Sorry if the text is badly written but I speak French. I’m new at machining. I’m trying to make eyeglasses frames with cellulose acetate. However, I have a major problem. I can’t get a precise cut. As soon as the bit sinks a millimetre into the material, the plastic heats up and becomes completely soft. It is then very difficult for the bit to finish the job and the result is very bad. I changed the speed, the size of the bit, the rotation speed of the bit, etc. There is nothing to do. I use 3.1 mm O flute bit. Do you have any suggestions? Do you know the right cutting speed, rpm, etc.? Thank you in advance.
What spindle speed, tool type (coated? bare carbide?), feed rate, and cutting strategy? What software?
As a general guide, coated tools tend to do better with many plastics (less tendency to stick, less friction as the chips move out), and you usually want an appropriate feed rate to prevent the margin and clearance of the tool (the region adjacent to the cutting edge) from rubbing and get thick enough chips that they will clear without packing or sticking in the flute. This is often more aggressive that you might think.
What @enl_public said (basically, you are probably not feeding fast enough).
Also:
si tu veux de l’aide en français, envoie moi un message privé et j’essaierai de te conseiller.