Old timer told me to stop chasing tenths on my setup

I used to spend like 15 minutes dialing in every tool to within half a thou. One of the senior guys at the shop in Portland watched me one day and said 'hey, youre wasting time chasing air. If the part calls for +- .005, just get it in the window and run.' So I started backing off to about .002 and my cycle times dropped a ton plus I dont feel burned out after the first hour. Anyone else have a moment where someone made you realize you were overthinking it?

3 comments

3 Comments

piper7791mo ago

Were you chasing tenths because you thought that's what made you a "good machinist", or was it a control thing? I've had that same conversation with myself a few times, and for me it was mostly about wanting to prove something to the older guys. But once I backed off, the parts still passed inspection and I actually had energy left to think about setup tricks instead of just grinding. Did your parts actually start failing when you loosened up, or did you just have to trust the process for a bit?

kimmurphy1mo ago

Wait, you're saying you backed off and the parts STILL passed? That's honestly blowing my mind a little because I spent YEARS convinced that if I wasn't scraping down to the last tenth I was somehow cheating the machine. @piper779 it sounds like you had the exact same pressure from the old school guys that I did, but your story is making me wonder how many hours I wasted on nonsense. I never actually tried trusting the process, so now I'm sitting here wondering if my parts would have been fine all along.

finley_gonzalez491mo ago

yeah I read this whole thing about how on older machines the thermal growth alone would eat up those last few tenths anyway so chasing them was literally a waste of time and coolant. like the part would move from the heat of cutting before you even finished measuring it kinda stuff. once I saw that explained somewhere it kinda clicked for me why the old timers were so paranoid about everything being ice cold before they'd even look at a mic. but honestly I think the real lesson is that print tolerances have a reason for being what they are and if you're way inside that you're just burning time for no benefit.

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