HI Don.
I cut acrylic a lot. It was suggested on this forum that air cooling is good, and now I have it set up I agree, but it ain't a $300 dollar vortex it's a pipe from a compressor. A very thin jet straight at the bit. It is so effective that when I turn the air down there is a point where all the cuts are clean excecpt those odd ones in the direction that is sheltered by the bit, and in that region there is a touch a hint of rewelding.
Just thought it might help
Jim