Had a part run out of tolerance by .001 and the boss blamed my setup

Last week I was running a batch of 50 aluminum brackets on our Haas VF2, everything looked good on the first piece. By part 15, the boss came over with a mic and said the bore was off by a thousandth. He said I must have messed up the tool offset when I set it up Tuesday morning. I checked my notes and the tool was right where I put it, cold machine maybe? Anyone else get weird size shifts halfway through a run like that?

3 comments

3 Comments

the_alice23d ago

Wait, cold machine causing a .001 shift halfway through a run? That doesn't sound right. If it was cold, the first part would be off, not part 15. Could be something warmed up and moved, like the spindle. Had a similar thing where the drawbar force was low and the tool pulled out just a tiny bit after a few parts. Your boss jumping to setup is annoying though.

ward.anna23d ago

Ugh, does your boss not get how much machines move around? Same thing happened to me last month on our older VF3! First ten parts were perfect, then a slot started creeping wide. My lead blamed my tool wear offset, but it was a brand new endmill. Turned out the coolant hose was hitting the part and nudging the vise, just a tiny bit. Took me forever to find it.

abby_morgan1822d ago

Tell me about it, bosses always go for the easy answer. Mine would have made me redo the whole setup before even looking for a real problem. Glad you found that hose, those tiny bumps are the worst to track down.