machineman wrote:
I think accuracy may be the root of some of these. Check out this site

http://easyweb.easynet.co.uk/~chrish/worms.htm

Yeah, that's one of the sites that shows a *hob-driven* blank.
Actually, I didn't see any sites with independently driven blanks.
Googling "synchronized gear hobbing" wasn't much help (production /
machinery sites mostly). Does anybody have a good link for synchronized
gear hobbing?

Bob