Turning Large Diameter, Short Length Material

[Shiseiji]

I've had luck with center drilling the center on the drill press, then placing two sided heavy duty tape on the faces of the 4jaw (note on the face of the jaw itself) adjusting so that the jaws are smaller than the desired diameter. Pinching the stock between a live center and the jaw faces. And frequently monitoring to ensure nothing is getting loose.

Daryl
MN

Daryl, what rpm are you using with this?

Thanks,

Ron

 

[Uglydog]

I have no recollection what I used.
Not really any different than turning with a dog/dog plate.
I'm guessing I did the standard calculations.
Make sure your live center is tight. Again... not really any different from a dog set up.
I think last time I did this I used two sided white foam tape. Was fairly dense foam.
I liked watching the foam squish and felt better about knowing I had equal contact.

Daryl
MN

 

[markba633csi]

Fasten the piece to another smaller piece using some type of adhesive- I've used small dabs of crazy glue but contact cement may work also.
Take light cuts, then heat and crack the part free and clean up the glue remnants with a razor blade or x-acto knife
Don't use so much glue you can't get it apart is the main idea here- just enough to get the job done
-Mark

 

[hman]

One technique I've used with some success: Tightly grab a piece of wood, a bit thicker than the height of the jaws, in the 3-jaw (stacked/glued hole saw off-cuts are handy for this). Use a sharp lathe tool to face the outside surface flat and true. Then apply several strips of double-stick tape (the thin stuff, not the foam) to the wood. Hold the (center drilled) workpiece tightly against the wood with a live center in the tailstock.

The wood provides a larger support and sticky-drive surface than the just the ends of the jaws. But light cuts are still required. After the job is done, save the wood plug for re-use. Give it fresh a skim cut if needed.

 

[Shiseiji]

Again thanks everyone. Didn't get to it today, tomorrow I hope. I have the worst luck with super glue, even professional name stuff. Seems it only likes my fingers. And I've tried acetone, alcohol, and MEK to clean surfaces . . .

Ron

 

[SLK001]

Get some carpet tape from HD, or other. It's a thin, double sided tape. It's got a monster grip.

 

[mmcmdl]

I made up carbide pressure pads that mount in my chuck jaw threads . These are serrated carbide pads soldered onto bolts . Live center in the tailstock with another pad and you're good to go . The pads have never slipped even on some very large lathes .

 

[Shiseiji]

I made up carbide pressure pads that mount in my chuck jaw threads . These are serrated carbide pads soldered onto bolts . Live center in the tailstock with another pad and you're good to go . The pads have never slipped even on some very large lathes .

Sorry, my imagination is failing me. "mount in my chuck jaw threads" ? Sounds interesting, just can't visualize it.

 

[Illinoyance]

Face both sides. Centerdrill one side. Using a live center in the tailstock push the part hard against the chuck jaws. That will give enough friction to take light cuts on the OD.

 

[Shiseiji]

Face both sides. Centerdrill one side. Using a live center in the tailstock push the part hard against the chuck jaws. That will give enough friction to take light cuts on the OD.

Ah, got it, thanks. Came close to that idea, was trying to center in the 4 jaw "close enough" with pressure from the tailstock with zero luck.