Quote Originally Posted by magicniner View Post
Carbide endmill on plastic screams problems unless you have a particularly sharp edge, try a high speed steel cutter with a very sharp edge.
Ahh so that's why it was pushing the plastic instead of cutting. Very thin cut too so that wouldn't help.
I don't have any hss bits yet but I'll put a wooden board in top of the plastic and surface that with the carbide bit and see the results. Just trying to check everything is square and true.

Thanks very much