W&K,
I have made wheels from Lexan, Delrin and Acrylic. Lexan and Acrylic are very similar in machining and in performance. The Delrin is great to machine but is a heavier material so a set of wheels the same size the Delrin was always slower. Delrin I used carbide tools and with the Lexan and Acrylic I went with a HSS tool.
Ian