jason_lewis3•1mo agoProlific Poster

Am I the only one who saw a 30% drop in chatter marks after switching to a 3-flute endmill for aluminum?

I mean, we were getting a lot of rework on these 6061 parts until the shop lead suggested the change about two weeks ago, so has anyone else found a better tool for finish passes?

4 comments

4 Comments

mary_west1mo ago

Avery's point about feed rate is huge. We learned that the hard way on some thin wall parts. The three flute just sat there and squealed until we pushed it harder. It felt wrong to go faster, but the finish cleaned right up. Now we treat it like it's hungrier and give it more to chew on each pass.

avery_ross1mo ago

Switching to a 3-flute was a game changer for us too, but the real trick was bumping up the feed rate. The extra flute needs more chip load to work right, otherwise it just rubs and heats up. We were running it too slow at first and still got marks. Cranked it up 20% and the finish got way better. Might be worth a look at your speeds and feeds if the marks are still there.

tessa_murray1mo ago

My uncle runs a small cabinet shop and he had the exact same problem with his planer. Kept getting those little lines on oak, drove him nuts. He was convinced it was a dull blade but it turned out his feed roller pressure was way off. Took him a week of fiddling with it to find the sweet spot.

miller.rowan5d ago

Hold on a minute. I've been running 2-flute endmills in aluminum for twenty years and I'm not convinced this is a universal fix. The 3-flute tools can create more harmonic vibration in certain setups, especially if your machine isn't rigid enough, and that vibration shows up as those same chatter marks. @mary_west mentioned feed rate, which is important, but swapping to a 2-flute with a high helix and a light radial engagement gave us a better finish on our older mills than the 3-flute ever did. Seems like it depends a lot on your specific machine and how well it's trammed in.