[iamwill]

Was curious, I have never milled HDPE before and wanted to run this by someone before I started...

I have a Probotix v90 with a Bosch Colt, I am cutting a 1/2" think piece of HDPE with a 1/8" 2 flute solid carbide bit.

So, the questions are:
Do I need to use higher RPMs than what I would use with wood or lower?
Should I travel faster or slower, or just keep it the same in travel speed?

I cut many different woods before, Birch Ply, Koa, Paduk, Maple, Pine, Wenge, and others, I have just never worked with HDPE before...

Thanks for the help in advance.

[ger21]

Do I need to use higher RPMs than what I would use with wood or lower?

Depends on what you used for wood, but generally lower.

Should I travel faster or slower, or just keep it the same in travel speed?

Again, depends on what you were using.

A single O flute is a much better choice for plastics than a 2 flute.

[iamwill]

I guess numbers would have helped....

I typically run the bosch colt around 28,000 rpms to 30,2000rpms for my wood cutting with a travel speed of 15-20 inches per minute.

For harder woods, I slow the cutter down to around 22,000 rpms. and my travel to 8 - 10 inches per minute.

Most of the stuff I have been cutting with has been with a 1/16" 2 flute (for birch ply) or a 1/4" or 1/8" 2 flute (for solid woods to include my hard woods)

With hard woods I have always gone lower and slower for RPMs and travel, but with HDPE, I see that it can melt easily if your not careful. Plus I would imagine it will gum up, fill the flutes and break the bit if it got too hot. That is why I am asking. I have the CAM file set to shave 1mm at a time in depth but it shouldn't sit too long in one place (except for the plunges).

Typically with wood, I take about 1/8 off at a time.

[ger21]

With a 1/4" bit, cutting hardwoods, you'd get far greater tool life at 15,000 rpm and 100ipm. For HDPE, I'd try about 20,000rpm and 125ipm.