I cut some 0.030" acetal with a 50W epilog last week and didn't have any trouble.
I can probably look up the %speed and %power if you need it but I do remember the frequency was around 600.
I also tried to cut some 0.5" acetal a couple weeks ago and i was able to get through it in about 4 passes (although I decided to mill the rest of the parts) at 3%speed 85% power and 600 freq.
GO-Tech: Geek Show&Tell Meets Ann Arbor 2nd Tues at www.maker-works.com
South East MI cnc meets 1st Wed at www.maker-works.com