CHAPTER XVII.

MACHINE TOOLS FOR PATTERN MAKING.

Pattern making being a process for originating, it is obvious that the use of special tools in the same is out of the question; and there is at the present day no branch of woodworking in which power-driven tools or machines are so little used as in pattern making. In some pattern shops a lathe only is to be found; in a great many a lathe and jig-saw complete the complement. The lathes are in a majority of cases of simple, if not crude, construction, without any slide rest or self-acting feed motions- those shown in Figs. 45 and 55 being a fair representation. It must be conceded that from the desultory nature of pattern work and the fineness of finish required, hand work possesses many advantages, because in so many cases the work can be done by hand in about as much time as it would take to set a machine for the purpose. Furthermore, a hand plane can be sharpened on an oilstone in less time than it would take to stop a machine and take the planing cutter out. A pattern, when commenced, is worked upon by the workman or workmen until finished; and in any case each man does his own marking out, sawing, planing, boring, turning, etc.; and as each job must be, in the main, done in certain order, no part of his work can well—as a general rule-wait until a machine is unoccupied. Notwithstanding all this, however, there is no doubt that much work is done by hand that could be advantageously done in a machine, providing the latter does not occupy too much shop space, is not too heavy, is designed to perform several operations, and to be set for either of them readily and easily. As an example, core boxes and the segments for building up cylinders, etc., may be noted. A

well constructed lathe device would bore a core box in a fraction of the time it requires by hand. A pattern maker's lathe having a friction straight and cross feed, and very light parts, would be a desirable tool, because of the facility with which facing up work and cutting out core boxes could be done. In facing up work, a large porportion of the time is spent in testing the straightness of the face. Core boxes could be bored out rapidly by fastening them to the light lathe saddle by a handy fixture designed for the purpose the cutter being adjustable in a bar revolved between the lathe centers.

Of the few power tools or machines designed for pattern makers' use, a few of noteworthy examples are shown in the following engravings:

In Fig. 236 is shown a pattern maker's face lathe. The hand rest, it will be noted, is supported by an arm pivoted at one end, and supported by a leg at the other end, so that it can be adjusted to suit the work.

The reason for making the cone pulley of wood is, that its momentum when in motion being less than if of iron, it will stop and start more quickly; and this is a valuable consideration, when the lathe requires to be so often stopped and started, to try the work. The box frame is provided to prevent the excessive vibration to which lathes, supported upon legs, are subject under high speed.

In Fig. 237 is shown a smaller face lathe for turning hubs, bosses, core prints, and similar work, than can be done without the use of a back center.

In Fig. 238 is represented a lathe head and tailstock for mounting on either wooden or iron shears, as may be preferred. Iron shears keep more true, and the tailstock is more easily moved and kept in line or set over, as the case may be; the only objection to them being that they are apt to damage the edges of tools carelessly laid down; and wood may be made of large proportions, to avoid tremor

where lathe shears and legs are used, as in this class of lathe.

It will be noted that each end of the cone spindle is provided with a face plate. The extra one is for use upon

47 becomes necessary. This provision is very handy, but is not so good as the large face lathe shown in Fig. 236.

Next to a lathe, a jig saw is the power tool most commonly found in a pattern shop. It is indeed a very useful tool to the pattern maker, notwithstanding the noise and

jar that usually attends its use. Its small expense and lightness, as compared to a band saw, are no doubt the con

Fig. 239.

ATLANTIC WORKS
PHILADELPHIA

siderations which cause it to be preferred, because the band saw is an infinitely superior machine, except it be in cases where an area surrounded by solid wood requires to be cut out, in which case the jig saw can be detached, passed through the work, and attached againthus performing a duty peculiar to itself. In the jig saw, shown in Figs. 239 and 240, the table is planed true and pivoted, so as to cant over, for sawing bevels, or to give the pattern the necessary draught. The crank is provided with a conical schiele bearing at the front, adjusted by nuts at the end of the shaft. To stop the saw instantly, a friction brake is provided, and the sliding head or stock is adjustable in a long planed bearing upon the front of the column. The top guides are adjustable vertically, to suit

different lengths of saws, and pivoted to regulate the