# Modifying Nova Chucks Jaws



## Mike Mills (Mar 14, 2012)

I have been wanting to modify a set of 35mm bowl jaws to accept a larger spigot. For those not familiar with Nova jaws, the pin jaws, 25mm bowl, and 35mm bowl all have a spigot opening of 3/8”. My current idea is to use a 3/4” bit and drill it out on the lathe; the jaws are 3/4” thick and of course would have a 3/8” pilot hole. Do you see any problem with drilling them out? Fast or slow lathe speed? I will use a slow feed rate and cutting fluid.
I did check and the jaws are not hardened; the opening of the chuck body is one inch.
Thanks


----------



## Mike Mills (Mar 15, 2012)

Roy I checked all over and they do not make other jaws. The closest is the 35mm spigot jaws which close down to about 1-1/2”. That leave a gap of ½” between other jaw sets (the largest spigot for those is 1”).

Guess I turn up some split bushings for the couple of sizes in between.

I checked and the ¾” bit is just a tad too large without getting into the jaw slides, maybe 1mm. I did ask the service center and the jaws are not hardened and can be machined.
Thanks for the replies.


----------

