SOI* Class Book Copyright}}?. COPYRIGHT DEPOSIR A HIGH SCHOOL COURSE IN WOOD PATTERN MAKING By Joseph Henry Wilson Instructor in Pattern Making, Central High School Washington, D. C. Formerly instructor at McKinley Manual Training School Washington, D. C. 1916 Copyright, 1916 By Joseph Henry Wilson DEC -5 1316 ■0: 1 6 -14115 CI.A446713 PREFACE This book is the outgrowth of seven years of teaching experience in both Trade and High Schools. The author submits the book on the ground that we can all benefit by the experience of others. Works on Pattern Making are not as numerous as the importance of the subject warrants. The various articles in this book follow each other in what seems to the author to be the natural sequence. To begin the subject the teacher lectures on The Metal Trades (Chapters I and II), and the manufacture of iron products, so that the pupil can learn exactly what part pat- tern making plays in the commercial world. Then the wood working exercise in Chapter III should be started. Before beginning it, however the pupils, as a class, should be made to remove the plane bit and sharpen it and learn to replace it correctly. Pupils dislike to take a plane apart until the teacher proves to them that it is a simple operation. While the pupil is working on the exercise, certain periods should be devoted to lectures and recitations on Moulding and Pattern Making, (Chapters IV and V,' so that these chapters are covered by the time the exercise is finished. Then the student will understand and can begin making the simple patterns in Chapter VI. If lathes are scarce in the shop some pupils may be put at turning immediately after the first pattern. These pupils can then go back to the bench while others are turning. From parted patterns, to the end, the time spent on the bench preparing the pattern for the lathe, making the core box and finishing, exceeds the time spent at the lathe and a student need never be idle while waiting a chance to get on a lathe. Each student must have a bench. Each individual kit of tools should be as small as possible. Large kits are difficult to keep track of. Each boy needs only : bevel, square, back saw, gage, scribe, dividers, rule, dust brush, jack plane, block plane, y 2 " chisel, i" chisel, fy" inside gouge, and Y" outside gouge. Sharpening out- fits must be as convenient as possible. If pos- sible supply each bench with an oilstone. Other tools are necessary but as they are not frequently used, a few of each may be kept in a convenient wall cabinet. There should be at least one-third as many lathes as there are pupils in the shop at one time and as many face plates as there are pupils taking the course. A band saw is indispensable. Experience gained while a student at the Wil- liamson School of Mechanical Trades enabled the author to arrange the course and his ten years experience as a pattern maker in large commer- mercial shops enabled him to present actual shop methods. CONTENTS CHAPTER I— The Metal Trades i The Machinery Manufacturing Plant. CHAPTER II— Benefits of Shop Course 6 CHAPTER III— Woodworking 9 Tools. Exercise in Working to Scribe and Gage Lines with Saw and Chisel. Instruc- tion card. CHAPTER IV— Moulding 20 Loam, Dry Sand and Green Sand Moulds, Tools Terms, Cores, Shrinkage of Metals, Shrinkage Rule, Draft, Parted Patterns; making a Mould. CHAPTER V— Pattern Making 39 Definition, Lumber, Drawings, Allowances in Pattern Making. CHAPTER VI— Bench Work 48 Pattern No. 1, Introducing finish, shrinkage and draft, Shellac. No. 2, Introducing Green Sand Cores. No. 3, What to do with small holes. CHAPTER VII— Wood Turning 57 Cylinder, Beads, Coves. Its Relation to Pattern Making. Sharpening Lathe Tools. CHAPTER VIII— Turned Patterns 65 Bushing. To Shellac on the Lathe. A Parted Pattern. Hollow Cylinder. The Core Box. CHAPTER IX— Gouge and Templet Work 75 The Templet, Drip Cup, Built Up Work, Rail Stop, Fillets, Tail Prints. CHAPTER X— Face Plate Work 82 The Chuck or Face Plate, Cylinder Cover, Spear Point Tool, Rechucking, Segments, Piston Ring, Lead Ladle, Locomotive Bell. CHAPTER XI— Wheels 96 Hand Wheel. Gear Blank, Arms, Gear Wheel. CHAPTER XII— Staves and Strips 103 Flange Pipe, Stripped up Core Box, Loose Pieces. Cylinder Cover. CHAPTER I. THE METAL TRADES As you walk along the streets of a city and observe the ornamental lamp posts, the U. S. mail boxes, or the fire plugs, or, as you hear the bell or whistle of a locomotive or the chug-chug of a gas or steam engine, has it not at some time ex- cited in you a curiosity to know the processes by which such things come into being? Did it ever occur to you that the motor in your father's automobile, the parts of your mother's sewing machine, the hardware in your home, the plumb- ing fixtures in your bath room, or the pipe fittings and steam radiators which help make you com- fortable, or even the artistic bronze statues which help beautify your parks, might be produced by processes which would prove to be a great deal more interesting to you than anything into which you have yet inquired? It is the purpose of these pages to get you interested in this art ; the art of manufacturing metal objects, such as those mentioned above, and countless others. To begin at the beginning, let us follow the manufacture of some new machine. Your History has taught you that some clever men such as Watt, Whitney, and Fulton, first perfected certain new commodities, which were 1 2 A High School Course of great benefit to mankind. You call them in- ventors. In those days inventions were produced only after long and tedious experiments with moving models. Nowadays when an inventor conceives a new machine, he sets it down on paper. He figures out its moving parts and their required strength, etc., often without attempting to make a working model. The result is a "drawing." With this drawing he tells others what has been in his mind. Drawing is the universal language of the engineer. The inventor may not have an engineering education. In that case, he is obliged to employ an engineer to design his machine. After the designer has proportioned the parts, the draftsman draws the details accurately to scale and then a tracing and blue prints are made. The blue prints are sent to a pattern maker, who reads them and fixes in his mind the idea that the designer intends to convey. He then proceeds to fashion certain forms in wood somewhat re- sembling the parts of the new machine. These forms are called patterns. The patterns are then sent to the foundry where a workman called the moulder buries them in a special kind of sand and packs the sand hard around them. Then by ingenious methods, which have been anticipated by the pattern maker, he withdraws the pattern from the sand, leaving the full impression of the pattern in the sand. This impression is called the mould. In Wood Pattern Making 3 While the moulder is preparing the mould, the foundryman is firing up his cupola in which he melts bars of pig iron and quantities of scrap iron. When the iron is brought to a molten state, he rams a clay plug out of a tap hole near the bottom of the cupola, letting the molten metal flow down through a trough into a clay lined ladle in which it is carried to be emptied into the mould. When the metal has cooled and is dug out of the sand, it is found to have the shape that was planned for it by the pattern maker and is called a casting. To free the casting from the particles of sand which adhere to it, it is sent to the cleaning de- partment, where it is tumbled around in a large revolving cylinder called a tumbling barrel or it is subjected to other treatment. The cleaned cast- ing now goes to the machine shop. These castings are somewhat rough ; so in order that the parts of the machine we are building can run smoothly together, we must