PVC sheet machining

[FeldWill]

I got a small project that I'm trying to finish up on my home made CNC router. I started cutting into 1/16" Thk. PVC plastic sheet and first cuts came out great but then it started melting plastic sheet to the point that holes where cut out but got fused together. My feed is about 3 "/min, I'm cutting with the dremel tool at highest RPM.

Please see pics. attached for what the piece looks like and bit I'm using.

Any advice to what I need to ajust. I can not run coolant as it's just a hobby router sitting in the aptartment.

I also got a 1/16"THK. sheet of ABS plastic if that will work better, but I don't want to mess up that one. I got no room for error.

Thank You
WF

[Gundawg]

3"/Min is way too slow but you don't mention your RPM fastest setting does not tell me anything. Using 18000 RPM 1/16" bit 2 flute bit .002" chip load 72" per minute. This is just an example.

You must have a proper sized chip the chip takes the heat away from the bit if not you will get re-welding of the chips. I cut a fair amount of plastic and if you have it right the chips are warm and the bit can be handled and it is not hot after cutting and I cut dry no coolant.

Mike

[FeldWill]

May be my dremel is spinning the wrong way? (see pic. arrow indicates rotation of dremel)

W

[Gundawg]

I don't think it is a direction of rotation problem. I have no experience with routing using a Dremel tool but cutting anything you need proper speeds & feeds you also need the material held tight. Try speeding up your feed I doubt you can slow your RPM much without losing HP and stalling the Dremel. Good luck.

Mike