[To...] Posted January 25, 2023 Share Posted January 25, 2023 I'm thinking a can create a Geometry Best Fit Alignment on B and the use in a Surface Profile of the plane to the GBF alignment. Do I need to include A somewhere in the calculation to validate the basic dim?Screenshot 2023-01-25 083710.jpg Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/ Share on other sites More sharing options...
[Cl...] Posted January 25, 2023 Share Posted January 25, 2023 Maybe the drawing is incorrect and should call out A & B? Aren't they really asking for perpendicularity to -B-? Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39784 Share on other sites More sharing options...
[To...] Posted January 25, 2023 Author Share Posted January 25, 2023 Please sign in to view this quote. There is a good possibility the drawing is incorrect because else where on the part, they call out a surface profile with MMC. But at this point I can't prove that's wrong. I agree that it is appears to be in the perpendicularity family, or maybe even the position family because of the basic dim. Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39786 Share on other sites More sharing options...
[Ro...] Posted January 25, 2023 Share Posted January 25, 2023 Unless -B- is a cone, it can't constrain the location of the plane callout. The plane is free to slide up and down the axis of -B- as a best fit, making -B- inconsequential. MMC on profile is not allowed. Profile is a surface control, not a feature of size. Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39788 Share on other sites More sharing options...
[To...] Posted January 25, 2023 Author Share Posted January 25, 2023 Please sign in to view this quote. Wouldn't the tolerance zone be defined as two parallel planes, perpendicular to B, .xxx apart, centered by basic dim? So, as long as the sliding along B would allow all of the points to fit within the zone, it passes? Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39790 Share on other sites More sharing options...
[Ro...] Posted January 25, 2023 Share Posted January 25, 2023 The tolerance zone of -B- itself is 2 perpendicular planes on the axis of the hole. The axis constrains 4 DOF. It can rotate and it can slide along the axis. So the callout doesn't make any sense to me. If they want the location of the plane relative -A-, then that makes sense. Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39792 Share on other sites More sharing options...
[To...] Posted January 25, 2023 Author Share Posted January 25, 2023 Please sign in to view this quote. I thought the same thing but that would assume that A was important to the orientation of the features. Hypothetically speaking, what if the part rotated about B and it was important to keep the feature at the same axial location along B. I have no idea how this part is used but just trying to justify the designer's reason for calling something out like that. Also, what is the problem with axial degree of freedom on B being allowed to do a best fit? The best fit is going to be applied to the nominal feature defined with basic dimension. Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39794 Share on other sites More sharing options...
[Ro...] Posted January 25, 2023 Share Posted January 25, 2023 I get what you're saying. -B- would indirectly control the form/orientation as a best fit to the axis, but not the location. The problem is that since there is no location, the surface itself could be like a ramp that goes up and down along the axis of -B- and is not flat. As long as the surface was within the profile tolerance controlling it's form and orientation, it could fluctuate along the axis. So, I guess it's possible, but as Clarke stated, perpendicularity seems more reasonable. Even position, runout, etc. would make more sense to me. Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39796 Share on other sites More sharing options...
[To...] Posted January 25, 2023 Author Share Posted January 25, 2023 Please sign in to view this quote. Yes, I know it is not allowed. My post was not written well. There is a good possibility the drawing is incorrect because else where on the part, they call out a surface profile with MMC. But at this point I can't prove that's wrong. I should have said I can't prove that it's wrong. There is a good possibility the drawing is incorrect because else where on the part, they call out a surface profile with MMC. Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39798 Share on other sites More sharing options...
[Ro...] Posted January 25, 2023 Share Posted January 25, 2023 I know you knew that, Tom. This is why I like talking to people in person. I don't translate well to the internet/texting environment. My thought process is rather volatile and unpredictable. 🤣 Please know this... Whenever I post, 99% of the time I'm trying to convey information, not attitude. Please don't take my ramblings personally. 🙂 Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39800 Share on other sites More sharing options...
[To...] Posted January 25, 2023 Author Share Posted January 25, 2023 Please sign in to view this quote. LOL I just wanted to point out that I actually knew something. No offense taken. You bring a lot of useful knowledge to the forum Link to comment https://qualityforum.zeiss.com/topic/8810-surface-profile-without-freeform/#findComment-39802 Share on other sites More sharing options...
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