finish them off smooth on the surfaces which come into contact with each other. To that end, the machine shop is equipped with drill presses and boring mills for boring holes, lathes for turning cylindrical pieces, planers and shapers for making flat surfaces so that two pieces may be made to slide smoothly on one another or fit snugly together, milling- machines, and other machines whose variety and functions are too numerous to mention. After the castings have been finished, they are 4 A High School Course sent to the assembling or erecting shop, where they are all carefully fitted together to make the complete machine. Cast iron is brittle, and when made into slender shapes, is in danger of being broken if subjected to a shock. It is desirable to make such parts from a tougher material; therefore, wrought iron is used. Wrought iron cannot be melted in the cupola and poured into the mould. It is made red hot and hammered into the reuired shape. This work is done in the forge shop. The student should know the above depart- ments in their proper sequence and the function of each. Departments Constituting a Machinery Manu- facturing Plant and Their Functions i. Drafting room: where the machine is planned and drawings made. 2. Pattern shop ; where the forms for use in making the moulds for the parts are made. 3. Foundry ; where the moulds and castings are made. 4. Forge shop ; where the wrought iron parts are hammered out. 5. Machine shop ; where the castings are finished. 6. Assembling shop ; where the machine is fitted together. Compare this with a modern technical high In Wood Pattern Making 5 school and you find that the high school is often a complete machinery manufacturing plant. In a commercial shop the apprentice to any one of the above trades learns only his own trade. Think of the tremendous advantage you have over him since you will get a knowledge of all. CHAPTER II. BENEFITS OF SHOP COURSES You may wish to finish your education at an engineering college. Then you must know the trades, for they are the very foundation of en- gineering. You may wish to be a draftsman. You will then be required to make drawings of objects that are to be made by the processes involved in these trades. Your knowledge of these processes will serve you, in that you can design the objects so that it will be possible to make them by these processes. You will be more valuable to your employer than the office trained draftsman. You may live in a community where the manu- facture of iron products is the chief industry and there is a great field for mechanics. It would be natural for you, under these circumstances, to wish to learn one of the trades and you would be apt to think the others of no importance to you. As a matter of fact, a knowledge of the other trades would make you a broader and more efficient mechanic in your own line and you would rise above the average. In no trade, however, is a knowledge of the others as essential as in the trade of pattern making. The pattern maker must understand mechanical drawing as well as the draftsman himself under- 6 In Wood Pattern Making J stands it ; for he must not only read the drawing, but actually lay it out full size, no matter how large, before beginning the pattern. Every pat- tern shop possesses a stack of large and small drawing boards one of which is selected by the pattern maker who places it on a pair of horses, planes off the old drawing and proceeds to lay down a full size drawing of his new job ac- curately, scratching the lines on the board with a sharp scribe or knife. It is obvious that the pattern maker must know moulding; since he must anticipate the needs of the moulder and so arrange the parts of the pattern that the moulder can draw the pattern out of the sand without breaking down any part of the mould. He must understand enough about machine shop practice to be able to act on his own account in such matters, as adding metal here or there for the machinist to plane or turn off in order to get a smooth surface on the cast- ing. It often happens that he must decide where to put certain lugs or projections on the pattern, which do not appear on the drawing, but which are used by the machinist in chucking or center- ing the work in the machine. In addition to this knowledge, the pattern maker must be highly skilful with the wood work- ing tools in order to produce patterns which are smooth and clean cut. The ability to operate machine tools or wood working machinery is necessary. A surprising variety of work can be done on such machines by one who will take the 8 A High School Course trouble to learn how. An illustration of what can be done on the circular saw can be found in the Oliver Catalog, Students in elementary pattern work will, however, have little except plain work on these machines. Above all, the pattern maker must possess re- sourcefulness and be willing to use it continually, No mentally lazy person can become an efficient pattern maker, Any number of castings can be produced by the use of a single pattern ; therefore, the pattern maker seldom has two jobs alike, Each new job calls for original thinking, planning and scheming. This thinking covers the whole range of the metal trades. While the pattern maker works in wood, he has little in common with the carpenter and cabinet maker. His thoughts are mostly on metal. Therefore pattern making is classed among the metal trades. From the foregoing it will be seen that in order to complete a course in pattern making hard work is requited. Your teacher has a right to expect it from you. He has a right to suppose that you want this kind of work or you would not attend a manual training school. If you lean toward business or a profession you should have attended a commercial or academic school. But the author wishes to state that one who has no intention of following a mechanical pursuit, will find that the knowledge gained in this work will give him greater satisfaction, in after life, than many other things he has learned at school. CHAPTER III WOODWORKING. Exercise I. (See Drawing, Fig. 8.) Most pupils who take a course in pattern making have had a course in woodworking or cabinet making in the lower schools, therefore, it is not necessary to begin at the beginning. Many bad habits in the use of tools are formed by pupils, however ; so this exercise, while it has nothing to do with pattern making, will serve as a review for the student and an opportunity for the teacher to correct bad habits before the more serious business of pattern making is taken up. As will be found later, the pattern maker's thoughts and reasoning are mostly in metal ; therefore the student should be so familiar with wood work before he begins on patterns, that the wood working will not give him much concern. Considering then that the student has handled tools before and knows something about them, we will call attention only to the common mis- takes found in all school shops. io A High School Course The The first tool that we use is the iron Plane jack plane. Since the rough stock from which we make this exercise is only about i2y 2 " long we shall use the jack plane for smoothing and for truing the surfaces. If we had to plane very long pieces we should use a fore plane; but since none of our work is very long, the individual kits need not contain a fore plane. A pattern maker has not mUch use for a smooth plane; because it is seldom that he wishes simply to smooth a piece without truing it. The best thing to do first, is to remove the bit from the plane, examine the parts, see how they work, and learn to put the bit back in place and lock the cap. Do this enough times so that you lose all fear of doing it and will not hesitate to do it, in the future, when the bit needs sharpening. Under the direction of the teacher