I have built a cnc "lathe" to engrave cylinders, and I am seeking advice on the type of bits to use to engrave lithophanes on PVC pipe. I have tried 30° V bits, but results are dismal due to the PVC melting. I am presently using a Dremel, but will install a trim router (Bosch or Ridgid) soon.

I use my own gcode conversion program and usually engrave with a step over of 0.005 to 0.010 inches.

Thanks for any advice.

John