Sunday, August 2, 2015

Machining Acetal vs. Aluminum

I mentioned a few days ago problems squaring an acetal rod.  Thanks for the suggestions.  The core problem is that acetal is very slippery, and a piece that is long and thin slips out of the chuck with little encouragement.  I have previously turned 2" and larger diameter acetal without difficulty, because there is more area to grab the acetal with in the jaws.  I am able to square and turn aluminum much more easily, because it is not so slippery.  Still, I find myself thinking a chuck with longer or larger area jaws would work better.


  1. A couple thoughts on possible fixes:

    Do you have spare jaws for the chuck? Consider scoring or roughing the surfaces, or even machining a matching radius.

    Can you find a thin wall tube, either steel, aluminum, or plastic, with a closely matching ID to the part? Rough up the interior, slit it, then use it as an adapter. Locate the slit between jaws. A small hose clamp just beyond the jaws might help keep it compressed, if you have the space.