learn to do it gracefully. This can best be accomplished by holding the plane with the bottom flat in the left hand and drawing the cap-cam up with the right. Do not let it snap as it may break off. To avoid a common mistake in replacing the bit, hold the plane on a level with the eye and see that the bit lies flat upon the frog. In order for the bit to lie flat, the little finger which forms one end of the "Y" adjustment, must penetrate the square hole in the plane-iron cap and the little disc on the lateral lever must engage the slot in the plane- iron. If you are careful about this, the cap-cam will go down easily. In Wood Pattern Making ii Fig. I In using the plane, most boys allow the rear of the plane to droop downward before the shaving begins (Fig. i), and when the plane has gone nearly the full length of the piece, and the knob is just passing the far end, they allow the front end to droop. This procedure will cause a hump or a hill to be planed on your piece. You can never plane a piece true, until you have learned always to keep the bottom of your plane parallel with your piece as it lies flat upon the bench (Fig. 2). Fig. Do not put the piece in the vise. If you push your plane straight to the bench-stop the piece will not dance around. The objection to putting 12 A High School Course the piece in the vise is that too much time is lost opening and closing the vise to test the piece. You cannot afford to lose time in this course. Modern times demand efficiency from the workers ; so we may as well begin, right now, to omit unnecessary motions. Before planing, always run your finger lightly over the corners of your bit. If one corner pro- jects farther than the other, change it by shifting the lateral lever. Never take a deep bite. Sharpening The most disliked and at the the Bit same time the most necessary op- eration in wood working is sharpen- ing the tools. Too much stress cannot be laid on the importance of keeping the edge of the tools keen. Every boy should be provided with an oil- stone which is kept perfectly flat. In whetting a tool on an oil stone, try to maintain the bevel which is ground on the tool, raising the handle only enough to cause the edge to grind on the stone. Notice that one side of a paring tool is always Hat. Keep this side Hat on the stone and NEVER raise the handle or you will ruin the effectiveness of the tool. (Fig. 3.) ^ , = crxo J j 0//-S?Ofre 6>0)t. 1 "— Fig. 3 In Wood Pattern Making 13 One lesson from the teacher, if he gives you personal attention, will prove that in a very few minutes, you can sharpen a tool, so that you could shave yourself with it ; and this accomplishment will make you so happy that you will never again try to work with a dull tool. Try- The next tool we use is a try-square. Square It consists of a blade and a beam. Always hold the square loosely in the right hand, grasping the beam at its mid point (Fig. 4), and, when squaring an edge or end, see that you press the beam firmly against the Face Side or Face Edge, allowing the blade to touch lightly the sur- face being tested. Pig- 5 Fig. 4 Fig. 6 Gage The gage is an instrument that boys have difficulty in using. The great mistake is that they dig the spur into the wood so deeply 14 A High School Course that the head will not slide freely along the Face Side or Face Edge. (Fig. 5). To avoid this, tilt the head over until the corner of the beam bears on the edge that you are marking and the pressure rides mostly on this corner, leaving only enough pressure on the spur to make a fine light hair line. (Fig. 6.) Scribe ' No pencil line is sufficiently accurate for this course and its use cannot be permitted. All laying off must be done with a scribe or knife, which must be sharp. The line must be deep and clean cut. It must be a hair line and we must work so accurately that by the expression "Working to a line" we mean splitting this hair line. These lines not only serve as a guide but also when planing off an end, prevent the little slivers from breaking out beyond the line and make a clean cut, square corner. Lay out everything with a knife accurately; then split the line and your work will be done correctly in one-fourth the time taken by the man who is too lazy to lay out the work, but takes off a shaving and then measures or tries the square and then takes another shaving, etc. This "cut and try" method does not make for efficiency. Back The chief difficulty in using this tool is Saw to get the cut started. It is a mistake to put the teeth flat on the piece and try to start the kerf parallel with the line. You must start the kerf on the far corner. Hold the piece tightly In Wood Pattern Making 15 against the bench hook with the left hand and then, without exerting pressure on the saw, draw the teeth across the corner at an angle to the surfaces, gradually lowering the handle as the kerf progresses, until the kerf is parallel to the line. (Fig. 7.) In these exercises you must never let the saw touch the line, but go very close to the line leaving only enough so that you can pare off a slight shaving with a plane or chisel. Fig. 7 Block This little plane is used for planing end Plane grain on small blocks. Right here you should learn that, in order to cut wood smoothly, the tool must be given a lateral or side- wise movement, as well as a forward movement, otherwise you would squeeze the wood off, not cut it. To make this plain, imagine yourself cut- ting fresh bread. In this case you draw the knife 16 A High School Course toward you as well as press it down. This Drawing Cut will be insisted upon in all block plane and chisel work, where the wood fibers must be severed. This is not necessary in cutting "with the grain." The block plane should be held al- most wholly within the right hand and the bit allowed to pass across the work at 45 ° to the edges and be drawn across the grain at the same time that it is pushed forward. The result should be a polished surface. Bevel This is like a square with an adjustable blade, so that, with it we may draw lines at other angles than 90 . Chisel It is foolhardy to attempt to use any but the keenest edged chisel on this work. You now know how to sharpen a plane bit. A chisel is much easier to sharpen. The same caution for whetting applies here : "Keep the back flat." Two other necessary precautions are : "Use the drawing cut," and "Keep the brake on." By the latter is meant that you must keep your left hand rigidly braced against the job and allow the tool to slide between the thumb and fore- finger, being ready at any time that the tool threatens to slip, to clamp the fingers together tightly and arrest the tool, before it slips out and splits away some of the wood that you didn't intend it should touch. In modern industrial management it has been In Wood Pattern Making 17 found of advantage to issue instruction cards to mechanics, outlining in their proper sequence the operations which shall be performed on each piece of work. If this is an advantage to an experienced mechanic certainly it is of far more help to the inexperienced one. Below is an outline of op- erations for making the first exercise. INSTRUCTION CARD Exercise in Working to Scribe and Gage Lines with Saw and Chisel 1 . Saw out a piece of rough white pine about 1" X 2 J A" X 12^". 2. True the Face Side with a jack plane and mark it. (To test the first side ; hold it up to the light parallel with the line of sight. If one corner appears high, plane it off and then test all over with the back of the square blade.) 3 . True the Face Edge and mark it. (This must be squared with the face side. Hold the square as explained under "Square.") 