We live in a world of injection moulded plastic, curved surfaces are commonplace and it is easy to start thinking they are easy.

CNC mills do curved surfaces as facets or use custom cutters which will cut one set curve.

There are 2 approaches for this, cut it in 2.5D with a ballnose, cut it in 3D with a flatnose.

The ballnose cuts a round bottom groove so the facets have to be smaller and there is a lot more cutting to do.

The flatnose requires one hell of a machine, an uncommon beastie.

Polycarbonate? Are you hoping these will cut shiny and see through? :heehee: