I've some rollers of a rubbery or nylon consistency that came out of an old printer and I wished to cut a slot in them.
(Originally used as part of the paper-feed mechanism)
Trouble is, as soon as I apply any cutting force (Knife, saw, drill, milling cutter) they distort out of the way and very little cut results.
I tried using a Dremel-style grinder with some limited effect, but most of what resulted was obnoxious chemical fumes from the heat generated.
Application? Sliced in half lengthways they'd form a pair of fairly cheap dumb buffers for 5" gauge rolling stock.