Finally got the chatter out of that deep pocket on the aluminum housing job

I was running a 3/8" end mill at 8 inches deep on our old Haas, and the noise was just awful (like a bag of wrenches, you know?). After three days of messing with speeds, feeds, and even the coolant mix, I dropped the RPM by 200 and took a lighter final pass, and it came out smooth as glass. What's your go-to fix for chatter on a long reach cut?

2 comments

2 Comments

palmer.henry11d ago

Honestly, you just slow it down? I'd have gone the other way and cranked the RPM up first. Doesn't a faster spindle usually help with that?

david82111d ago

Slowing the spindle down was the right call. I've seen guys like palmer.henry try to speed through it, but that just makes the tool whip worse on a long stick-out. On a 1/2 inch end mill going 6 inches deep in steel, I'll drop the feed by 30% first, then maybe the RPMs if it's still singing. A lighter finish pass is almost always the final step for me, just like you did. Sometimes you just have to let the tool cut easy instead of fighting it.