I recently made some cole jaws from 1/2" hardwood plywood based on posted suggestions here as well as the Darrell Feltmate's website and the Mark Kauder article onWood Central website (links below). I made these for my Nova Chuck and a Jet 1442 lathe and I've already used them at least three times. It was very straightforward, but I have a few tips for anyone who plans to try it:
- At some point while you're marking out the jaws, but before you cut them into quarters, number them 1 through 4 corresponding to how they'll be mounted on the chuck so that you can always mount them in the correct order and chuck slide. Theoretically it shouldn't matter, but in reality it does.
- For the hold downs/bumpers, I went with rubber instead of wood--it expands and contracts as a function of bolt tightness, giving me a bit of tunability for out-of-round pieces. I used rubber cone washers used for toilet plumbing repair--outstanding! The rubber is non-marring, they come in a variety of sizes, and they already have a hole in the middle.
- I wasted a huge amount of time trying to track down longer metric flathead machine screws locally and ultimately went with an online source: the Bolt Depot--link below. The screws that came with the 50mm Nova jaws are hexhead 6mm (1.0 pitch) by about 3/8" long (just the threaded part only) by my measure. I'm using 6mm x 16mm phillips flathead screws for the homemade Cole Jaws with holes countersunk into the plywood such that the screw tops are about 1/8" below the plywood surface. I also ordered 6mm x
formatting link
for the longer metric machine screws I used:
formatting link