Boring UHMW Polyethylene

I mentioned yesterday the struggle that I was having boring UHMW polyethylene--very slow process. Today I was making parts to put casters under a Synta EQ6 telescope mount--and while the bore is much smaller (only 1.75" diameter), I was using Delrin today--and it was much faster. Delrin is actually a somewhat more rigid and harder plastic, but I'm told that it is a form of polymerized formaldehyde, and during the cutting process, some of it turns back to liquid state, making it a self-lubricating plastic.

The Delrin is about three times as expensive as UHMW polyethylene--but the labor difference alone justifies spending the extra money for the Delrin.