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:

1. 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.

2. 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.

3. 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
20mm screws hoping I could use them to mount the 50mm jaws on top of the
Cole Jaws, however the heads are just slightly larger than the countersunk
holes in the 50mm jaws and thus can't be used with filing off some material,
which I haven't bothered with yet. Maybe someone knows a better source with
more compatible screws.


http://www.woodcentral.com/cgi-bin/r...cles_123.shtml
http://www.aroundthewoods.com/jaws.shtml

Source for the longer metric machine screws I used:
http://www.boltdepot.com/metric-machine-screws.aspx