I have the Amana plastic cutting bits and I have the S&F dialed in pretty good on the 1/4 bit, but I am having a hell of a time getting the 1/8 bit dialed in. I am getting a good amount of burrs left on the poly, and I have the speed dialed in to be the least terrible it can be.
Here is the 1/4 settings:
Stepover - 30%
DOC - .02
Plunge/Feed - 80 IPM
RPM - 11000
I’m using the same settings for the 1/8. If I go faster or slower on the feed the burrs look worse. If I reduce the DOC, it looks worse.
Here are a few video captures of me using that same 51411-K in acrylic, at 16.000RPM & 54ipm, which translates to 10.000RPM and ~33ipm, and getting half-decent cuts but with some level of chip packing in the slots
14ipm@10000RPM on that single flute is a 0.0014" chipload, which is ok (one can usually pull off several times that in acrylic, but at least it’s not rubbing…)
Are you using dust collection ?
EDIT: Amana says 70 to 110ipm at 18000RPM, so 38 to 60ipm at 10000RPM would be the sweet spot for them
For comparison, Amana is recommending a chipload of 0.0039" to 0.0061 at a 1/8" DOC. You are at 0.0014" chipload at only 0.04" DOC. I would be very comfortable cutting at 70 IPM and 18000 RPM at 0.06 DOC and I bet you could go deeper. This is something like 300% faster material removal than what you are doing. I bet you are getting the burr because the plastic is melting a bit. Going fast is almost always the key with plastics.