| Fig. 1 shows a lens grinder, suitable for the amateur for making lenses up to 1" diameter. It is also useful to those interested in grinding and polishing minerals and stones into cabochon gems for rings and other jewelry.
Formed laps may be cut directly on the machine with a hand tool. Any motor from 1/10 HP up may be used. The motor pulley should be 1 1/2" and a 3/8" vee belt should be used. Get them from Sears Roebuck or a hardware store. The grinder should be oiled frequently.
| It is important that the lens should be the same thickness all around the edge. If grinding is continued until the convex surface cuts the flat one in a sharp edge as in Fig. 5A or if car is taken to keep the edge even in as in Fig. 5B, no centering will be necessary.
During the fine grinding you should test the lap occasionally with the template. If it wars out of shape swing up the tool rest and reform it.