Hello! I am having this problem tricking Pro/E to give me a coordinate system that is set on the principal axes of an object. First off, is there a straight forward way for doing that? I couldn't find one. But here is how I tried to do it and it only worked ok partially:
I opened the object. Went to Analysis->Model->Mass properties. From there I could get the displacement and rotation between the object's coordinate system and the principal axes of it (by clicking on the "glasses" on the window that pops up). I kept this window on the screen to refer to it shortly after.
Then I went to Insert->Model Datum->Coordinate system. As the origin of the new system I picked the origin of the object's coordinate system. Then where I was being asked for offset values I put in the values I got from "CENTER OF GRAVITY with respect to the object's coordinate frame" from the previous step, and for the rotation value I put in the angles from "ROTATION ANGLES from object orientation to PRINCIPAL AXES".
You would think it would work, but it seems like I misunderstood something or I'm doing something wrong. This method places the new system on the object's center of mass, but the orientation of the axes is not right. I say this for two reasons: first, if you run the mass properties analysis again, the angles I used are not zero this time while they should be (the translation is zero though), and the second is that also visually they don't fall on the white set of axes that are displayed ( which I assume are the principal axes).
If you can help me with this I will really really appreciate it! Thanks! Roza