I have a part that uses 2 cylinders as a common datum. There are multiple features positioned back to the common A-B datum. Using the default math algorithm and the simultaneous tolerance command I get all but one feature to pass. This feature is a diagonal through hole that is controlled in the X direction by a linear dimension and then in Y and Z by the cylindrical datum. Now if I change the datum math to least squares on just this feature it gives me a very good position. I am assuming this is not the correct way unless I change all the other related features to least squares datum math as well. But if I do the other features that were really good position wise with the default datum math now were failing.
I didn't mention that the 2 common datum cylinders also get ground to their final size later after the complete part is made.
Just wondering what you all think would be the best way to evaluate these features and if you can just have least squares math for one but default for the rest of the related positions.
Thanks all.
