Most of the work I do is of a temporary nature, so the edge quality doesn't become an issue. I recently had another job to make some Corbels out of AZEK and I was less than happy with the edge quality.
The corbels were each made in four pieces like a sandwich, with scrolls on the outer two surfaces.
I cut some of the job with a 1/4" down cut and some with an up cut spiral.
Cuts were done in 4 passes on 3/4 inch material and 5 passes on 1 inch material. I don't remember the exact cutting speed but I got shavings - not dust. I'm thinking it was probably around 2 inches per second at 13,000 rpm. Porter Cable router.
I can check the log files when I get back to that computer.
Hold down was screws in the corners of the sheets and I had two or three tabs holding each part in place. More tabs would have been better but I had 92 pieces to cut from 8 1/2 sheets so...
I replaced the pinions on my 2001 PRT96 last year and 99% of the time I cut EPS foam, so there is little stress on it to wear things out.
But the interesting thing about the steps I get on curves is they are in the same place on the same parts.
So I thought I would post photos of the edge of the parts to see what others think is the cause. Mechanical, part file, hold down, cutting strategy, bit selection, all of the above?