Quote Originally Posted by Tenson View Post
I guess the key is getting enough chip-load not to cause rubbing.
When cutting plastics and aluminium that is exactly what you need to to. With other materials, such as wood, you tend to get away with too small a chipload as it just wears the cutter faster, instead of immediately breaking it.

Quote Originally Posted by Tenson View Post
I'm cutting 8mm sheet, so I did multiple 3mm pass' at first with a 6mm cutter and then did a finishing pass at full depth removing 0.5mm of material.
When I need a good finish on something made from aluminium I cut the part 0.1mm or 0.2mm oversize, then do a finishing pass at full depth, so long as it's not thicker than 25mm which is rare. You could try leaving less than 0.5mm as the lower force on the tool may make a difference, however the chipload may be too small unless the feedrate is increased...