Finally figured out why my chamfer mill kept chattering on aluminum after 3 months of fighting it

Turns out I was running it at 8,000 RPM with only 0.005 inch per tooth feed and after I bumped it to 12,000 RPM and 0.012 inch per tooth the finish went from garbage to glass in one pass so has anyone else had luck just ignoring the recommended speeds on the tooling chart?

2 comments

2 Comments

spencer_sanchez671mo ago

Isn't it funny how sometimes the recommended feeds and speeds feel like they're written for a completely different machine? I had a similar thing on a steel job where I was getting terrible tool wear at the book numbers, so I just cut the RPM in half and doubled the feed, and the tool life jumped up like crazy. It feels like those charts are more of a starting point than a rule, especially once you get into different machine conditions and tool holders.

xena_rivera631mo ago

Tossed the chart completely and went with my gut on a Ti job last month. I had a similar struggle with chatter on a 3 flute chamfer mill in 6061, and bumping the feed way up to 0.015 per tooth at 14k RPM fixed everything instantly. The recommended speeds had me babying it at like 0.003 per tooth which was just rubbing the hell out of the material instead of cutting. Sometimes you just gotta ignore the numbers and let the tool actually take a bite.