[Da...] Posted March 24, 2022 Share Posted March 24, 2022 We have a shaft about 9 inches long. On the end of the shaft there is a bore with a tru-position callout to -A- (the shaft) of .00196". I was called on Saturday at 8:00 AM by my panicked boss..." I can't do this! What am I going to do !! " . I told him to put the part in a vee block locating on the shaft and indicate the bore, It should be less than .00196". Twenty minutes later the owners son says we NEED to Check tru-position !!!. So on Monday I fire up and check it with the micura. Add a max material condition per print and look at the print out. So how does adding MMC change my actual value????Capture.JPG Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/ Share on other sites More sharing options...
[Ri...] Posted March 24, 2022 Share Posted March 24, 2022 The .(M) is not the Position result, but merely a statistical value used to display tolerance usage for capability analysis. You cannot calculate capability on a tolerance with a material boundary because every part has a slightly different tolerance. That is why it is converted to a percentage of tolerance usage. If you take the result of 0.000534 and divide it by 0.002368 you get .2255 or 22.55%. If you take the .(M) result of 0.000444 and divide it by 0.001969 you get 0.2255 or 22.55%. At the end of the day, you can disregard the .(M) result. There are multiple posts on the forum on how to remove it from the printout. Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51874 Share on other sites More sharing options...
[Je...] Posted March 24, 2022 Share Posted March 24, 2022 . What in the world are you making that has a nominal diameter of .629133" and tolerance of .00196" instead of .6291" and .00195"? What's the uncertainty ratio of your Micura? Jeff Frodermann Meier Tool & Engineering Brooklyn Park, Minnesota . Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51876 Share on other sites More sharing options...
[To...] Posted March 24, 2022 Share Posted March 24, 2022 Please sign in to view this quote. Technically, MMC shouldn't change the actual value. It should change the tolerance. Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51878 Share on other sites More sharing options...
[Ri...] Posted March 24, 2022 Share Posted March 24, 2022 It didn't. Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51880 Share on other sites More sharing options...
[To...] Posted March 24, 2022 Share Posted March 24, 2022 Please sign in to view this quote. You talking to me? If so, the tolerance changed from .00196 to .00233 Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51882 Share on other sites More sharing options...
[Ri...] Posted March 24, 2022 Share Posted March 24, 2022 Please sign in to view this quote. That's the .(M) which isn't the actual result of the position. Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51884 Share on other sites More sharing options...
[To...] Posted March 24, 2022 Share Posted March 24, 2022 Please sign in to view this quote. I don't think Dave was referring the (M) in his original post. Maybe he was. He just wasn't clear with his question. Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51886 Share on other sites More sharing options...
[Da...] Posted March 24, 2022 Author Share Posted March 24, 2022 [/quote] I don't think Dave was referring the (M) in his original post. Maybe he was. He just wasn't clear with his question. [/quote] That was what I was talking about, and the answer is good. BUT, I get frustrated when they don't understand that not EVERY stinking thing has to go thru our CMM's . The tir check was sufficient. stop calling me on my days off ! 😠 😠 😠 🤣 Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51888 Share on other sites More sharing options...
[Je...] Posted March 24, 2022 Share Posted March 24, 2022 Please sign in to view this quote. . Come on, Dave. Aren't you a team player? Don't you feel valued when your team looks to you for help? Jeff Frodermann Meier Tool & Engineering Brooklyn Park, Minnesota . Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51890 Share on other sites More sharing options...
[Da...] Posted March 25, 2022 Author Share Posted March 25, 2022 TEAM ????? 🤣 🤣 🤣 🤣 🤣 🤣 🤣 🤣 Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51892 Share on other sites More sharing options...
[Cl...] Posted March 25, 2022 Share Posted March 25, 2022 There is no "I" in team, but there is an "M" & an "E". Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51894 Share on other sites More sharing options...
[Jo...] Posted March 25, 2022 Share Posted March 25, 2022 Please sign in to view this quote. T ask E veryone A ssigned M e Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51896 Share on other sites More sharing options...
[Da...] Posted March 25, 2022 Author Share Posted March 25, 2022 Teams allow the blame to be spread more thinly ! 😱 Link to comment https://qualityforum.zeiss.com/topic/10736-why-do-they-do-these-things-tru-position/#findComment-51898 Share on other sites More sharing options...
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