4. Plane the second side parallel to the Face Side. (Use gage lines to lay off the thick- ness.) 5. Lay off one end with knife and square. Saw off very near to line and plane to line with a block plane. (Always clamp beam of square tightly to either Face Side or Face Edge, no other. Line must run all around the piece.) i8 A High School Course E CO S CO ^0 In Wood Pattern Making 19 6. Lay off the length and plane the other end. 7. Plane off the second edge parallel to the Face Edge. (Using gage lines to get the width.) 8. Measure along one edge and point off location of the lines for the gains. (Hold rule firmly against job, the divisions on the rule meet- ing the corner you wish to mark. Do not move rule each time you make a mark.) 9. Draw the outlines of the gains. (Use the following tools : bevel, knife, square, and gage.) 10. Saw just inside the knife lines in each gain, leaving very little to chisel off. 11. Chisel out the bottoms of the gains with a i-inch chisel. (Use the drawing cut.) 12. Chisel off the sides of the gains. (Use the drawing cut.) 13. Stamp your name and section on end of piece with steel letters. (Stamp name on end grain on every exercise.) While the student is spending his shop periods making this exercise he should be spending his recitation periods acquiring a theoretic knowl- edge of the metal trades so that he can grasp the meaning of pattern making before he attempts to make his patterns. CHAPTER IV. MOULDING Moulding is of such importance to the student of pattern making that it is well to give him an insight into it, at the outset. If there is no foundry connected with the school, at least one moulding bench should be equipped and main- tained for demonstration purposes. The purpose of these pages on moulding is not to give a complete course in moulding, but to give enough data so that by following the direc- tions here given enough moulding can be done to demonstrate and make clear in the mind of the student just what happens to a pattern after it leaves the pattern shop ; to impress him with the importance of designing his pattern to suit the needs of the moulder. A mould in connection with the foundry busi- ness, is a shaped opening in the sand into which hot metal is poured in order to produce a casting. There are three classes of moulding: i . Loam moulding. 2 . Dry sand moulding. 3. Green sand moulding. Loam moulds are used for casting very heavy, plain pieces ; for example, a large, cylindrical drum 20 In Wood Pattern Making 21 for hoisting. The loam is a mixture of old mould- ing sand and chopped straw, which, when properly dampened, makes a plaster-like mass. This is plastered on a circular brickwork support, built to the approximate diameter, upon a large iron plate. A sweep is revolved on a spindle erected at the center. This will sweep a smooth round layer of loam on the inside of the circular brickwork. The surface is now dried and the whole thing lowered into a pit and packed around with sand to strengthen it, so that the weight of the metal will not burst out the side. The smooth surface will form the face of the drum. The hub and arms may be made in dry sand forms. It will be noticed that no large pattern is used in making this mould ; but the pattern maker must be familiar with it, because he will be called upon to make the sweeps, or skeleton patterns, which may be required. Dry sand moulds are used for casting heavy work having considerable detail. A good example of this is a large steam engine cylinder, with its flanges, steam chest, exhaust outlet, etc. This mould is made in the same way as the green sand mould, which will be described in detail later ; but is thoroughly dried in an oven before pouring. The hot metalflowing in, causes less steam than in a green sand mould, and the hard caked mould offers more resistance to the heavy metal. Green sand moulds, by far the most frequently used, are used for making medium and small cast- 22 A High School Course ings. The material used for making a mould is called moulding scmd and is found in nature. It is found at various places in the United States and brings a good price. It is a combination of sand and clay. The sand component serves as the heat resisting element and its open grain keeps the mould porous, so that the steam and gases may find their way to the vent holes. The clay component serves to bind the particles of sand together so that the mould may be made to retain its form. Obviously clay alone could not be used, as the heat of the metal would bake the clay around the casting, like a brick. The sand causes the dried matrix to crumble easily, so that the casting may be removed. There are two branches of green sand mould- ing: bench moulding and floor moulding. Moulds for machine parts, such as a lathe bed, lathe leg, bandsaw frame, etc., are made in large flasks on the floor. Small things, like water faucets, small pipe joints, etc., are moulded in small flasks, on a bench, for convenience in handling. We shall confine our attention to bench mould- ing; as it will serve to illustrate the principles of moulding which the student of this course must know. Tools Used in Moulding i. Flask: an open wooden or iron frame, in In Wood Pattern Making 23 two or more sections, into which the sand is packed to make the mould. (Fig. 9.) Fig. p. Flask 2. Cope : the upper half of the flask when in position for moulding. 3. Drag: the lower half. 4. Cheek: the intermediate portion when the flask consists of more than two parts. 5. Mould board : a flat board on which the pattern and drag are placed for ramming up. (Fig. 17.) 6. Bottom board : similar to mould board, on which the flask rests after rolling over. (Fig. 18.) 7. Pattern : a near model or form by the use of which the mould is made. 8. Rammer: an instrument used for packing sand into the flask. (Fig. 10.) 9. Sprue pin : a cone shaped piece of wood which is rammed in the cope and which, when 2 4 A High School Course withdrawn, leaves a hole for conducting the metal into the mould. (Fig. n.) Fig. 10. Rammer Fig. ii. Sprue Pin 10. Gate cutter: a bent piece of brass fitted with a handle, and used for cutting a channel leading from the bottom of the sprue hole to the mould. ii. Trowel: a flat, handled blade used for smoothing large surfaces. 12. S 1 i c k e r : a double ended (leaf and spoon) instru- ment used for smoothing flat and rounded surfaces and for patching. (Fig. 12.) Fig. 12. Slicker In Wood Pattern Making 25 13. Corner slick: used for patching corners. 14. Vent wire : a handled rod for piercing holes through the sand to the imbedded pattern to allow the air, steam and gas to escape. 15. Draw screw: a threaded rod which is screwed into the imbedded pattern to act as a handle for pulling the pattern out of the sand. 16. Swab : used for dripping water around edge of pattern to strengthen sand. Terms 1. Ramming up : packing sand in flask. 2. Sprue : opening through the cope left by sprue pin. (Fig. 14.) 3. Gate: channel connecting sprue and mould. (Fig. 14.) 4. Vents : openings provided for escape of gases, air and steam. 5. Gases : formed by combustion of organic matter in the sand and by chemical reactions in the cooling metal. 6. Rapping: gently tapping pattern to loosen it from surrounding sand. 7. Drawing: removing pattern from sand. 8. Pouring : filling mould with molten metal. 