That time I chased a 0.005 inch offset for 6 hours

I had this part on a Haas VF-2 in Cleveland where the bore was coming out 0.005 off center. Spent a whole shift checking work offsets, tramming the head, even swapped tool holders. Turned out the vise was just slightly twisted from a chip caught under the jaw. Took me 6 hours to find something that should have been a 10 minute fix. Anyone else ever spend half a day on something that simple?

2 comments

2 Comments

seth_martinez2118d agoMost Upvoted

Did you check for chips under the vise before you started re-tramming everything? That's the first thing I do now after getting burned the same way. I had a similar problem years ago. Spent 4 hours chasing a bore that was off 0.003. Pulled the whole vise off and found a tiny piece of aluminum shaving wedged under the key. Felt like an idiot. Now I always blow out the vise base and the T-slot before I even clock a part. Saves me a lot of headache. So what was your process for finding it in the end?

juliagonzalez18d ago

Our shop had a guy years ago who spent an entire Friday chasing a tool length offset that was off by about 0.002. He changed tools, re-zeroed the probe, even ran a full machine alignment routine. Around 4:30 he found out the new guy had set the wrong tool number in the program for a finish end mill. Three minutes to fix once he saw it. We all had a good laugh at the bar that night. Makes you wonder what else we overlook when we get too focused on the big picture stuff.