I want to try to make some signs with v-bits (3mm and 6mm bits) and need to know which speed of rotation and feedrate I need to use in order to prevent melting. The material is 6mm Styrene-Acrylnitrile (SAN). It is covered with a thin protection film. Do I need to remove that before machining?
I´ve also seen that other recomend a mix of water and dish detergent as cooling fluid. Can I use that without risking rust on machine parts?