[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 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 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 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 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 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 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 Share on other sites More sharing options...
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