B. R. Wicks

A small emery wheel about your workshop, house or barn can be made to do a large amount of useful work, such as grinding knives, shears, axes, chisels, plane irons, spoke shave irons, etc., and to the amateur mechanic a tool of this kind will be found to be one of the most useful to be found in his workshop, as it can be used for grinding off uneven places on castings when good files would be spoiled; also for grinding lathe tools, drills, counter bores, reames, cutters, and a hundred other uses that present themselves in the course of his work from time to time. No amateur who is engaged in making models of steam or gas engines, electric motors or dynamos, can afford to be without one, as the time expended in making it will pay for itself a hundred times over.

The grinder to be described is a six-inch bench grinder, equipped with all the handy fixings to be found in a modern machine. This grinder can be operated by foot power to very good advantage, or by a countreshaft when motive power is to be had. This grinder is composed of five iron castings: one frame, A; one driving pulley, C; two wheel flanges, D and one tool rest, H. The spindle B, rest No. 1, 2 F", No. 2 F, and tool rest spindle G, are made from steel. The set screws are all standard thread and are cut off to figures given on detail drawing and 5/32 in. rods driven through the heads. The two construction drawings show the parts of this grinder in their respective places, and the details below show the parts that are required to construct the grinder, with dimensions and name of parts and material used from which to make them.

In beginning the tooling on the castings the frame or stand, A, will first be dealt with. First find the centre of the 1/2 in. boss of the bearing barrel with a pair of hermaphrodite calipers, and make a light prick punch when the centre has been located. Rub the bottom of the casting with chalk, and set the castings on a surface plate. Set the bearing square both ways with a square, and the needle of the surface gauge or scratch block exactly in the centre of the prick punch mark in the 1/2 in. boss, and strike a line across the bottom of the casting ; this will give one centre line. To find the other centre, set the casting square with the inside of the base and set the gauge needle as before to the prick punch mark and strike another line across the bottom which will give the exact centre of the casting both ways. Centre both the boss and bottom with a small drill, and countersink and face off the bottom of the casting between centres.

The 9/16 in. hole for the spindle, B, is now to be drilled and reamed. This operation can be done to very good advantage between centres in the lathe. Find the exact centre of the bearing barrel on each end with the hermaphrodite calipers make a fair size centre punch mark. Put a 5/32 in. drill in the drill chuck, and with the tail stock centre in one punch mark, start the drill in the other punch mark. Drill in, feeding the drill slowly to a depth of about 1 3/8 in. Turn the casting around, end for end, and drill in until the two holes meet. With care in drilling these holes will come exactly in line. Remove the 5/32 in. drill from the chuck, and in its place use a 1/2 in. twist drill and drill as before. Then put through a 17/32 in. drill and drill all the way through, reaming out with a lathe reamer about .002 smaller than 9/16 in. and finish with a 3/16 in. hand reamer.

Facing the two ends of the bearing can be done with a countrebore large enough to sweep 1 1/16 in. and provided with a 9/16 pilot, or if the lathe will swing 8 inches a 9/169 mandrel can be forced in and the ends faced off in the lathe. The length of the spindle bearing is 2 1/2 in. The 1 1/8 in. boss on the front of the casting forms a bearing for the rest No. 1, E.

6-Inch Bench Grinder