Realized I was overthinking my feeds and speeds on a job last week

I was running a 3/8 end mill in aluminum and kept getting chatter no matter what I tried, even dropped my speed down to 1800 rpm. Finally remembered a tip from an old machinist about increasing chip load instead of babying it, so I bumped the feed rate up to 12 IPM and it cut like butter. Anyone else find themselves fighting chatter by going slower when you should actually go faster?

2 comments

2 Comments

sarahsullivan10h ago

1800 rpm sounds low for aluminum tbh

lisa_jones2110h ago

Going slower and lighter keeps tool deflection down and prevents work hardening in aluminum, so sometimes the old school light passes save more headaches than cranking up the feed.