[Cl...] Posted November 30, 2021 Share Posted November 30, 2021 I have a cylindrical part, about 80mm long. It has a 12 mm long x 7 mm Ø cylinder on one end and a cone transitioning to a sphere at the other end. The customer wants surface profile of both of theses features in one characteristic. Points from the two features recalled into a FFS. I've started a type-2 GRR. Several of my 30 runs have a strange result. The tolerance is 0.05 mm and the typical deviation is anywhere from 0.040 to 0.100. About five of the 30 runs output a deviation of 1.34 or so. If I do a subsequent evaluation they change to what they should be (0.040 TO 0.100). Any idea what's causing this? Link to comment https://qualityforum.zeiss.com/topic/11500-strange-output/ Share on other sites More sharing options...
[Er...] Posted November 30, 2021 Share Posted November 30, 2021 Are the features measured in the FFS? I've seen Calypso get ahead of itself before. Link to comment https://qualityforum.zeiss.com/topic/11500-strange-output/#findComment-56890 Share on other sites More sharing options...
[Cl...] Posted November 30, 2021 Author Share Posted November 30, 2021 No their recalled three other features, a cone/sphere & a cylinder. Link to comment https://qualityforum.zeiss.com/topic/11500-strange-output/#findComment-56892 Share on other sites More sharing options...
[Er...] Posted November 30, 2021 Share Posted November 30, 2021 I am no expert to FFS, but after recalling the points, did you select the surfaces used? Does this even Matter? Maybe you need to re-calculate nominal geometry??? TBH I'm not sure when to use these options, so just throwing it out there. With that being said I just finished a Type 2 study with profile similar to what you are doing and I didn't have a problem with what you are describing. Link to comment https://qualityforum.zeiss.com/topic/11500-strange-output/#findComment-56894 Share on other sites More sharing options...
[Ma...] Posted December 1, 2021 Share Posted December 1, 2021 It's not needed to select faces. But it's double-sided sword. When you select some faces and due part deformation and close to edges scanning path, you can end up with a few measured points outside of faces and strangely they add up to closest nominal face ( and make bigger deviation ). Perhaps when you don't select any of faces, Calypso will select it for you - but again when it's close to border of faces, Calypso can select wrong face ( rather not select ) and measured point can be outside of "selected" faces. If it's not this case ( simple cylinders, no corner radiuses with many faces ), then i am out of ideas. Link to comment https://qualityforum.zeiss.com/topic/11500-strange-output/#findComment-56896 Share on other sites More sharing options...
[No...] Posted December 1, 2021 Share Posted December 1, 2021 If I understood the original post correctly, he did a subsequent evaluation with the existing points, after which the result was correct. So if it'd be caused by points outside of a face, it should also happen in subsequent evaluation. Link to comment https://qualityforum.zeiss.com/topic/11500-strange-output/#findComment-56898 Share on other sites More sharing options...
[Cl...] Posted December 1, 2021 Author Share Posted December 1, 2021 I ended up re-building the FFS and the problem went away. Link to comment https://qualityforum.zeiss.com/topic/11500-strange-output/#findComment-56900 Share on other sites More sharing options...
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