@Luca_Nervetti milling some acrylic with ChiliPeppr. I do a lot of acrylic too and it’s hard to not get it to melt at the end mill. Looks like he nailed it.
https://www.youtube.com/watch?v=p7LF9KBlamA
Hmm. Sadly I don’t know if it’s cast or extruded. Maybe one melts less than the other?
Chemically they are two different materials… And one has an extrusion grain while the other has a crystalline structure… Not sure if it makes much difference with the CNC only used extruded… But with the laser you get a frosty engrave with cast and a glossy/glassy engrave with extruded
I have both on hand and will need to run CP on some wood, will give a try next time that machine is fired up
Did you try using alcohol mist or plain air for cooling?
I have an odd way I deal with this on my mill but it may be helpful John. It takes test cuts and scrap material but works.
I have a RPM reader device and a manually controllable spindle. I do test cuts in one direction at set speed and manually adjust the RPM until I hit a speed that cuts without difficulty but doesn’t burn. I then read the RPM with the doobery and set the output PWM for approximately that.
I use air to cool it, but maybe something more aggressive like mist could help. I was taking 1 mm deep depth of cuts in slots and had to dial that back to 0.5mm. I can take 4mm depth of cut if i’m doing an adaptive clearing. I’m learning the nuances of this material.
Hi to all 
this kind of material is very easy to cut. I have also other different pieces of I think is plexiglass and some time it’s melt on the bit. I found that if I use a 3mm double flute end mill I can cut that with no melting. I will do a video comparison of bits and material.