS AND CORE-BOXES. IN making patterns for the screw-down valve shown in section and plan by Figs. 275 and 276, the wood for the trunk of the body pattern (Fig. 277) is in two pieces ; fit them together and then glue a piece of cartridge paper between. All the patterns must be made in two pieces, the joint being at the centre line. When dry the pattern can be turned in the lathe, a brass or iron plate being screwed at each end across the joint, with a countersunk hole in the centre so that it will run true. The nose of the valve is prepared in two halves, trued to shape with the spokeshave. Test it with, say, four templates made of cardboard or thin zinc cut to suit the half finishing to the centre line ; these templates can, of course, be used on both sides, a mixture of tripoli and oil termed rud being put on the edge of the template, which, when applied, leaves a mark at the irregular parts. This process must be' repeated till the parts become quite true. Then the nose can be fixed to the trunk with three dowels, great care being exercised in getting it on true. A chisel driven into the joint will split the paper, leaving the pattern in two halves as desired. The core-box must be very strong to withstand the hammering of the coremaker. Mahogany is very good wood to use, an extra piece being glued and screwed across the grain at the back of each half. The two pieces are fitted together and kept in position with dowels of brass and bushes to suit. Make the box to the outside lines and begin setting out, laying on the flat, side of half the pattern and carefully lining it round. Then remove it and complete the setting out as shown in Fig. 278. Take great care in getting the position of the seating A. Minimise the metal where the article does not require turning, such as inside the body and below the seating, as indicated by the recessed por- 148 PRACTICAL PATTERN MAKENG. tions ; of course, allow extra metal for turning and screw- ing where necessary. When the core-box is put together, describe a circle at the top and bottom end of a diameter equal to the points c s (Fig. 277). Also cut a template to the core at the Fig. 276. Figs. 275 and 276. Vertical Section and Plan of Screw-down Valve. mouth of the valve, mark it on the core-box and cut it out, using very sharp, thin gouges for this purpose. Finish carefully to the lines at the ends and put on a thin band of the rud to show the parts finished. Test the remainder of the semicircular parts with a square. The nose part of VALVE PATTERNS AND CORE-BOXES. 149 the core-box is tested by several templates, and, after being sandpapei'ed very smooth, can be varnished with a ' mixture of shellac varnish and gas black. Fig. 277. Body Pattern for Screw-down Valve. To make a better box in iron or brass, turn a core to the size and shape required and fix the nose on the trunk. This is also made in two halves, and well varnished or Fig. 278. Core-box for Body for Screw-down Valve. painted with the rud and placed in a roughly-made box that holds the core print in position. A quantity of plaster-of-Paris is poured into the box, filling it somewhat 150 PRACTICAL PATTERN MAKING. above the centre line of the print, and is allowed to dry. The plaster is carefully cut down to the centre line, and the wood core print removed, the sides trimmed, and the slots are cut as shown in Fig. 278 ; these afterwards form Fig. 279. Valve-top Cap Tattern. projections to answer as dowels. Then the whole wood print is painted with rud and replaced in the rough wood box, which is then filled with plaster-of-Paris and allowed to set. Cut away all superfluous plaster and take apart, leaving a plaster pattern for the metal core-box. This, when thoroughly dry, may be varnished, then cast, the shrinkage being sufficient to allow of the casting being cleaned up. The pattern of the top cap or stuffing box A (Fig. 275) Fig. 280. Core-box for Valve-top Cap. is a plain turning with a square formed in the middle, as shown in Fig. 279. All the edges are slightly taper, and the ends slightly rounded for ease in moulding, c s being the points. The core-box is illustrated by Fig. 280. Where VALVE PATTERNS AND CORE-BOXES. 