Figured out my tool offsets were off by 0.003 after three months of rejects

I was fighting with surface finish on a batch of aluminum brackets for weeks, and then I finally checked my tool height offsets with a test indicator. Turns out my Z axis was drifting 0.003 inches over time because I wasn't tightening the drawbar enough. Has anyone else had a similar issue with their machine losing accuracy from something simple like that?

3 comments

3 Comments

drew_reed621d agoMost Upvoted

Oh man, I once chased a 0.002 error for two months before realizing I had a chip stuck under a clamp.

rubyshah21h ago

Did the bracket have any weird flex in the workholding too @drew_reed62? I've seen stuff like that where the surface finish goes south because the part moves just a hair when the tool hits it. Makes you want to quadruple check everything before you run another part.

craig.john20h ago

I see @rubyshah mentioning part flex but honestly 0.003 over three months doesn't sound worth throwing away that many parts over. You had to have noticed some other signs way before that. Seems like a good excuse to blame the machine instead of checking your setup sooner.