Vent: That toolpath that ate my part and cost me a shift

Last Tuesday I was running a job on our Haas VF-2 at Precision Parts in Cleveland. I had this aluminum bracket programmed with a 3/8 end mill, everything looked fine on the sim. But I forgot to tighten down the collet nut all the way after a tool change. About 30 seconds into the rough pass I heard this horrible screech and the tool walked right out of the holder. It dug a spiral groove through the part and snapped the end mill in half. The whole piece was toast, scrap value only. Took me 2 hours to reset the fixture, re-clamp a new blank, and re-run the program. Has anyone else had a similar brain fart with collet or holder issues? What do you double check before you hit cycle start?

2 comments

2 Comments

the_john15d ago

You had the collet nut that loose and still hit cycle start?

wesley_fox9214d ago

Hang on, are you saying it's my fault the machine ran that collet nut loose? I get what you're saying about checking things before you hit go, but sometimes you inspect it, it feels tight enough, and it still walks on you. I've had jobs where I torqued the nut to spec and it still shifted after the first pass, especially with a heavy cut in stainless. A loose collet isn't always from not tightening it, sometimes the part itself pulls it out of whack under load. I'm just saying, there's a difference between being careless and the cut fighting back.