Bits for plastic?

Hi…I’m new here and l need help… l try to carve and cut plastic (HD-PE&PP) with all recommend bits but without luck? I need clean bottom surface!Where is the trick?!

The most important factors are:

  • Machine fully rigid on all axes, no flex.
  • Spindle 100% in tram
  • Large diameter bit, single flute
  • High quality end mill, fresh and sharp.
  • Low RPM and appropriately fast feed rate

You shed no light on your bit/rpm/feed rate data, please elaborate on that.

Agreed. The low RPMs are the key.

My suggestion would be to create a multi-toolpath with a handful of different shapes. Set each to a different feedrate/RPM and test on your material. Hopefully that will get you your appropriate feed/speed in one swoop. HOPEFULLY.

With plastics, you want the material to chip away, not melt. That’s the difference between high and low RPMs

Also, I know they make “flat bottom” bits for smooth pocketing. I can’t remember the technical “googleable” name. Anyone?