Update on my feed rate test with aluminum brackets

I was making a batch of 50 aluminum brackets last month and decided to try something different. For the first 25, I ran my usual feed rate of 30 inches per minute with a standard 3-flute end mill. The finish was okay, but I got some chatter on the long edges. For the second half, I dropped the feed to 22 inches per minute and switched to a 2-flute cutter I had sitting around. The difference was huge! The surface finish was way smoother, almost no chatter, and the tool just sounded happier, less stressed. I think the slower feed let the 2-flute clear chips better in that soft material. It added maybe two minutes to the cycle time per part, but the quality jump was worth it for this job. Has anyone else found that a slower feed with fewer flutes works better for certain aluminum parts?

3 comments

3 Comments

jadew6310d ago

Read a forum post once where a guy swore by single-flute cutters for deep aluminum slots. He said the extra chip clearance from fewer flutes made a huge difference in finish. Your test with the 2-flute seems to line up with that idea.

oscar_ellis10d ago

Huh, I've actually had the opposite happen. Pushing the feed a bit faster with a sharp 3-flute gave me a cleaner finish on 6061. Slower just seemed to make it rub more.

gavinw453d ago

Yeah, chip clearance is the real key here. A slower feed can let chips get packed in and recut, which just tears up the finish. Sometimes you gotta push it to get the chips out clean.

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