"Snag" wrote in message news:sro3gg$r94$1...@dont-email.me...
Law's book describes a simplified method for grinding a cutter with circular
instead of involute curves. For another use I ground a concave circular
cutting edge on a lathe bit with a conical stone in a die grinder.
I made two gear cutters using a jig that aligns the lathe bit radial and
centered on the tooth gap, and repeatedly grinding down the visible contact
spots. It worked, but not particularly well because bluing wouldn't stick to
the smooth hard surface. I didn't think to try candle smoke. Both were
oddballs, one a 30 degree ANSI spline hydraulic pump shaft and the other the
cast iron steering sector on a Roper tractor.
I used the closest-fitting commercial gear cutter I have to rough out the
gaps in the blank, because cutting with a single flycutter bit is very slow
and wears the tool. You could rough out the gaps with the partly formed bit
and finish them after grinding it correctly.