In the last months, in the company where I'm currently working, we've updated our PC-DMIS software to one of the newer versions (2018 R1), and have found a new possibility to report sizes with all the ISO modifiers integrated. For us this is great news, since now we can apply the modifiers directly on the measure rather than through the elements construction.
Doing so, we've found that using the "enveloppe" requirement, that for an external diameter should grant the GN for the USL, and LP for the LSL, gives the same result as demanding each modifier separately (which is good), however, the GN hands a different value than when constructing by Best Fit & Min Circumscribed cylinder (same points, same element, by scanning and then constructed).
and then demanding the diameter through the loc feature
We observed that the result is the same regardless of alignment, we also observed that the Mean Squares and GG modifier result on the same diameter (which is at is should be).
We tried the same idea with the GX diameter, and a Max Inscribed Best Fit Cylinder, and the problem is reproduced. The value for diameter is different in a magnitude close to 0.01 mm.
I'd like to know which of our assumptions is wrong, (that a min circumscribed best fit cylinder should be equal to GN for example, or maybe the diameter calculation through the localization feature), and why is it wrong. Or, if it may just be a problem of our programming that can be solved.
As a bonus question, I'd like to know if the size feature with modifiers that I show in the first screenshot will be available for two parallel planes (or it already is and we didn't find how to use it correctly, which is certainly possible).
Thank you very much for the time taken to read this far.
Best regards,
Álvaro
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