I tried bumping my spindle speed up 20 percent on 6061 and the finish got worse, not better
Everyone kept saying to push aluminum harder so I ran my 3 flute at 9,000 rpm instead of my usual 7,500 on a batch of brackets for a guy in Tucson. The chips came out like dust instead of proper curls and the side walls looked like sandpaper, plus one end mill chipped a corner. Turns out my little router style spindle just doesn't have the torque up there and I was rubbing more than cutting. Anyone got a rule of thumb for finding that wall without trashing tooling?