151 the square comes the metal is slightly reduced to lighten the casting and to assist the brass finisher. The top part of the cap receives packing cotton. The top part of the stuffing nut B (Fig. 275) is made hexagon shape, the bottom being round for screwing. Fig. 281. Nut Pattern. Fig. 2:>2. Half Core-box for Nut. The nut is immersed wholly in the bottom box of the moulder, and a small core is placed as shown by c s in Fig. 281, the half core-box being shown by Fig. 282. The spindle c (Fig. 275) has a square formed on the top to receive the knob ; the hole in the bottom end is drilled to receive the jumper D. The knob E (Fig. 275) is moulded downwards. The pattern is turned in the lathe, and after- wards cut out to form the four spokes. Fig. 283 shows the core at stays at A. The top receives the pottery plate F (Fig. 275), while the bottom core is squared to fit the spindle. Fig. 284 is a section through the core-box. The jumper is a plain washer with a projection on each side, one entering the drilled spindle, and the other receiving Fig 283. Knob Pattern. Fig. 284. Co.-e-box for Knob. a nut which secures the seating washer w. The fly or running nut G (Fig. 275) is simply a circular screwed washer with a hexagon head. The shrinkage is about $ in. in the foot, and the amount for turning and screwing is about 152 PRACTICAL PATTERN MAKING. VALVE PATTERNS AND GO RE -BOXES. 153 Fig. 285 is a face view of one half of the core-box for a globe valve of the design shown marked, Fig. 286 being a section on A B, and Fig. 287 a section on c D. Two blocks, being jointed and dowelled, are squared at the ends and on the edges where the branch comes. Centre lines on the face being gauged and squared, circles are described on the ends and edge to the print diameters. The shape is scribed round one-half of the pattern when laid on the PRACTICAL PATTERN MAKING. box, and the thickness of the metal is marked within the lines. The semicircular hollow for the prints is worked straight through, and a shouldered template (Fig. 288) is then used to obtain the shape of the swelled part. The hollow for the branch is worked from the edge, the counter-bore of the flange being neglected. A gauge line is run round where the metal is set back beyond the face of the branch flange, and the set-back is worked down to template. The Fig. 281). Fig. 290. Fig. 292. Figs. 289 and 290. Turned Segments for Partitions. Figs. 291 and 292. Method of Working Segments. partition and valve seat must be fitted in four segments, and kept loose so that each piece may be withdrawn by a circular motion from the half-core before the two halves are fastened together. Turn these four segments to the shape shown by Figs. 289 and 290, holding them on a face- plate with a paper joint. To tie them together at the top, glue on four shallow segments to break joint, as the end joints must not be glued, and are, moreover, made to coin- cide with transverse lines passing through the centre of the face-plate. Then fit them into the body of the box, the binding segments being cut away. BULL-NOSE PLANE PATTERN. 