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That old-timer at the shop in Tulsa gave me bad feed and speed advice
A retired machinist told me to run my HSS endmill at 3000 RPM with a .005 chip load on 6061 aluminum. I tried it on a part last Tuesday and the tool snapped after 10 inches of cut. Then I checked the manufacturer's chart and saw I should have been at 1800 RPM. Has anyone else gotten bad advice from guys who used to run manual machines?
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henrygrant13d agoTop Commenter
You ever get that feeling where someone's advice sounds like it came from a different planet? I had a similar thing happen with an old timer at a swap meet in Wichita. He swore by running a carbide endmill at 6000 RPM in stainless steel with a heavy chip load. Said he'd been doing it since the '80s. I tried it on a small job and the tool started glowing red after like 30 seconds. Had to stop and let it cool down. Turned out the manufacturer said max 4000 RPM for that cutter. I think those guys forget that modern tooling and machines are built different from the old Bridgeports they ran.
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piper_dixon4513d ago
I remember reading somewhere that old school guys often ran stuff way beyond modern safe limits because their machines were so underpowered they'd stall before things got dangerous... @henrygrant that glowing metal story is wild though, sounds like you found the edge real quick.
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