Emmerich Manual High School - Ivian Yearbook (Indianapolis, IN)

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24 MIND AND HAND. PATTERN MAKING. ©NE of the most interesting and in- structive studies m the technical de- partment is that of pattern making. The patterns made in this department are generally of pine or cherry. They are used by the foundry class in making cast- ings required in the machine room. The first patterns in Course I. are not very difficult. They are given merely as exercises to make the student more famil- iar with the handling of his tools and the problems of draft, finish and coring. In solving these problems, he must know how the pattern is to be molded, whether in a two or three part flask. He then adds the draft accordingly, so that the pattern may be easily drawn from the sand. There is no set rule for the al- lowance for draft, but is generally about one-thirty-second of an inch increase in width to one inch in height. Finish is an allowance added when the castings are to be filed, planed or turned. The allowance for finish is about one-six- teenth of an inch, but varies with the size and shape of the casting. The shrinkage of iron is about one-eighth of an inch to the foot, and must be figured out for each pat- tern. For convenence, a pattern maker ' s or ' ' shrink rule may be used. He must also know whether a green or dry sand core is required. It the former is needed, he must leave a hole in the pattern corresponding to the core; but if a dry sand core is wanted, he adds core prints to the pattern where the hole should be. These core prints leave impressions in the sand in which the core rests. The core-boxes, in which the cores are made, are sometimes more difficult to make than the pattern. They are usually made of several pieces glued together, a joint being made for each change in the diame- ter of the core. The shape of the core corresponds to the cavity in the casting. In making such patterns as pulleys, live cones, etc., the warping of the wood must be taken into consideraion. The patterns could be made from one piece, but after being used several times in the damp sand they might warp so much that they could not be used again. Wood shrinks most across the grain, and to prevent this the pattern is built up, that is, made of several layers. Each layer consists of six, eight or any convenient number of pieces. These pieces are cut and glued so that the grain of the wood practically runs with the cir- cumference of the pattern. The patterns in the latter part of Course I. become more practical and difficult than in the beginning, but in Course II. they are still more complex. The boys in the advance class are at present making pat- terns for a wood lathe which is to be used in the shop. Each boy is required to make a complete sketch of his pattern before he can proceed to work upon it. These drawings, requir- ing much study and time, are, undoubtedly, very good practice. Chas. Cabalzer. THE FOUNDRY. THE foundry is a well lighted room, con- taining in one part two rows of benches, which give working space and hold the apparatus for some twenty one pupils, and in the other is the cupola, core- oven and pouring floor. The work done here requires one year, and this conveniently divided into the first and second terms. During the first term the beginner is made acquainted with the manner and uses of a moulder ' s tools. He learns how to make, and is given time to become fairly pro- ficient in the various kinds of moulds which

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MIND AND HAND. 23 ing it. Several lathe tools then are forged for the machine-shop. Each boy is allowed to make something to tike home. This generally takes the form of fish gig or anchor. The practice obtained in making these is excellent, as it requires accuracy of judgment and a care- ful manipulation of the hammer to form the slender prongs and barbs. Lastly, the class is put to work on some project work for the schools. At the be- ginning of the last term a fence was de- signed to 2:0 around the east side of the building. That class made four sections of fence, and the present class will make as many. The class is divided up into four sections, each section to make a length of fence. In this way much more is accom- plished than otherwise. Thus it will be seen that the work is all FORGE ROOM. very practical, and in the shop it is carried on in the most practical manner. It is not, however, our object to turn out black - smiths, carpenters or machinists. The work is arranged and presented so as to give the boy an idea of what the work is like, to show him how to use his hands, and to co-operate with the work in the •classes. It is undoubtedly true that a man who knows how to drive a nail straight, or how to use a lathe, has the most advantages in the world, for the accuracy required and the finish necessary on a piece of work gives him advantage, when taken together with the other branches, which the man has not who knows nothing of these things. Harry P. Mc Canst, 12 B Grade.

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MIND AND HAND. 25 I W2 B.Bur[ord I lndpla,Jnd. PATTERNS FOR WOODWORKING LATHE, MADE BY STUDENTS IN THE COURSE IN PATTERN MAKING. ROUGH CASTINGS FOR WOODWORKING LATHE, MADE BY STUDENTS IN THE COURSE IN FOUNDRY.