155 A better way is to fix two semicircular templates (Figs. 291 and 292) and to sweep around these a shouldered template cut to the reverse of Fig. 288. A shoulder, ex- tending (say) -^ in. into the wood and ^ in. below the joint, determines the positions of the segments. The other extremity of each segment is cut as in Fig. 293, and ends are carried by a small block (Figs. 294 and 295) let into the centre of the box before being worked to shape. This block makes up the partition where it departs from the conical form. Most of the lines upon it may then be marked by a long-toothed gauge. Scribe the inclined dotted lines on Fig. 285 when the section is marked out Fig. 2'.)!. Fig. 295. Fig. 203. End of Segment. Figs. 294 and 295. Block for Ends of Segments. to assist in getting the segments to position. The end of the segment must agree with a straightedge placed along the line. A set-square laid in the semicircle formed by the two segments will test the correctness. A long-toothed gauge, worked against the branch edge of the box, will test the position of the valve seat. One half of the box being worked, the other is scribed from it and the slant lines transferred. As each half of the box is rammed separately, the ends and the branch edge are tapered and closed by pieces being screwed up to them. The transverse backing, which all such boxes should possess, is not shown, and is best fixed before the box is worked. The pattern for a bull-nose plane will be described as a final example. A lengthways section through a brass cast- ing intended for the body of a bull-nose plane is shown by Fig. 296, an end view being given by Fig. 297. The dimen- sion B should be about T Vi n - greater than the width of the wide part of the cutting iron, in order to allow for filing to 156 PRACTICAL PATTERN MAKING. size. The dimension A is about ,^ in. less than B. Fig. 298 represents the pattern, the part exterior to the contour of the casting being a core-print. The pattern is made as follows: A block of wood is planed to a parallel thickness equal to A, and the whole of the shape shown in Fig. 298 is Fig. 296. fig. 297. Figs. 296 and 297. Body of Bull-nose Plane. ' set out on both sides, a slight allowance for draught from the sand being made. The wood is then cut to the outline of the figure. Two thin pieces are then cut out, both having a thickness equal to half the difference between A and B, the outline of these pieces being similar to that Fig. 298. Fig. 298. Pattern for Bull -nose Plane. of Fig. 298. The space for the shaving escapement c (Fig. 296) is also cut away. Fig. 296 shows the face of tho plane- when finished, and Fig. 298 shows the face as it is to be cast. The difference between these views is due to allowances for facing the casting, and if not attended to, an unduly wide mouth will be the result. For castings to be made in iron, it is advisable to glue a little fillet about 3\- in. thick and | in. wide. over the part of the casting which is eventually to become the mouth. This is done in BULL-NOSE PLANE PATTERN. 157 order to prevent the metal being chilled, which would occur if it were very thin. It is also necessary in an iron casting to ensure that the mould is so arranged for casting that the face of the plane occupies its lowest part, or when faced up blow-holes may be found there. The core-box (Figs. 299 and 300) is made of two pieces of wood dowelled together. After the blank pieces are dowelled they are /"s, p; ( i Fig. 299. Figs. 99 and 300. Core-box for Bull-nose Plane. planed up to a thickness equal to A. The main part of the pattern is then laid on the face of the blank core-box in the position shown in Fig. 299, and the shape scribed on the core-box. This is done, of course, before the thin pieces have been glued on it. One of the thin pieces is then laid on the core-box to fit on with the lines already scribed, and its shape transferred to the