easily transferred to the strawboard by the use of a sheet of carbon paper and it is then a simple matter to cut out and glue the duplicates together to get the projection wanted. In this way inscriptions, figures, and ornaments in basrelief, that would not be possible for the unskilled worker o model in clay, can be reproduced in concrete, in perfect outline, in the easiest manner conceivable. CHAPTER XII A SIMPLE LATHE FOR TURNING SAND MOLDS, PATTERNS, AND CORES IN producing a number of sand molds of the same design of such simple outline as to permit their being fashioned by the aid of a template, the use of a lathe will make the work far more rapid as well as less laborious, and in a plant producing concrete work from sand molds on a commercial scale will be found invaluable, as the mold is turned in a moment's time; even quicker than the pattern can be placed in the usual manner of making mold. The lathe illustrated is very simply made and while it will do the work successfully, can doubtless be improved upon, where such a tool is in every-day use and must be built more durable. The framework is built of 2x4" pieces to which is attached the treadle and wheel, to furnish the drive to the shaft by the means of a belt and pulley, as shown in Fig. 10, in which space forbids the illustration of more than the upper portion of the machine. The bed of the lathe is made of a 2x10" plank and at the end the pulley is attached, a standard is erected perpendicularly, that is 24′′ in height; this can be made from a plank with a slot or bearing for the shaft to turn in and is placed high enough from the bed of lathe to permit the average size of flask to be manipulated beneath same. The second standard is placed about four feet from the one at the drive end of lathe as this will permit the average size of work to be turned between same. The second standard is placed about two feet from the end of machine so that a template may be attached to the end of shaft for cutting out many styles of molds, as shown in drawing. The template between standards is bolted to the shaft by clips, as illustrated, and the edges of template has a cutting edge of metal which is bolted to the wood part of template on opposite sides, so that the sand cut from the mold will be thrown away from the worker operating the lathe. Guide boards should be erected upon the bed of the lathe so to permit the placing of the flask in the exact position you wish same, as well as a guide to holding it in that position. With heavy molds this will be difficult, so a separate table should be made to go upon the bed of lathe; this is made the size of the largest molds to be turned so that it will support them perfectly; to raise and lower this table evenly, two screws as used for wood vises can be placed underneath same so that the simple turning of the handle or wheel to screw will raise the table exactly and with ease. The template is adjusted to the shaft, in the manner shown for the template of urn in illustration, and the flask filled with sand placed upon the table; the shaft is now revolved at high speed and the table and flask raised with the screws gradually, so the lowest cutting edge of template just strikes the sand, cutting it out in the shape of template and throwing it away from operator; as fast as the mold is cut the table can be raised until the one-half of design is complete or the flask touches the shaft. In making the template it |