Thread: Helical milling

I need some logic checked here -
My mill has a metric lead screw and at the moment I'm making up gears so that I can connect a universal dividing head up and cut helical parts (gears etc).
If I'm cutting metric based parts I shouldn't have a problem (well, no more than the usual number) but if I'm trying to cut inch based gears (diametric pitch system), I think that will need a 125/127 tooth combination gear to translate metric leadscrew movement to imperial lead screw movement.
Does that sound right? Anyone else doing this sort of thing?

Michael

I havent cut any Helical gears,but I dont think you will need to worry about gearing to change your leadscrew from Metric/Imperial.
From my understanding the only Metric/Imperial part of the job in play is the Cutter,wether that be DP or Module,and the OD of the gear and the lead of the gear.
All the rest of the adjustments are done through the change gears,dividing head ratio and angular offset of the mill table.