Colorcore v bit issue

[Ken853 (Kenneth Hartling)]

Appreciate the information and advice.
-Ken

[MadHatter]

I have used these bits on UHMW, HDPE (Starboard) and cast acrylic, but not color core, and they worked well - definitely did not leave edges like you are experiencing.

And I second what @wmoy wrote - the woodworking bits have the wrong bit geometry for soft plastics. I believe it is the rake angle that is causing you the issue, but not 100% positive.

[Emmess (Matthias Solga)]

Did some plastic (acrylic, colorcore), key is to

1. reduce heat
2. get the heat away from the plastic as soon as possible
   (not my research, read it somewhere, but is true).

How to achieve?

1. cut with the slowest possible RPM. I use 4k, the lowest the spindle can give. And use as little contact area as possible, so one flute with sharp tip, and that is an “O”-flute. V-bit does certainly not fulfill that requirement.
2. fastest cutting speed possible, I have to look it up, did not cut plastic for a while, but 150ipm appear much too slow to me.