[Cl...] Posted May 6, 2020 Share Posted May 6, 2020 I have 4 T/P characteristics, one of them uses both datums -A- & -B-. The other 3 use just -A-. Datum -A- is a cylinder. Datum -B- is a .090 thick segment of Datum -A- (imagine slicing the cylinder straight down the center lengthwise in 3rd's). The center 3rd is Datum -B-). Both -A- & -B- are allowed MMC. When I use -A- by its self to evaluate a circle feature MMC is highlighted. If I use -A- & -B- together, MMC won't highlight. What gives here? In addition, if I have to use a symmetry plane for -B-, because MMC is allowed. So, if I pull in just -A- to evaluate the symmetry plane (-B-) the MMC option for -A- won't highlight? Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/ Share on other sites More sharing options...
[Me...] Posted May 6, 2020 Share Posted May 6, 2020 Are you using View Tolerance as your best fit type? Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86912 Share on other sites More sharing options...
[Cl...] Posted May 6, 2020 Author Share Posted May 6, 2020 Not sure what you are talking about? "View Tolerance"? Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86914 Share on other sites More sharing options...
[Ma...] Posted May 6, 2020 Share Posted May 6, 2020 When you say "-A- & -B- Together" what do you mean exactly? Is it a compound datum like |A-B| or primary|secondary like |A|B|? Other than being more confusing, I can't see how either would differ from simply using |A| on its own. Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86916 Share on other sites More sharing options...
[Cl...] Posted May 6, 2020 Author Share Posted May 6, 2020 -A- primary, -B- secondary. Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86918 Share on other sites More sharing options...
[Ri...] Posted May 6, 2020 Share Posted May 6, 2020 Please sign in to view this quote. He is referring to using a 2d Best Fit Position evaluation. If you use a 2d Best Fit Position evaluation, you have to change the evaluation type to View Tolerance to be able to apply material modifier to datums. Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86920 Share on other sites More sharing options...
[SH...] Posted May 6, 2020 Share Posted May 6, 2020 Please sign in to view this quote. I smell a rat in your printout, what is the meaning of using same axis as two datum,how we can control the orientation location using same axis as datum. MMC called for the four circle or the datum A and B?.if it is called for the datum, it should be MMB maximum material boundary. I think you are worried about the datum shift,MMB. If you add MMB or not it will not affect the true position output. If you don't mind can you attach your drawing?? Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86922 Share on other sites More sharing options...
[Cl...] Posted May 6, 2020 Author Share Posted May 6, 2020 I have never used this option? Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86924 Share on other sites More sharing options...
[Ma...] Posted May 7, 2020 Share Posted May 7, 2020 Please sign in to view this quote. So, according to your description of -B- as a portion of -A-, -B- is superfluous, because all of the available degrees of freedom are already controlled by -A-. Just use -A- for primary datum. Leave the rest blank or use -A- for all elements of the datum structure if you like. Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86926 Share on other sites More sharing options...
[Cl...] Posted May 7, 2020 Author Share Posted May 7, 2020 That is what I'm doing. The GRR is failing. Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86928 Share on other sites More sharing options...
[Ri...] Posted May 7, 2020 Share Posted May 7, 2020 Please sign in to view this quote. What kind of tolerance are we talking about here? Is this on your O-Inspect? Have you looked at the GR&R on the individual axis to see if one is moving more than the other? Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86930 Share on other sites More sharing options...
[Cl...] Posted May 7, 2020 Author Share Posted May 7, 2020 .004 Surface profile. Contura G2 (RDS/XXT.TL1) The feature is a 6 sided peg. I tried scanning the six planes and recalling the points into a FFS. I also tried sectioning the peg in 7th's, around the OD, then creating seven 2d curves and recalling those points into a FFS. I get a greater deviation with this method, and have not had time to run the type 1 again with the change. Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86932 Share on other sites More sharing options...
[Ri...] Posted May 7, 2020 Share Posted May 7, 2020 Free-Forms are tough, man. There is no filtering, and/or outlier elimination. At least with a Curve there is the ability to do that. Shoot me a PM if you want, and I can take a look at your program if you'd like. Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86934 Share on other sites More sharing options...
[Me...] Posted May 7, 2020 Share Posted May 7, 2020 Please sign in to view this quote. Clarke, Calypso does not allow MMB to be applied when a symmetry plane is used as the datum feature or being evaluated as the considered feature. Link to comment https://qualityforum.zeiss.com/topic/15856-drf-amp-mmc/#findComment-86936 Share on other sites More sharing options...
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