Help with cutting acrylic

I am trying to cut out Christmas ornaments from cast acrylic and they seem to be melting and breaking apart. What type of big should I be using ? Or should I try a different material to cut them from?


The cast acrylic is perfect.
You should be using a 1 flute bit and a high rate of feed (I use 100 IPM)
The chips coming off of the cutter should look like pieces of rice.
Hope this helps.

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I don’t have a 1-flute bit, so I use a 2-flute straight cut bit. Bottom line though as Jan said, go faster if it’s melting because it’s generating too much heat.

Thanks for the help I will give it a try this evening and see how it works out!!

I cut a fair amount of acrylic, here’s my formula:
2-flute spiral up-cut bits - gets the chips out.
Shallow cuts (many passes) at higher speeds. My passes are usually 0.008" deep…but that can change with bit diameter too. Although I dont cut at 100 ipm, I am typically 70 ipm to 80 ipm.
Chip removal - blow them away or suck them up…one or the other, just get rid of the chips/dust.

A couple other things… I added some 1/2" square tube to the side rails to reduce flex in the X axis…got rid of a lot of chatter that my machine made when cutting acrylic. Not saying its a fix all, but it worked for my situation. I also always use the tape and CA glue method for holding material when cutting acrylic. Again, my situation…when using an upcut bit, if the material is only held down on the edges, there was a tendency for the bit to pull the center of the material up off the spoil board. The tape and CA glue method secures the whole surface of the material.

Lots of experimenting…hope some of this helps.