Mill Gear cuttingg Arbors

[EarlH]

I need to make a 20 tooth gear for the fine feed option for my Heavy 10 lathe. I have the cutter, the mill and the dividing head. What I don't have is an arbor to hold the gear for cutting. I intend to make one. My question is How much taper should be there be in an arbor that will hold a gear with a half inch hole ?

Thanks,
Earl

 

[Tony Wells]

I usually just duplicate the fit the gear will have on the shaft you are making it for, or just a bit tighter. I don't taper the mandrel. There are ways to split the mandrel near the end and drive a set screw into a tapped hole, and a nut and washer on the outside to hold the blank very tightly centered. It's a bit hard to explain, and not that easy to pull off. You might want to consider a way to key the blank to the mandrel, so you don't end up slipping and getting a timing error in you gear.