9. Shaking out : dumping sand and casting out of flask after metal is hardened. Cores A hole through a casting or an internal cavity in a casting is made by using a core. A core is a body of sand projecting into, 26 A High School Course or supported in the mould. The metal flowing into the mould will surround the core and after it cools the core sand can be cleaned out leaving an empty space. The core must have the same shape as the required cavity. This is accom- plished by ramming core sand into a core box. A core box is made of wood, its interior carved out to the same shape and size as the required cavity in the casting. (Figs. 15 and 20.) The core box is often made in halves, held together with dowel pins. The halves can be separated and the core dumped out. Large core boxes are built up. (Fig. 86.) It is the pattern maker's duty to make the core box. It is considered part of his pattern. Core sand is a combination of sharp sand and flour water, molasses water, or stale beer, the function of the last named being to bind the sand together so that it will hold its shape. The core is dumped from the core box upon an iron plate and placed in a core oven to bake. When baked, it is a hard mass that can be handled with- out fear of breaking. Core making is a separate trade. The hard core can be placed in the proper posi- ton in the mould. The pattern maker has antici- pated this and has provided means for marking the resting place of the core. This he accom- plished by making projections on the pattern (Fig. 13-3) the size and shape of which were determined by the size and shape of the hole In Wood Pattern Making 27 or cavity in the casting, at the point where the hole or cavity cuts through the casting. These projections are called core prints. Therefore, core prints are projections on the pattern which mark out in the mould the resting place of the core. The core sand is easy to remove from the in- terior of a casting because the hot iron burns out the flour or molasses and destroys the bond, leaving the grains of sand free to flow from the cavity. Cores must be provided with vent holes to carry off the gases which form around them. Vertical cores are those which stand on end in the mould. (Fig. 14.) Their upper ends must be cone shaped and the cope core print is similarly cone shaped, so that, when the cope is lowered, the upper end of the core will be sure to enter the tapered hole formed by the cope print. This also serves to bring the core to a vertical position in case it had been leaning. Horizontal cores rest on two or more supports, one at each end. (Fig. 18.) Balanced cones have a free end projecting into the mould. In order to hold such a core in place the end which is supported is enlarged to be heavy enough to balance the free end. Such a core may also be held in position by chaplets. All the cores above are dry sand cores; but there there is another kind called a green sand core, which is formed right in the hollow pattern and is 28 A High School Course — * ^ • .- 1 1 Fig. 13 In Wood Pattern Making 29 left standing when the pattern is withdrawn. This is spoken of as the pattern "leaving its own core." Fig. 13 illustrates what has been given above. Fig. 14. Section View of Mould for Bushing, Ready to Close Fig. 1 3- 1 shows! an ordinary bronze bushing. Fig. 13-2 shows a regulation shop drawing for 30 A High School Course the bushing. In this case the pattern maker de- cides that the most convenient way to get the hole through the casting is to make use of a dry sand vertical core and to mould the pattern on end. Core prints are therefore provided to hold the core in place. Fig. 13-3 shows the pattern with its core prints. For convenience in ramming up this pattern, the cope, or tapered print, is not fastened to the pattern permanently, but is held in its proper place by a pin and can be easily removed. Fig. 14 is a cross section view, through the center of the mould for the bushing. The flask can be seen filled with sand in which the pattern has been imbedded and withdrawn, leaving its impression in the sand. The core is seen stand- ing on end, its lower end fitting snugly into the impression left by the drag print, and its upper end tapered to insure its entering the cope print. Notice the sprue running through the cope. The metal is poured into the sprue from the moulder's ladle, and finds its way into the mould through the gate. For heavy casting, the cope must be weighted or clamped down to prevent floating and a conse- quent leak between the flasks. Fig. 15 shows one-half of the core box in which the core is made. In Wood' Pattern Making 31 Fig. 15, Half of Core Box for Bnshin. Shrinkage It has been found that molten cast iron (C. I.) while cooling shrinks in size, until it is just at the point of solidification, when there is a slight expansion and then a further contraction, until it reaches the temper- ature of the atmosphere. This shrinkage occurs in all the dimensions of the casting and has been found to approximate Y% shrinkage per foot of dimension. If one wished to xast a bar of iron one foot long he would be obliged to make his pattern I2}£" long. The metal would be poured into a 12^" mould, but after all shrinkage had occurred the bar of cold metal would be 12" long. If it were de- sired to have the same bar one inch thick it would be necessary to make the pattern 1" plus 1/96" thick because if the shrinkage is y in 12", in 1" it would be 1/12 X }i = 1/96", and so on, for every dimension. From the foregoing, it would 32 A High School Course appear as if much laborious calculation is neces- sary in pattern making. This is not the case, however, as the pattern maker provides himself with a Shrinkage Rule This rule looks like a standard two-foot rule ; but if compared with a standard rule it will be found to be T /\' longer or 24.34" long. This length is divided into 24 equal spaces. Each space must, therefore, be 1 1/96 standard inches long. These are again subdivided into divisions corresponding to the eighths and sixteenths on a standard rule. One has only to measure every dimension on his pattern with a shrinkage rule to give the necessary increase in size to overcome the loss caused by shrinkage. Steel shrinks 3/16" per foot; brass (Br.) 3/16" per foot ; and other metals have different shrink- ages. The pattern maker must provide himself with a rule for each. Draft In order to make it easier for the moulder to draw a pattern from the sand the pattern maker tapers the vertical sides of the pattern. This taper is called draft. The custo- mary amount is Y%" per foot in height. Where the height is only an inch or two, the taper cannot be measured, therefore the nearest one can come to laying down a rule for it is to say that only a slight taper is necessary. In Wood Pattern Making 33 Parted A pattern of cylindrical shape is dif- Patterns ficult to remove from the sand. Here again the pattern maker makes it easier for the moulder by making the pattern in halves, loosely held in their proper relation to each other by dowel pins. This is called a parted pattern. The half containing the dozvel pins is called the cope half and is moulded in the cope flask. The half containing the dowel pin holes is moulded in the drag flask and is known as the drag half of the pattern. The pipe joint (Fig. 16) Pipe Joint spoken of in the following chapter requires a pattern of this class. Most parted patterns are parted on their center line. However, patterns whose shape is not sym- metrical must be parted on some other line de- 34 A High School Course termined by the direction of the draft on either side of this line. Though it is customary to part cylindrical pat- terns, it is often found expedient to make the pattern solid and allow the moulder to cut his parting with a trowel. That is, he imbeds the whole cylinder in the sand and then cuts the sand away, down to the center line, rams up the cope and allows the cope to lift off the impression of the upper half of the pattern. The pattern now has nothing to impede its withdrawal from the sand. This will readily be understood after the student has seen a demonstration in moulding. Making a Mould for a Small Pipe Joint The sequence of operations to be followed in making this mould follows : i . Place the drag half of the flask, pin holes down, on the moulding board. 2. Place the drag half of the pattern, flat side down on the moulding board inside of the flask. (Fig. 17.) 