Routing acrylic, cast vs. extruded

[Phil Thien]

I have some acrylic and I have no idea if it was cast or extruded.

I want to machine it on my CNC router. I've seen reports of extruded acrylic being problematic for some sorts of work.

Can I machine extruded acrylic with a router okay?

Is there a way to tell one from the other? Someone told me extruded usually has a plastic film covering, and that cast typically comes protected with paper. Is that a good indicator?

[Jerome Stanek]

Yes you can When I have to route extruded I use a little dish soap and water to help with the melting.

[Paul Phillips]

Phil, Onsrud make bits that are designed specifically for soft Acrylics that work well, try lower RPMs and a faster feed rate if you start to get melting.