On Oct 24, 9:21*am, "Karl Townsend"
wrote:
I need to make some new idler wheels for my wire EDM. The material is a very
hard black plastic. Maybe the same stuff you see on a car electrical
distributor. It needs to be non-conductive and be able to have a light press
fit for a ball bearing.

Can somebody give me a material name and source to order?

Karl

I sell various forms of plastic offcuts on ebay.

From what you and the others say, I would agree that white delrin or
phenolic is the way to go, but you could also have a look at unfilled
Nylon in the natural form. It's quite a hard plastic and it wears
very well. I think you'll find the black delrin or the black nylon
both have carbon black in them - it's the usual way they manage to get
a black colour.

If you want to have a look at some pieces, there are pictures at;

http://stores.ebay.ca/The-Great-Indu...eNameZl2QQtZkm


If heat is a problem, delrin softens at a pretty low temperature
( say, around 300 F) - nylon's a bit more tolerant. Delrin is far
more slippery, and is known for its insulating qualities in white as
well as it's ability to be machined to extremely close tolerances.

Eric