core-box. That part of the core-box which has to be cut away will then become evident. INDEX. "Angling," or Feather edged Fil- leting, 31, 32 Apron Pattern, 146 Barrel of Lathe Poppet, 131 Bench, Ramming, 21, 22 Bend-pipe, Core-box for, 51, 52 Blocking Pieces, Dowelling, 85 Board, Moulding, 14 Bolt Holes, Searing Iron for, 40 Boss, Capstan, Coring, 70, 71 " Boxing Up," 117 Bracket Casting, Coring Holes In, 71-77 , Double, 81, 82 with Slot Holes, 79 Brass Pattern Plate, 20 , Shrinkage of, 11, 12 Bull-nose Plane Pattern and Core- box, 155-157 Butt Joint, 25 Capstan Boss, Coring, 70, 71 Casting Cylinder, 62-66 Iron Columns, 83-92 Castings, Coring Holes in, 59-82 for Hydraulic Work, 23 Chamber Cores, 53 Channels in Moulds. 23 Chaplet Nails, 66, 91 Charcoal, Dusting Moulds with, 23 Check, Four-part, 25, 26 , Three-part, 25 Cheese-headed Screw Holes, Sear- ing, 40 Circular Core-box, 50 Patterns, 42-49 , Plaster, 47-49 Columns (see Iron Columns) Cope, 13 Core, Chamber, 53 for Iron Column, 91 Prints in Bracket Casting Pat- tern, 72 , Rectangular, 53-55 , Round, 56 , Stopping-over, 74 , Symmetrical, 56 , TTnsymmetrleal, 56 Core-boxes, 50-58 , for Bend-pipe, 51, 52 Bull-nose Plane, 157 , Circular, Worked Out with Set-square, 52 for Cylinder Cover, 60, 61 Cylindrical Core, 50 Exhaust Port, 97 - Flywheel, 56, 57 Core-boxes for Gap Lathe-bed, 1?1 Globe Valve, 153 , Internal Flange Fitted to, 2, for Knob, 151 Nut Pattern, 151 Screw-down Valve, 147 Slide-rest Pattern, 141 Spur Wheel, 57 Steam Chest, 93 Steam-engine Cylinder, , Steam-inlet, 99 , Steam-port, 99, 100 for Surfacing Slide, 144 Valve Cap, 150, 151 Coring Gap Lathe-beds, 117 Hand Capstan Boss, 70, 71 Holes in Bracket Casting 71-77 in Castings, 59-82 Cylinder Cover, 59 62 Stuffing-box, 68 Valve-rod Hole, 68 Corine-out Gap in Lathe-bed, 12?, Corner Half-check, 24 Curved Fillet, Leather Strip for, 33 Cutting Worm Wheel Teeth, 108 Cylinder Casting, 62-66 Cover, Core-box for, 63, 61 , Coring Holes in, 59-62 , Mould for, 61 Pattern, Steam-engine 93 100 Cylindrical Core-box, 50 Dovetail Half-check, 24 Dowel, 29, 30 , Cup and Peg, 30 , Inserting, 30 , Peg, 29 , Plate, 29 Dowelling, 28 Blocking Pieces, 85 Drag, 13 Eight-arm Wheel, Four-part Check for, 25 Exhaust Port Core-box, 97 Eye-side Frame, 17 Filleting, 31, 32 , Feather-edged, 31, 32 , , Strength of, 34, 35 Fillets, 119, 120 - , Curved, Leather Strip for, 33 , Substitute for, 34 Worked out of Flange, 33-34 Worked out of Solid, 33-35 INDEX. Finishing Patterns, 36 41 Flange, Fillet Worked out of, 33, 34 , Internal, fitted into Core box, 52, 53 Flask, 13, 14 , Iron, 15 , Odd-side, Moulding, 17 , Wooden, 13, 15 Floor, Sand, 21 Fly-wheel, Core-box for, 56, 57 Foundry Work, 13-23 Four-part Check, 25, 26 Frame, Eye-side, 17 , Peg-side, 18 Frames, Moulding, 13 Gap-lathe Bed, Coring, 117, 12;?, 124 Pattern, lib Gateway Moulding, 18 Git-hole, Making, 23 Glasspapering Pattern, 36 115 Globe Valve Core-box, 153 Glue, Objections to, 27 Half-check, Corner, 21 , Dovetail, 24 , Middle, 24 , Ordinary, 24, 25 Halving Joint, 24 Hand-turning Lathe, Patterns for, 110-124 Headstock Patterns, 125-130 " Hobbing " Teeth of Worm Wheels, 101 Horns for Back Gear Mandrel Bearings, 127, 128 Hydraulic Work, Castings for, 23 Iron Columns; Casting, 83-92 , Moulding, 83-92 , Patterns for, 83-86 Flask, 15 Pattern Plate, 20 , Shrinkage of, 11 Joint, Butt, 25 , Halving, 24 -, Mitre, 25 Jointing Halves of Pattern, 104 Jointing-up Patterns, 24-35 Joints in Pattern Making, 24-35 , Securing, 47 Knob Patterns, 42, 151 Lathe-bed, Gap, Coring, 117 Pattern, 110-124 . , Gap, 115 , Hand-turning, Pattern of, 110- 124 , Headstoek Patterns, 125-130 Poppet, Barrel of, 131 Patterns, 130-134 Main Pouring, Making, 25 Mandrel Bearings, Horns for, 