3. Place the sieve on top of the flask, fill with facing sand, and shake until the pattern is completely covered. (This removes any lumps which would cause rough spots on the casting.) 4. Shovel common sand on top of this until the flask is heaped full. 5. Pack the sand hard with the rammer. (Use In Wood Pattern Making 35 the peen to get close to the edge and use the butt in the center.) 6. Strike the sand off level with the top of the flask, with a straight edge. 7. Make the vent holes. 8. Sprinkle a little loose sand over the top and rub down the bottom board to a good bearing. 9. Clasp both boards and flask together firmly and roll over. 10. Remove the moulding board. 11. Fit on the cope half of the flask. 12. Fit on the cope half of the pattern. 13. Sprinkle on parting sand. 14. Push the end of the sprue pin into the drag sand allowing the main body of the pin to extend upright through the cope. 15. Fill the cope flask full of sand, ram up and strike off. 16. Make vent holes. 17. Remove the sprue pin. 18. Place the moulding board on top of the cope. 19. Carefully lift the cope, turn over and put aside. 20. Drip water around the edge of the pattern with a sponge or swab. 21 . Cut the gate from the sprue to the pattern. 22. Insert the draw screw, rap and draw both halves of the pattern. 23. Dress up any portion of the mould which may have been accidentally broken. 24. Place the core in position, its ends resting in the core print spaces. (Fig. 18.) 36 A High School Course 25. Close the mould. 26. Pour in the melted metal. 27. When sufficiently cooled, shake out. 28. When cold, chip off the gate, clean the sand off the outside and clean the core sand out of the inside. We now have what is known as the casting. (Fig. 16.) Fig. 17. Pipe Joint Pattern in Flask, Ready to Ram Up In Wood Pattern Making 37 38 A High School Course ■y •• .-. ••.«•:•.! » » Fio-. /p. Cor^ /or £/^ Fi^^ /omi Fig. ,?o. //a// 0/ f/i£ Cor£ Box for the Pipe Joint Core CHAPTER V. PATTERN MAKING Pattern making is the art of making forms, or near models, by the use of which sand moulds are made. An extended range of thought, skill, and ex- perience is necessary for efficient pattern making. The pattern maker must possess a greater variety of talents than the mechanic of any other branch of the metal trades. Owing to the great field which it covers, a course in pattern making offers an unusual opportunity for mental development in addition to training the hand. Lumber The material from which ordinary wood patterns are made is white pine. The best quality of white pine for the pattern maker's use, is known as Michigan white pine. It grows in Michigan and the adjoining northern states. It grows in immense trees, from one hundred to two hundred feet in height and two to four feet in diameter. It is soft, very light in weight, of almost a cream color, is durable, warps little as compared Avith other woods, can be easily worked with wood worker's tools and usually has a very straight grain. These proper- ties make it very desirable for pattern making : 39 40 A High School Course but owing to its growing scarcity it is becoming very expensive. Therefore, if you are given white pine from which to make your patterns, be very economical in its use. Be sure to learn the dif- ference between white pine and the other soft woods usually found around a manual training shop, and use only white pine for your patterns, if you want them to retain their original shapes. Patterns which are to stand extraordinary use, that is, which are to be used hundreds of times in the foundry, are made of hard woods, such as mahogany, cherry or walnut, all of which are easily worked, considering that they are hard woods. Lumbering and sawmilling should be inter- esting to a student of this course and much inter- esting reading can be had on the subject. The seasoning of lumber is of such importance that we must give it some attention in these pages. By seasoning we mean "Drying out the sap." When trees are felled they contain 50% by weight of moisture, due to sap which circulates through the tree. By a long period of drying in air, in a sheltered place (two years for a 1" board), this moisture can be reduced to 12 or 15%. As the wood loses its moisture, it becomes consider- ably smaller : in other words, it shrinks. There- fore, if we wish to make a wooden object which is expected to retain its original size and shape, we must be careful to use well seasoned lumber. The moisture in a 1" board can be reduced to 5 or 6% in a few days in a dry kiln (a dry kiln is a In Wood Pattern Making 41 steam heated compartment heated to about 180 .), but when brought out of the kiln it absorbs moisture from the atmosphere until it contains the usual 12 to 15%. The amount which it con- tains varies with the moisture in the atmosphere. This explains why wood continually changes and why furniture often creaks, seemingly without cause. Certain laws govern these changes and the pattern maker must familiarize himself with them. He must anticipate what changes will occur and build his pattern so as to minimize the ills. Thus framing up a wide flat pattern (Fig. 21) and stav- ing up a large round pattern (Fig. 22) would be resorted to, in order to do away with a wide cross grain and its consequent shrinkage; and open joints would be resorted to, in order to distribute the shrinkage evenly; and battens (Fig. 23) would be used to hold a curling piece straight. In the Fig. 21. Large Flat Pattern Framed Up. Open Joints Between Boards Distributes Shrinkage and Swelling Equally 4 2 A High School Course latter case, as the battens form no part of the casting, the moulder fills them up. Instructions to the moulder fill up must be painted on the battens with black shellac. 7 Fig. 22. Half of a Large Cylinder, Staved or Lagged Up. Fig. 23. Battens If wood is allowed to lie flat on the bench in a warm room its upper surface will dry out and contract, causing an upward curl. (Fig. 24.) If a board is allowed to lie flat on the bench in In Wood Pattern Making 43 a damp atmosphere, the exposed side will absorb moisture from the atmosphere and swell while the under side is protected and remains the same size, causing it to curl concave down. (Fig. 25.) Fig. 24 Fig- 25 Fig. 26 The old wood at the heart of the tree will dry out less quickly than the newer open grain sap wood near the bark ; so a board has a tendency to curl away from the heart. (Fig. 26.) For this reason, a pattern maker, in making a job which is very particular, would select a board which is sawed radially with the log, or a quarter sawed board. To determine a quarter sawed board, one 44 A High School Course must inspect the annual rings on the end of the board. (Fig. 27.) P/a//? Sawed Fig. 27 Quarter The porous, end grain of a board dries and con- tracts more quickly than the solid mass of wood, causing a strain and finally a split. This is called a check and may be prevented by shellacing the end, immediately after it is trimmed off. The unit of board measure is the board foot. Drawings Drawings are representations of the finished iron object. They are made for the machine shop, to guide the machinist in cutting, boring, planing and fitting, so as to pro- duce an object embodying the general require- ments. No drawing of the pattern is furnished for the pattern maker. The pattern maker gets what information he can from the machine shop In Wood Pattern Making 45 drawing and then makes, from his imagination, some form in wood, which the workman following him can use to produce the required object. The pattern often does not look like the desired object, but bears only a general resemblance to it. Draw- ings are seldom made full size. The pattern maker lays down a full size drawing of the pat- tern on a board, making the