Posted by Bill S. on August 06, 2002 at 19:53:51:
In Reply to: Fellows stub tooth posted by Charlie on August 01, 2002 at 12:00:38:
Hi Charlie,
For example, in a Fellows 10/12 stub tooth, 10 defines circular pitch, pitch dia., and tooth thickness just as for a standard 10 pitch gear. The second number (12) defines the addendum and dedendum just as for a 12 pitch gear.
Pressure angle is always 20 deg, and the clearance is 0.25 / the denominator (12).
By the way, Fellows came up with this system in 1898, according to my sources.