A guy at a trade show in Cleveland made me rethink how I set up my work offsets

I was at the IMTS show last year, just walking the floor, and I stopped to watch a demo on a new Okuma lathe. The operator running it, an older guy with a shop shirt from Ohio, was showing how he sets his G54. Instead of just touching off the part, he explained he always takes a light cut first, measures that spot with a bore gauge, and then sets the offset based on that actual cut dimension. He said, 'Your tool might be off a thou from wear or the insert isn't seated perfect. The machine thinks it's at X, but the cut tells you where it really is.' I'd always just trusted the tool setter and the touch probe. Tried his method back at my shop on a tricky stainless job, and my size consistency got way better. Has anyone else moved to a 'cut, then set' method for critical work?

3 comments

3 Comments

jana_jones6d ago

Oh man, that hits home. I was SO confident in my probe until I scrapped a whole run of aluminum hubs. The tool was just barely pulling out of the holder, like half a thou. Now I do a "prove it" cut on the first part every time, especially after a tool change. It adds two minutes but saves a giant headache.

karen3616d ago

Half a thou is all it takes to turn a hub into a very expensive paperweight. Your "prove it" cut is basically the machine shop version of poking a bear with a stick to make sure it's really asleep. Two minutes of paranoia beats eight hours of explaining to the boss why the scrap bin is full.

allen.kai5d ago

Wait, half a thou? That's like... a tiny bit of dust. You're telling me that scrapes a whole part? I guess I've just never worked with stuff that tight. Seems like a lot of fuss for something you can barely even measure.