Gauge for Laying Out Model Gear Wheels
The Gauge Steps Off Each Tooth Accurately for the Saw to Cut the Next Slot
The illustration shows a simple device for making small gear wheels by hand. It is made of a piece of brass, ¹⁄₈ in. thick and about 5 in. long, shaped as shown, forming a tooth, A, according to the size of the teeth required in the gear wheel, with the end B on a radial line from the center of the wheel. Use one or more hacksaws, according to the size of the slots or teeth to be cut. If one blade is not large enough and two are too large, grind off the teeth on the inner side of the saws, or if two are not large enough, place a thin piece of paper or metal between them to make the thickness required. Make a clamp, C, for holding the blades together, by using a piece of sheet brass, 6 in. long and ¹⁄₂ in. wide. This clamp also acts as a depth gauge for the slots.
Place the wheel in a vise and proceed by cutting the first slot very carefully. Place the tooth A of the gauge in this first slot and cut the next by holding the side of the saw close up against the end of the gauge, at B. This keeps all the teeth radiating from the center of the wheel. Cut each slot in the same manner until all of them are formed.—Contributed by George Jupp, New York City.