Engraving HDPE

[Nick1983]

I was wondering if anyone had any tips on engraving HDPE with a CNC router. I am able to get it to cut ok but I am sure there are better ways. The main problem is getting the scrap material out, it is sticking.

Nick

[SCRAPWOTSCRAP]

What spindle RPM are you running???? You might try lower rpms to get right chip consistency.

[Nick1983]

22,000. Cutting with a 1/16" dia double flute straight cut bit.

[SCRAPWOTSCRAP]

I'm betting you get quite a bit of melt at 22k, try 14k, I have pretty good luck at that rpm, chips are like a fine powder and no melt.

[Nick1983]

A little bit of melt is an understatement. I was cutting all the way through the hdpe today and it caught the mdf table on the router on fire. It was crazy. So a lower rpm will fix that, good to know thanks. What feedrate/bit do you have the best success with?

[SCRAPWOTSCRAP]

Pretty much every machine and spindle are different in my experience. Higher rpm's on router spindles are for wood, not necessarily for plastic. As a rule of thumb if the melt is a problem, slow down the rpm's and increase the feedrate if possible, blowing compressed air on the bit can help too. If you have problems, play with speeds and feeds and learn as you go. That's why they put them knobs on the control panels!!! lol

Laterrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr

[Nick1983]

I am still fairly inexperienced CNC milling plastics. My backround is more in metal so it is fun. Appriciate your advise.

Take care
Nikc