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I finally figured out why my tool offsets kept drifting on the VF-2
Ran a job last week on a Haas VF-2, some aluminum brackets, nothing crazy. But every 20 parts or so I'd check the first piece and find the Z was off by like 0.003. Drove me nuts. I cleaned the tool holders, checked the drawbar force, all that stuff. Then I noticed it was always after I used the 3/8 end mill, never the other tools. Turns out the collet nut on that holder was cracked. Not bad enough to see without really looking, but it was letting the tool slip under heavy cuts. Found a tiny hairline fracture along the thread. Swapped to a new holder and ran 100 parts without touching the offset. Has anyone else had a collet nut that looked fine but was actually wrecked?
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butler.brian26d ago
Man have you checked the torque on your collet nuts lately? I had the same thing happen with a face mill holder on a Mini Mill 2 and it was the dumbest thing, the nut was torqued to like 30 ft-lbs instead of the 50 it needed and it let the tool creep just enough over a few cycles to throw everything off. You might want to pull that cracked nut off and compare it to a fresh one side by side, sometimes the threads get galled up in a way you can only see with them next to each other. I keep a spare set of collet nuts now just for that reason after I lost a whole batch of parts to the exact same problem.
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nora53525d ago
Yeah that's not how torque works on a collet nut though. You're supposed to bottom it out by feel, not hit a specific ft-lb number, overtorquing is actually what cracks them.
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