Andy, I'm going to try for a sinusoid with at least six peaks. The hobb idea is probably the better way to go for involute gears as only the single point tool is needed ground to the pressure angle. I was thinking about threading with this method to get a lobbed thread, you're thinking ahead. With clock (cycloidal) wheels , they can be hobbed but you need a different hobb for each module and tooth to pinion leaf ratio. Most of the time we are using single wheel cutters per module which is an approximation , so it will be feasible to make a form relieved single gang cutter using the eoffsets per angle as in what we're doing here.
I just found a 40:1 worm drive reduction gearbox in the workshop (2 actually and they could be coupled) , I'll next look at a way of coupling it to the lathe headstock spindle. I'll probably drive it with an auxiliary motor.
It's all very promising.
