Quote Originally Posted by Neale View Post
Trouble is, tooth needs to scale with distance along - tooth width and gap aren't constant. There are some standard ways of getting close using a dividing head and taking three cuts per tooth space but I'm not sure how you would fully automate that.
Yeah, you need to take the standard form, then scale it to/from the disappearing point where the centre of the two shafts meets.
As Leadhead isn't hobbing, the variable tooth size doesn't really add to the complexity of the machining, just the designing.

Gear machining is something that fascinates me, especially when you see some of the setups and tools from pre-computer days.