Old timer told me my speeds were way off. He was right.

Been running a Haas VF-2 for about 3 years now. Thought I had feeds and speeds dialed pretty good. Then an old timer walked by my machine last month. Watched me cut some 6061 aluminum. He just said, 'You're killing your tool life running it that slow.' I was running at like 8,000 RPM with a 1/2 inch end mill. He told me to bump it up to 12,000 and increase the feed rate by 30 percent. Felt risky. But I tried it on a test piece. Cut time dropped by 40 percent. Tools are lasting way longer now too. Has anyone else had someone just call out their settings like that?

3 comments

3 Comments

alice_palmer2019d ago

Gotta push back a bit on miamitchell here. I ran 6061 at 1200 SFM for a while after hearing the same advice and it chewed up my tools faster, not slower. My setup's solid too, a Brother S700 with good holders. The problem I kept seeing was the heat buildup at those speeds even with good coolant. Dropped back to 850 SFM and bumped my feed way up to compensate, and my surface finish actually got better. Chip thinning is real but you gotta watch your radial engagement or you'll get that little built-up edge that ruins your part.

miamitchell1mo ago

Experienced machinists know, 6061 likes 1200+ SFM with proper chip thinning.

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the_tessa1mo ago

Running 6061 at 1200 SFM sounds like a good way to burn up an end mill if you're not careful. Most guys I know keep it around 800-900 and still get clean cuts without pushing the limits. Chip thinning is real, but jumping that high feels like a fast track to chatter and a bad finish unless you've got a really rigid setup.