Old timer told me my feeds and speeds were way off for aluminum, had to eat crow

I been running a Haas VF-2 for about 4 years now and thought I had aluminum dialed in. Then this retired machinist named Frank walks over during my shift at the shop in Grand Rapids last Friday, watches me cut a 6061 plate, and just shakes his head. He said I was running the spindle at 8,000 RPM with a .002 inch per tooth feed on a 1/2 inch end mill. He told me I was basically rubbing the material, not cutting it, and that I could double my feed and drop the RPM to 6,000 and get way better chip evacuation. I thought he was full of it but he showed me on his phone a chip thinning calculator. So I tried it on the next part and the finish was way smoother and the tool didn't squeal anymore. Has anyone else had to relearn something basic after years of doing it wrong?

2 comments

2 Comments

reed.eva1mo ago

Love that gut check feeling.

paul_webb451mo ago

You ever have a buddy who swears he's been setting up his lathe right for a decade? My friend Mike had a similar thing happen with stainless steel. He ran a shop in Detroit and some old school tool rep came in and told him his insert was chipping because he was feeding too slow. Mike tried cranking the feed up like 30 percent and the chatter disappeared and the tool life tripled. It's funny how you just get stuck in your old ways and don't realize you're leaving performance on the table.