Max MRR in plastic?

[WillAdams (William Adams (Carbide 3D))]

We do have Delrin and HDPE for 1/4" tooling listed at:

and I used them successfully on some cutting boards from the local restaurant store.

We do have some notes linked to from: https://wiki.shapeoko.com/index.php/Materials#Usage_notes_.28Carbide_3D_HDPE.29

Rowmark Heavy Weights - HDPE panels

I mill almost exclusively HDPE. Usually I’m around 1 or 2 on the DWP611 speed and I feed about 750mm/min with a two-flute carbide end mill. I find I can do about a 4mm maximum depth cut before I start having rigidity issues, but for roughing a full plunge slot at this speed I get significant chatter in the Y direction, where my SO3 is least rigid. I also opted for the standard size SO3 due to rigidity concerns. To improve your cut, I would recommend the following: Play with feeds and speeds w…

Tutorial on feeds and speeds

I got a successful cuts done today in HDPE. Parts for my dust boot. The 34 mm/sec with a 1/4" flat cutter at 3.17 mm step was way too fast. Router speed makita at 3. Had a perfect cut at 12 mm/sec, 3.17 step and router at 4 makita with 1/4 " flat carbide3d cutter. 1/2" hdpe in 4 passes. The side shields and pulley covers worked fine also. Put the boot together tomorrow and no more mess, I hope. Oh yeah, the cutter stayed cool to touch for every cut, not touching it running but when changing too…

There are some recommendations for endmills for plastics at: https://wiki.shapeoko.com/index.php/Endmills#Plastics