127, 128 Marking Out Teeth, 107, 108 Metal Patterns, 12 Middle Half-check, 24, 25 Mitre Joint, 25 Mould, Arrangement of Runners in, 22 , Channels in, 23 for Cylinder Cover, 61 Denned, 10 , Drying, 23 , Dusting, with Charcoal, 23 , Loosening Patterns from, 18 , Making Main Pouring in, 23 , Peg-side, 18 , Preparing, 16 , Sand, 13 Moulding Board, 14 in Foundry Work, 16 23 Frames, 13 , Gatework, 18 Odd-side of Flask, 17 , Platework, 18-20 Trough, 16 Tub, 15, 16 Nails, Chaplet, 66, 91 Numbering Patterns, 36 Nut Pattern, 551 , Core-box for, 151 Pan, Circular Pattern of, 47 Pattern, Glasspapering, 36 , Loosening from Mould, 18 Maker, Duties of, 9 , Numbering, 36 , Object of, 9 Plate, Brass, 20 , Iron, 20 , Varnishing, 36 Peg Dowel, 29 Pegs, Steel Plate for Shaping, 47 Peg-side Frame, 18 Mould, 18 Pipe Casting, 77-79 , Pattern Flange for, 77 Plane, Bull-nose, Pattern and Core-bos for, 155-157 Plaster Patterns, 48, 149 Plate Dowel, 29 Plated Patterns, 19, 20 Platework, Advantages of, 20 , Disadvantages of, 20 , Moulding, 18-20 Poppet Barrel, Turning, 132 - Patterns. Lathe, 130-134 , Plain, 134 Pouring Metal into Column Moulds, 91, 92 Prints, Square, 66 Pulleys, Core-boxes for, 56 Ramming Bench, 21. 22 Rectangular Core, 53-55 Ring Casting, Pattern for, 43, 44 Round Cores, 56 Runners in Mould, Arrangement of, 22 Saddle Pattern, Slide-rest, 135 ico INDEX. Sand Floor for Bedding, 21 Moulds, 13 , Tempering, 16 Sawing-board, 44 Screw-down Valve, Core-box for, 147 , Patterns for, 147 Searing, 37-41 Bolt Holes, 40 Cheese-headed Screw Holes, 40 Cone-headed Screw Holes. 40 Iron for Plain Surfaces, 37 Strainer Core-box, 40 Segments, Dog Used for Tightening, - -, Making Pattern In, 43, 44 , Template for, 44 , Tightening, 46 , Working, for Globe Valve Pattern, 155 Set-square, Working Out Circular Core-box -with, 52 Shrinkage, Allowance for, 11, 115 of Brass, 11, 12 Iron, 11 Slide-rest Pattern, 135-146 , Core-box for, 141 Saddle Pattern, 135-146 Slot Holes in Bracket Casting, 79 Spindles, 43 Spur Wheel, Core-box for, 57 Square Prints, 66 Steam-chest Core-box, 98 Pattern, 68, 69 Steam-engine Cylinder Pattern, 93- , Core-box for, 96 Steam-inlet Core-box, 99 Steam port Core-box, 99, 100 Stopping-over Cores, 74 Strainer Core-box, Searing Iron for, 40 Strickle, 48, 49 Stuffing-box, Coring, 68 Pattern, 150 Surfacing Slide, Core-box for, 144 , Pattern for, 143 Taper, Necessity of, 10 Teeth, Worm Wheel, Cutting, 108 , Marking Out, 107, 108 Tempering Sand, 16 Template for Segments, 44 Three-part Check, 25 Trough, Moulding, 16 Tub, Moulding, 15, 16 Turned Patterns, 42 Turning Poppet Barrel, 132 Valve Cap Pattern, 150 , Globe, Core-box for, 153 , Screw-down, Pattern for, 147- 155 Stuffing-box Pattern, 150 - Top-cap Pattern, 150 Valve-rod Hole, Coring, 68 Varnishing Pattern, 36 Wheel, Eight-arm, Four-part Check for. 25, 26 , Marking Out, in Sections, 101, Wooden Flasks, 13, 15 Worm Wheel, " Hobbing " Teeth of, 101 . Marking Out in Sections, 101, 102 Pattern, 101-109 PRIS-TEH BY CASSELI, & COMPANY, LIMITED, LA BKI.I.E SAUVACE, E.G. ENGINEER'S HANDY-BOOK. CONTAINING FACTS, FORMULE, TABLES AND QUESTIONS ON POWER, ITS GENERATION, TRANSMISSION AND MEASUREMENT; HEAT, FUEL AND STEAM; THE STEAM-BOILER AND ACCESSORIES; STEAM-ENGINES AND THEIR PARTS ; THE STEAM-ENGINE IN- DICATOR; GAS AND GASOLINE ENGINES; MATERIALS, THEIR PROPERTIES AND STRENGTH: TOGETHEE WITH A DISCUSSION OF THE FUNDAMENTAL EXPEELMENTS IN ELECTRICITY, AND AN EXPLANATION OP DYNAMOS, MOTORS, BATTERIES, SWITCHBOARDS, TELE- PHONES, BELLS, ANNUNCIATORS, ALARMS, ETC., AND ALSO RULES FOR CALCULATING SIZES OF WIRES. BY STEPHEN ROPER, ENGINEER, AUTHOR OF " Roper's Catechism of High-Pressure or Non-Condensing Steam-Engines,' "Roper's Hand-Book of the Locomotive,'' "Roper's Hand-Book of Land and Marine Engines," " Roper's Hand-Book of Modern Steam-Fire Engines," "Young Engineer's Own Book," " Use and Abuse of the Steam-Boiler," " Ques- tions and Answers for Engineers," etc. FIFTEENTH EDITION. REVISED AND GREATLY ENLARGED BY EDWIN B. KELLER, M. E., AND CLAYTON W. PIKE, B. S., Ex-President of ti^e Electrical Section of the Franklin Institute. PHILADELPHIA : DAVIJ3 MoKAY, G1O South Washington. Square. 