lines with a knife instead of pencil. Drawings are seldom correct. Dimensions are often changed on the blue-print, without making a corresponding change in the lines ; therefore keep to the given dimensions and scale the draw- ing only when the draftsman has omitted the dimensions. The blame for a mistake then rests upon the draftsman. The style of drawing used in shop drawing, is called orthographic projection. Practically all high schools that have a course in pattern making, also have a course in mechanical drawing; there- fore instruction in drawing will be left to the Mechanical Drawing Department. Allowances There are three additions not in Pattern called for on the drawing, which Making the pattern maker must put upon the pattern; namely, finish, shrink- age, and draft. Finish is an addition of %" of extra metal on all surfaces which are to be machined smooth in the machine shop. (Fig. 29.) Surfaces which fit 4 6 A High School Course together, slide on one another, or revolve one in the other, are treated in this manner. Such sur- faces are indicated by a little "f" on the draw- ing. The "£" crosses the line representing the surface to be smoothed. (Fig. 28.) C q/incfer Poire/ 1 . CasfIro/7 . Fig. 28. Shop Drazving of Cylinder Cover In Wood Pattern Making 47 Shrinkage is an addition of y%" per foot to over- come the loss caused by the shrinkage of the metal in cooling. This shrinkage of metal is ex- plained under Moulding. Draft is a slight taper (%" per foot) on the vertical sides of patterns to facilitate the with- drawal from the sand. (Fig. 29.) 1 I Ji Tfos /tfti our wtfh fJre cape.. J *c ^ fa;*/, v : — ----- r Fig. 2p. Drawing of Pattern for Cylinder Cover Showing Allowances. Measured with the Shrinkage Rule The pattern maker's drawing must show that these allowances have been added. A sample shop drawing and a pattern drawing are given in Figs. 28 and 29. Students must follow this form. Fig. 28 is a sample of the kind of drawing- usually furnished to the pattern maker. It is a picture of the finished cast iron object. Fig. 29 is a sample of drawing made by the pattern maker from information given by the shop drawing plus the allowances which he knows he must add. This is a picture of the Pattern. Note the difference. Frequently as in this case, a cross-section only is required. The pattern maker omits the plan view and dimen- sions, but makes the drawing full size. CHAPTER VI BENCH WORK Pattern No. i, Introducing Finish, Shrinkage and Draft The drawing opposite represents a machine shop exercise in chipping and filing. In order that the machine shop student may produce this object, he must be supplied with a block of cast iron of the approximate shape. The foundry furnishes this block; but in order to produce it, the foundry must be supplied with a pattern. The pattern shop is responsible for the production of the pattern. The first thing to do in making a pattern for this, is to make a drawing of the pattern. As you have already learned, it will be somewhat different from the Machine Shop drawing. Begin by laying down the center lines, and then, make a full size copy of the Machine Shop drawing. (Side view is sufficient.) If you use a shrinkage rule the shrinkage will be taken care of. Notice that the drawing calls for C. I. ; therefore you must select the cast iron, or y% per. foot shrink rule. Next examine the drawing and pick out the "f's." The surface which the "f" crosses must be finished or filed off in the machine shop. On these surfaces we must add y%" . This constitutes 48 In Wood Pattern Making J z / 49 rrr LJ_ / 5. 8 p3" ¥■ ■?- 7\1 + J P H* *-T? 4S h y CI — /i- rt.< w: In Wood Pattern Making 71 through the top piece and j4" into the bottom piece. Taper the ends of two dowel sticks and drive them in so that the taper just comes through the top piece. Bore screw holes (b Fig. 48) a little larger than the head of the screw you intend to use. You want the head to sink below the surface about J4" so that your tools don't strike it when turning. This is called counter boring. .Drill holes slightly larger than the smooth shank of the screw, as shown at h (Fig. 48). Drill no screw hole into the second block. Screw the blocks tightly together.* Punch the centers in the ends, being careful to get them exact. The center must be on the parting-. Drive in the spur center. Hold the piece in the vise for this opera^ tion, so that the point on the spur center does not force the blocks apart. Now turn the pattern up on the lathe, in the usual manner, until you have reached a point, as illustrated by Fig. 49. Then sandpaper and shellac the job once, and remove it from the lathe and with a bench hook and back saw, saw off the ends, take out screws, and return them to their proper box. Do not saw too near the core print, as you must now take a sharp chisel and chisel the ends smooth, being careful not to chisel off the draft which you should have turned on, as shown at draft, (Fig-. 49). Now finish the shellacing, painting the core print black and also the outline of the core on the parting of the drag half of the pattern. * Corrugated steel fasteners could be used ; but screwing blocks together is a more valuable exercise. J2 A High School Course The Core Box The cylindrical hole through the casting is formed by a horizontal core. The core must be moulded in a core box, which the pattern maker must furnish. To make it, fit and pin two blocks together. For this job, the blocks should each be roughly 8" X 4" X ij4". The pin holes should be bored through one block into the other and taper ended dowel pins fastened into one of the blocks, as was done in the pattern. When the blocks are pinned together, dress off one edge square with the joints and use this as a face edge for squaring the ends, which should next be dressed off. The length of the core box is always made a little less than the over-all length of the pattern, so that the moulder will have no difficulty in setting the core into the mould. Gage center lines on the joints and ends of the blocks, using the face edge as a guide. (See note, Fig. 50). With sharp dividers and using as cen- Loi/ out core 60^ m'M o Dowe/pm holes clean cut lines. Ce/rJer//he g&yec/ Porajfe/ fo face /Tcfye Fig. 50. Layout of Core Box In Wood Pattern Making 73 ters the intersections of the center lines with the joints, strike clean cut circles on the ends. Con- nect the circles with clean cut lines. All the wood so .*> 8 CO OSj 74 A High School Course within the circle must now be removed. Run several saw cuts from the joint to the circle and gouge out the wood with an inside ground gouge of suitable radius. To insure gouging the same diameter hole, all the way through, you must make tests with a straight edge, as shown (Fig. 51). When all the lumps are removed the straight edge will ride on the end circles. A templet, as shown, can also be used. CHAPTER IX GOUGE AND TEMPLET WORK Fig. j2. Drip Cup The The most convenient way to test the Templet depth and shape of the bottom of the drip cup, is to employ a templet. A templet is usually made of wood, about y%" thick, cut to desired shape and used to test irregular surfaces. 75 7 6 A High School Course DRIP CUP Instruction Card 1 . Plane a piece of wood to the thickness of the drip cup, but longer and wider. 2. Plane off one end, giving it some draft. 3. Lay off the outline of the cup on the face and ends. (Fig. 53.) Fig. 53. Layout of Drip Cup 4. Make a templet for testing the inside. (! 1 =7 I J _l Fig. 54. Templet for Inside 5. Gouge out the inside. Use an inside ground paring gouge of suitable radius, along the straight lines, and an outside ground or a In Wood Pattern Making 77 6. 