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Debate: do you climb your parts on the machine or check them offline?
I had to make a call on a job running 316 stainless brackets last month. My usual move is to check the first part right on the machine with a height gage and mic, saves time. But the foreman said I should pull it and walk it over to the CMM in the QC room for a full inspection before running more. The first part took 20 minutes for a full CMM report and my cycle was only 8 minutes per part. What side do you land on - quick checks on the machine or the full offline inspection?
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julia_anderson5d ago
Why would you waste that kind of time on a first piece? That foreman cost you money and killed your momentum. You can check critical dimensions on the machine in under 5 minutes with a good mike and height gage. If you know your machine and your tooling, you can tell right away if something is off. Taking a part to the CMM for a full report on the first one is overkill unless you're running aerospace or medical stuff. On a simple stainless bracket, you're better off trusting your eyes and your hands. The CMM is for final verification, not for babysitting the setup.
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stellanelson5d ago
You mentioned trusting your eyes and your hands, and I get that, but I think that's exactly where people get into trouble with a first piece. In my experience, the first part off a setup is where all the hidden problems show up, and a quick check with a mike won't catch a warped edge or a slight shift in the fixture that'll throw the whole batch off. If the foreman is worth his pay, he should know that killing momentum now beats scrapping a hundred parts later because you trusted your "feel" on a bracket that ended up out of square. I've seen too many good machinists rush through a first piece and end up remaking half the order, and that's a real waste of time and material. So for simple stainless brackets, I still believe in a CMM check on the first one, @julia_anderson, because it forces you to face the numbers instead of relying on a gut feeling that might be wrong.
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