1905. PRICE, POSTPAID, $3.50. SEND FOR CIRCULARS. UNIVERSITY OF CALIFORNIA LIBRARY Los Angeles This book is DUE on the last date stamped below. MPR 1819B2 '''"^ OCT 2 3 OCl 21Rf NOV 30 1964 MAR MAR 24 19651 MAR XX 1971 DEC 1 4 1972 TP ^ RFTTl DEC X X 1973 DEC 1 Form L9-lCOm-9,'52(A3105)444 610 South Washington Square, Philadelphia, Complete Descriptive Circulars Mailed Free on Application. Send for them. THE LIBRARY ITY OF CALIFORNIA ANGELES Engineering Library TS UC SOUTHERN REGIONAL 000768161 2 TECHNK iTRUCTION. Important New Series of Pra J * ' ( ^ . Edited by PAUL N. HASLUCK. With numerous Illustrations in the Text. Each book contains about 160 pages, crown 8vo. Cloth, $1.00 each, postpaid. Practical Draughtsmen's Work. '"With 226 Illustrations. Contents. Drawing Boards. Paper and Mounting. Draughtsmen's Instruments. Drawing Straight Lines. Drawing Circular Lines. Elliptical Curves. Projection. Back Lining Drawings. Scale Drawings and Maps. Colouring Drawings. Making a Drawing. Index. Practical Gasfltting. With 120 Illustrations. Contents. How Coal Gas is Made. Coal Gas from the Retort to the Gas Holder. Gas Supply from Gas Holder to Meter. Laying the Gas Pipe in the House. Gas Meters. Gas Burners. Incandescent Lights. Gas Fittings in Workshops and Theatres. Gas Fittings for Festival Illuminations. Gas Fires and Cooking Stoves. Index. Practical Staircase Joinery. With 215 Illustrations. Contents. Introduction: Explanation of Terms. Simple form of Staircase Housed String Stair: Measuring, Planning, and Setting Out. Two-flight Staircase. Staircase with Winders at Bottom. Staircase with Winders at Top and Bottom. Staircase with Half-space of Winders. Staircase over an Oblique Plan. Staircase with Open or Cut Strings. Cut String Staircase with Brackets. Open String Staircase with Bull-nose Step. Geometrical Staircases. Winding Staircases. Ships' Staircases. Index. Practical Metal Plate Work. With 247 Illustrations. Contents. Materials used in Metal Plate Work. Geometrical Construction of Plane Figures. Geometrical Construction and Development of Solid Figures. Tools and Appliances used in Metal Plate Work. Soldering and Brazing. Tinning., Re-tinning, and Galvanising. Examples of Practical Metal Plate Work. Examples of Practical Pattern Drawing. Index. Practical Graining and Marbling. With 79 Illustrations. Contents. Graining: Introduction, Tools and Mechanical Aids. Graining Grounds and Graining Colors. Oak Graining in Oil. Oak Graining in Spirit and Water Colours. Pollard Oak and Knotted Oak Graining. Maple Graining. Mahogany and Pitch-pine Graining. Walnut Graining. Fancy Wood Graining. Furniture Graining. Imitating Woods by Staining. Imitating Inlaid Woods. Marbling: Introduction, Tools, and Materials. Imitating Varieties of Marble. Index. Painters' Oils, Colors and Varnishes. With Numerous Illustrations. Contents. Painters' Oils. Color and Pigments. White Pigments. Blue Pigments. Chrome Pigments. Lake Pigments. Green Pigments. Red Pigments. Brown and Black Pigments. Yellow and Orange Pigments. Bronze Colors. Driers. Paint Grinding and Mixing. Gums, Oils, and Solvents for Varnishes. Varnish Manufacture. Index. Ready Shortly: Practical Plumbing Work. Other New Volumes in Preparation. DAVID McKAY, Publisher, Washington Square, Philadelphia.