Just caught a sneaky spindle load mismatch that could have trashed a $1,500 endmill

I was running some 304 stainless parts yesterday on a Haas VM-3 at the shop near Portland. My programmer buddy always says to trust the machine's load meter, but something seemed off because the spindle load was reading 110% on a finish pass that should have been about 40%. I stopped the program and checked the actual cut using a cheap laser tachometer I keep in my toolbox. Turns out the spindle speed was actually 4,200 RPM instead of the commanded 8,000 RPM. The parameter 406 for the spindle encoder was corrupted somehow, probably from a recent power surge. If I had let it run like that for another 30 seconds, I would have rubbed that carbide off clean. Has anyone else dealt with parameter corruption on older Haas controls? I am thinking of adding a routine to verify spindle speed at the start of every batch now.

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1 Comment

young.emma15d ago

I read about a guy on Practical Machinist who had the same thing happen on a 2008 Haas. He said parameter 406 gets corrupted from dirty power in the shop. I keep a cheap IR tach in the drawer now too. Checking spindle speed on every first part of a run is just good insurance.

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