Cole jaws 3/8 to small.... [expletive]!

[Brian Greb]

Hey guys I'm working on turning a ring I have one side and the outer edge done. Now I just need to turn the inside edge of the bottom. No problem I thought "I'll just grip it in the old Cole jaws"... well I have the mini cole jaws on a SN2 chuck so its 6.65max diameter just wont grip my 7" ring. Is there an easy way to expand its capability? Is the a simple alternate solution that I'm missing? Or should I just brake-down and go buy the larger cole jaws?

I have a looming deadline so I gotta find a quick solution.

Thanks

[Tim Rinehart]

Don't go crazy with this, but to give a little extra width, build up an adapter to mount to the cole jaws with another inch or so of margin.

[Steve Schlumpf]

I agree with Tim - use wood to make some adapters to extend the jaw sizes to something you can use. Pay attention to the swing on your lathe - build them just long enough to get this job done.

[John Keeton]

Brian, I am not sure I understand the shape of the piece you are doing, but is it possible to use a faceplate, a piece of mdf, and turn a friction fit recess for the piece. A few pieces of tape should make sure it stays in place at a reasonable speed.

I may be misunderstanding the form.

[Tim Rinehart]

Brian,
One more thing on the little adapters. You'll want to mount them so that you can apply some closing force to the cole jaws, effectively holding all 4 of the adapter pieces firmly together.
Once you've done that, you can clean up the inside seating and gripping surfaces with your lathe, before mounting your piece.

By the way...this is essentially the same thing done with "Flat Jaws" you can buy for most chucks. I have them for my Stronghold. The biggest difference, is that the aluminum chuck jaws (cole's) are not as beefy as the steel flat jaws, which is why both Steve and I said to apply some moderation to use of this technique.

Good luck...can't wait to see the piece!

[Tim Rinehart]

Brian, I am not sure I understand the shape of the piece you are doing, but is it possible to use a faceplate, a piece of mdf, and turn a friction fit recess for the piece. A few pieces of tape should make sure it stays in place at a reasonable speed.

I may be misunderstanding the form.

Thanks for reminding us that before cole jaws became such an obvious tool...most turners would have relied on jam chucks that are sized to hold the piece well.

Brian, one thing that can't be overemphasized...and I'm glad that Cindy Drozda reinforces it in her DVD I saw recently...is the use of tape.
I use it whenever I want a little extra insurance...cheap too.

[Brian Greb]

Brian, I am not sure I understand the shape of the piece you are doing, but is it possible to use a faceplate, a piece of mdf, and turn a friction fit recess for the piece. A few pieces of tape should make sure it stays in place at a reasonable speed.

I may be misunderstanding the form.

Here are some pics to make it clear as mud... but a jam plate may work.

[Brian Greb]

When I read the post about taping the piece into the jam chuck a light went on in my head. I thought "why don't I replace the rubber pieces with tape". As I went to do this I had another idea... Plastic hose. So I lopped off 8 pieces of plastic tube I had laying around and substituted those for the grey rubber pieces... presto 3/8" bigger grip.

Thanks for the help guys... I post the finished piece when it is done.




Here's a pic of the mod

[John Keeton]

Brian, now you have me really pondering what you are creating!! I definitely need to see the finished piece! Glad the Cole jaw idea worked. Just a couple weeks ago, I just used pieces of clear tubing and longer bolts to extend the depth of my Cole jaws - worked great!