Milling .0625 ABS - Lessons Learned

So I just went through a series of interesting exercises in trying to do some precision milling of 1/16 ABS. First the problem: ABS has a really low melting point so you have to have a one or two flute upcut bit to make sure you properly evacuate the chips so they don’t melt back. The big issues for 1/16 ABS is that is is very thin and pliable so trying to hold it flat to the table for things like lap seams is virtually impossible. Between the dust mitigation system and the upcut bit the material lifts even on a vacuum table.

Tried : I tried a number of solutions like lowering my spindle speed way down and increasing my feed rate and even going without the dust mitigation but to no luck.

Solution: So in the end I had to switch to a DOWNCUT bit to force the material down. To avoid the chips accumulating I cut very very shallow (.005) and very fast 75IPM. The cut is shallow enough that the dust mitigation system did and adequate job of evacuating the chips while moving fast enough to keep the bit cool.

I am just posting these as application notes in case anyone else wants to work with this amazing material! The end result was a smooth and very accurate cut.


Great information, thanks for sharing!

What spindle speed? What endmill?
I don’t have an X-carve, but I’d guess my machine is somewhere in between the X-Carve and the Pro. I would probably start closer to double your feed for a soft plastic like abs.
That depth is sooo shallow too.

I’d also use tape and CA glue for workholding.


I have an XCP and I settled on 16500 for the spindle speed. Tried a number of upcut endmills including and O flute and fishtail. I settled on a downcut fishtail endmill. I suspect I could go even faster.
Thanks for the feedback!

Also tried tape and CA method. and that helped, but this is two color material and I cut from both sides depending on the part and they are color specific.

was a straight cut endmill in the mix? these create larger chips than an up or down (not as large as an o-flute though) but also don’t have the pulling up issues that an upcut would have…

Unfortunately that was one of the things I wanted to try (a compression bit also) but I did not have either in 1/16th bit. I will get some next bit order and try.

I did try increasing my feed rate to 150 and got even better results.


That’s better!

Personally, I would not use a downcut or compression bit with anything related to plastic…


Brandon Parker

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