Doing some programming for someone that has a router and they are cutting .220" thick acrylic. Machine has a 3hp 21,000 rpm Porter Cable spindle and we are cutting a shallow pocket (.090" Deep) and cutting through the sheet on the perimeter of the part. I do mostly CNC mill work and have no experience with 21,000 rpm and cutting acrylic.

I have machined it (acrylic) on my CNC mill but that spindle is only good for 3000-4000 rpm, other than that I cut it with my laser. So what's a good starting point and possible upper limit for feed rates? I'm using a 1/4" 2fl carbide end mill at the moment and have suggested they use and Onsrud 0-flute with an 11º spiral instead... running 100ipm now and it seems likes the machine could handle quite a bit more.

Oh, it's a 4x4 router made by Phoenix, don't know much about it, but it seems pretty solid, not some little table top aluminum extrusion contraption.

Thanks in advance!