7- spoon gouge, at the curved end. Clean out all lumps, until the templet can be slid along without riding on a lump, and cut deeply enough, so that the ears of the templet ride on the edges of the cup. To test the curved end, revolve the templet on the center of the curve. Sandpaper the inside perfectly smooth. Round off the bottom by planing down to the curves drawn on the ends. (Fig. 55.) Fig. 55> 8. Make a templet for rounding off the end. 9. Saw off the end to the curved line and work it to shape with a chisel or spoke shave, testing it frequently with the templet. To Fig. 56. Templet for Outside keep the vise from mashing the job during this operation, shape a block to fit the inside y8 A High School Course in order to get the pressure on the bottom instead of on the edges. 10. Make the strip which fits across the other end and nail and glue it fast. See that the draft is correct. In moulding this cup, the hollow is formed by a green sand core which hangs in the cope when the cope is lifted off. Built Up Work, Fillets, and Tail Prints Rail Up to this point, our patterns were of Stop such a nature that they were easily cut from one piece. In most cases, however, it is more economical to build the patterns of several pieces. To make the rail stop, get out two pieces y%" thick and the specified shape for the web, and pin them together (Parted Pattern). Then get out the pieces that form the base and the curved part, and glue and nail them fast on each side of the web. Fillets Examine any rough casting and you will find few sharp corners. Whenever possible corners are rounded. The reason for this is that, when iron cools, the crystals arrange themselves at right angles to the surface and, if a corner is left square, they join imperfectly at the corners; so sharp corners must be avoided. To save much carving, leather fillets have been devised which can be glued into the sharp corner. In Wood Pattern Making 79 8o A High School Course The leather fillet is a strip of leather of triangular cross section. To apply leather fillets, begin by cutting them to proper lengths, laying them flat upon a scrap piece of wood and applying glue. Allow the glue to dry, until it is very sticky, and then place them in the corners and rub them hard with a rounded brass rod or a fillet rubber. This presses out excess glue and gives them a round surface. O o Fig. 58. Fillet Rubber Tail The holes in the base must be cored. Prints An ordinary core print projecting from the base would not draw from the sand. To conquer this, run a tail from the print to the Fig. 59. Tail Prints In Wood Pattern Making 81 parting. This is called a tail print and must have a special box made for it. s< -\ ., <"l (\ \ !\ i! ii Fig. 60. Core Box for Tail Print CHAPTER X FACE PLATE WORK The Chuck The cylinder cover (Fig. 28) is or Face Plate a good example of face plate work. Find a three-inch face plate. Dress off one side of a board about 7" square and 1" thick. Lay off a j" diameter circle on the board, and saw to this circle, on the band saw, if the shop is equipped with one. Screw the 3" iron face plate fast to the true side of this disc at its center. Face the disc off true on the lathe. Use a y% round point tool for roughing, and a 1" square point tool for finishing. Don't use a gouge on patterns turned on a face plate. Test the sur- face with a straight edge. Bore three Y^" holes into the wooden disc equal distances apart and about 2j4" from the center. This constitutes a chuck or face plate upon which we will turn a cylinder cover like Fig. 28. Cylinder Prepare a disc about 6y 2 " diameter Cover and 1" thick. Screw it fast to the chuck with ij4" No. 14 screws, in- serted in the three holes in the face plate. In screwing work to a face plate, be sure to select screws which do not go all the way through the job, and put them at such places that your tool 82 In Wood Pattern Making 83 will not strike them when you turn deep portions of the job. Next turn down the edge to the proper diam- eter, using the spear point tool. Test with cali- pers. xzs: -/ X X • % Fig. 85 In Wood Pattern Making 109 y% strips inside. The narrower the strip the less to dress out. This box can be dressed out with a spoke shave, or round bottom plane of suitable radius. The core prints can be fastened on the end, and boards, nailed across the ends of the core print. (Fig. 86.) This half box is all that is necessary for such a job. The core maker rams the box up twice and pastes the two half cores together, to form a whole. This can be done with any symmetrical core. \l k\ ,\ . -i- 9X \ tt \ "VW \ V, Fig. 86. Core Box Loose Pieces Cylinder The cylinder cover, given in Fig. 87, Cover would be impossible to mould by any method so far considered, without a troublesome core box. By resorting to loose pieces, the operation is simplified. This pattern should be parted on the line "A-B." Both halves can be turned on a face plate. The round part "P" should be turned straight, and no A High School Course Fig. 8?. Cylinder Cover In Wood Pattern Making in the ears "E, E," set in, as shown in Fig. 88, but not permanently fastened. Fig. 88. Loose Pieces They are held in place by loose dowel pins, or large nails, slipped into holes bored through the ear into the pattern. The moulder rams up, until the loose pieces are covered with sand, when he digs into the sand and removes the pins. The loose pieces will then be held in place by the sand. When the ramming up is completed and the pattern drawn, the pieces remain in the sand. The moulder reaches down, and with a sharp point picks them out. Pupils finishing this course before the end of 112 A High School Course the year are prepared to build a set of patterns for a simple machine which could be designed in the drawing room. The foundry, forge and machine shops should co-operate in building the complete machine. Patterns for such machines may be substituted for the given exercises if they cover the same points. INDEX Arms, for wheel.... 96 Assembling- shop.... 4 Back saw 14 Battens 41 Bevel 16 Bit, auger, how to tell size 56 Bit, sharpening 12 Cone print 66 Calipers, inside 90 Calipers, outside .... 60 Castings 3 Center plate 106 Cheek 23 Chisel 16 Chisel, square point. . . 64 Chisel, turning ...... 59 Cope 23 Core 25 Core box 26 Core box, standard.. 102 Core prints 27 Core sand 26 Cores, balanced 27 Cores, dry sand 27 Cores, green sand ... 27 Cores, horizontal .... 27 Cores, vertical 27 Cupola 3 Designer, machine.... 2 Draft 32, 47 Draftsman, machine.. 2 Drag 23 Drawing, mechanical, shop 2, 44, 46 "Drawing Cut" .... 15, 16 Drawing, in moulding 25 Drawing, pattern maker's 47 Draw screw 25 Kiln, dry 40 "f" 46,48 Face edge 17 Face plate, wood.... 82 Face side 17 Fillets 78 Fill up pieces 42 Finish, an allowance on patterns 45 Finish, in machine shop 3 Flask 22 Forge shop 4 Foundry 2 Foundryman 3 Gases, in a mould.... 25 Gage 13 Gate 25 Gouge, roughing .... 58 Holes, under %" 56 Instruction card 17 Knowledge a pattern maker must pos- sess 78 Loose pieces in Lumber 39 Machine shop 3 Manufacturing plant. . 4 Mould 2,20 Mould board 23 Moulder 2 Moulding sand 22 Moulds, loam 20 Moulds, dry sand.... 21 Moulds, green sand.. 21 Open joints 4 Parting, moulder cuts a 34 Pattern making, definition of ... . 39 Pattern 2, 23 Patterns, parted .... 33 Pinch dogs 107 Plane, blocks 15 Plane, fore, jack and smoothing 10 Pouring 25 Print, cone 27 Rammer 23 Rapping 25 Re-chucking 84 Rule, shrinkage 32 Scribe 14 Seasoning lumber.... 40 Segments 84 Sharpening lathe tools 61 Sharpening paring tools 12 Shellac 52 Shellac, applying it to turned work. . 68 Shrinkage of metals.. 31 Shrinkage, an allow- ance in patterns. . 47 Shrinkage rule 32 Slicker 24 Spear point tool 83 Sprue . 25 Sprue pin 23 Staves 104 Swab 25 Tail prints 80 Templets 75 Trowel 24 Try square 13 Tumbling barrel 3 Vents 25 Vent wire 25 Wheels 96 Wood turning 57 Wood working exer- cise 17 Working to a line... 14 Wrought iron 4