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Blew through 30 end mills before figuring out my speeds were trash | CNC Operators - HW Forums

Blew through 30 end mills before figuring out my speeds were trash

I was running a job on a Haas VF-2 last month cutting 6061 aluminum and kept snapping end mills left and right. My foreman came over and watched me for like 10 minutes before he said 'dude, your chip load is way too high for that tool diameter'. I had been running at like 80 IPM with a 1/4 inch end mill at 10k RPM, thought it was fine because the machine sounded aggressive. He showed me the calculator on his phone and I felt like such an idiot, been machining for 2 years and never bothered to check feed and speed charts. After I slowed it down to 50 IPM and bumped the RPM to 14k the tools started lasting like 3x longer. Has anyone else had a basic setup mistake that took way too long to catch?

2 comments

2 Comments

seth_green851mo ago

Wait, hold up. 30 end mills? In one job? Dude, that's like burning a month's tool budget in a day. I've been machining about 6 years and I've never snapped more than 3 on a single run, I can't even imagine that bill. Your foreman must have been real patient, I would have just started laughing after the first 10.

the_anthony1mo ago

Nah bro you're overthinking this. 30 end mills is nothing if you're pushing feeds and speeds hard on some nasty material like inconel or hardened tool steel. I've seen guys go through a dozen before lunch on a roughing pass. Your foreman laughing after 10 is cool but he's probably not the one running production parts where scrap costs more than the tooling. Sometimes you gotta burn through cutters to hit cycle time and get the job done. Plus if they're cheap Chinese carbide you can buy a box of 30 for what you'd pay for 5 good ones from Kennametal. Tools are consumables, man. They're meant to be used and replaced.