My maxnc10 at work. Now cutting a piece of acrylic to become a bracket for the z limit/home switch on this same machine.
What feed and rpm are you using? I’ve had trouble with acrylic melting before.
I was using a setting of 2000 RPM, whatever that is at the tool.
The motor speed has not been calibrated, but lets say its about 1/4 of full speed (8000). Then the pulley is reducing this with a factor 2.5 or so. The tool RPM must be therefore be just about 800.
Its my very first cut ever with a CNC, but I have some experience with cutting acrylic, so I was aiming at a low speed initially, and it worked - mostly 
I cut another bracket for the y axis limit switch and did this with approximately 400 RPM at the tool and a feed speed of 90 mm/min using a 3mm tool. That worked quite well and made nice chips. It’s slow but nice. Perfect for this little machine.
I made the mistake to mount the work piece to be extending over the edges of the supporting piece. That resultet in early breaking off when the milling was almost complete. The cut item could still be cleaned up and used, but I’ll not do that mistake again.