Measuring GD&T to Datum System that is not fully constrained.

[[le...]]

Hello, I'm needing help with measuring some GD&T to Feature Control Frames that are not fully constrained. As an example if I want to tolerance a Profile in reference to Datum-A which is a plane. I am able to make a Datum System just to Datum-A and tolerance the profile to that Datum System. But the measurement on the Profile changes depending on what Global Alignment I have active (Best Fit, RPS, etc...). So I'm assuming I have to make a Global Alignment that matches the Datum System, but I'm not sure how to make one that isn't fully constrained. Any help would be appreciated.

[[Ch...]]

Theoretically, the result should not depend on the alignment. Two things could have gone wrong:

-The actual datum element A or the checked surface (or both) do not have a "required alignment" set, so their actual point selection depends on the alignment and, consequently, also the results. You can check this under "General" in the "Properties" tab.

-If the "required alignment" was set then the calculated fit runs into different results when starting from different alignment. This should not happen and we would be interested in the project in this case.