How to dial in part in 4-jaw chuck that doesn't protrude jaws

[Suzuki4evr]

UHMW (ultra high molecular weight polyethylene) is an extremely tough plastic with high abrasion and wear resistance.

How does this compare to delrin and is it more expensive?

 

[Doug Gray]

or if your centre hole from the arbor is true face a piece of scrap and crazy glue your disc to it. Use a centre in the tailstock to align.

 

[Jimsehr]

or if your centre hole from the arbor is true face a piece of scrap and crazy glue your disc to it. Use a centre in the tailstock to align.

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As a old school machinist I would not try to indicate the part. I would load part in 4 jaw then indicate the inside of the jaws them selfs at the 4 points where jaws come into contact with part. If 4 points are true then parts are true.
Jim Sehr

 

[Gaffer]

How does this compare to delrin and is it more expensive?

I'm no expert when it comes to plastics, but Delrin is a little more expensive. I've only played with Delrin, but plan to try UHMW the next time I have a project for plastic. I wish I could be more helpful.

 

[JimDawson]

Hi Jim.
I agree with all you said. I am going a bit off topic,but what does that abbreviation UHMW stand for? Is it like delrin or something of teflon?

Michael

Ultra High Molecular Weight polyethylene. Normally much less expensive than teflon or Delrin

 

[MrWhoopee]

How does this compare to delrin and is it more expensive?

UHMW is softer and less rigid than delrin and produces very stringy, tough chips. It requires sharp cutting tools and is prone to pushing out of the way instead of cutting, making it nearly impossible to hold close tolerances. It is very abrasion resistant and has a high coefficient of thermal expansion. Sometimes called "poor man's Teflon".

 

[Alcap]

This is what I would do If you have a faceplate, put something behind it like a aluminum plate with a 10mm hole , use a threaded rod through the spindle , indicate your disc , put some clamps then remove the threaded rod

 

[SLK001]

You should have left it on the arbor. For example, bore the ID to size, press in an arbor (make one if you don't have the correct size), put the arbor in your 4-jaw and dial in the arbor. To get the part far enough away from the jaws of your chuck, put another disk between your part and the chuck, then turn the outside.