Checking an expensive part on the CMM. I made a quick program because it was urgent. "Proved" out the program for moves and such. Ran the same part multiple times. CMM reports a large deviation on a critical diameter along a taper and everyone was scratching their heads trying to figure out what went wrong. Management almost conceded to scrap that part. I was asked to re run it again just to make sure and I find a point out of place on my cone construction. It just took 1 apple to run the bunch. Point was accidently taken in a tiny grease hole and I didn't foresee. I used paste and pattern and didn't think twice about it. I re-ran the part and the diameter is nominal, $40k part passed. I'm a genius and an idiot.
Not too many years ago (about 10) I missed an email in a string of about 15-20 emails back n forth between our QE and the SQE on a GD&T callout. That missed email was worth about $150k in parts not meeting the "last change" on the drawing. I was sweating bricks and made myself sick over it for about a month and I dreaded walking into work every day, I told the boss I was leaving over it and he wanted to know why it bothered me so much that it would get to this. I was miserable and he told not to worry about it.... He did tell me that the customer SQE had accepted a deviation on those parts a couple days earlier because even though they didn't meet the intent of the drawing they still functioned perfectly.
It happens more than most want to admit. Take it as a lesson and learn from it
louisd Working in the medical for the last 16 years has proven to see exactly how idiotic this line of thought is. I truly believe they are over engineering and creating tolerances that are directly responsible for the escalating cost of health care here in the US. Tolerances that have been cut from +/-.015mm to +/-.005mm is ridiculous and add s to the cost. Is our body going to feel a 0.5mm difference in the form of a medial condyle on a knee replacement? Or a 0.25mm shift in the hip socket? When they cut the "AP box" for a knee replacement are they that accurate with the bone saw?
louisd Working in the medical for the last 16 years has proven to see exactly how idiotic this line of thought is. I truly believe they are over engineering and creating tolerances that are directly responsible for the escalating cost of health care here in the US. Tolerances that have been cut from +/-.015mm to +/-.005mm is ridiculous and add s to the cost. Is our body going to feel a 0.5mm difference in the form of a medial condyle on a knee replacement? Or a 0.25mm shift in the hip socket? When they cut the "AP box" for a knee replacement are they that accurate with the bone saw?
