topic Re: Principal Axes Rotation Angles in 3D Part & Assembly Design

Principal Axes Rotation Angles

gpommeranz — Wed, 04 Jun 2025 14:51:48 GMT

I have a mass system that I am designing isolators for. I'm attempting to create a new coordinate system that represents the principal axes so that I can use that to identify locations and angles for the isolators. My problem is that when I compute the principal axes, then create a new coordinate system at the location and orientation of the reported principal axes, the location is correct but the rotation is slightly askew and I can't figure out why. In the picture below, I would expect my 1, 2, 3 axes and X, Y, Z to be on top of each other. I uploaded the CAD files as well.

Re: Principal Axes Rotation Angles

StephenW — Wed, 04 Jun 2025 15:09:58 GMT

I have had trouble when translating and rotating coord sys in one csys. I will break it up in to translation for a 1st csys and a 2nd csys for rotation.

Not sure if this will help you or not.

Re: Principal Axes Rotation Angles

gpommeranz — Wed, 04 Jun 2025 16:26:56 GMT

Thanks, I tried that but still got the same results with the axes slightly askew.

Re: Principal Axes Rotation Angles

tbraxton — Wed, 04 Jun 2025 16:50:23 GMT

Have you reviewed this document yet? If not check out the process needed to get you to the target.

Article - CS33398 - After having entered 3 values in >Orientation >Selected CSYS axes for rotation about X,Y and Z when creating a CSYS1 from another CSYS0, orientation of CSYS1 seems wrong in Creo Parametric.

Re: Principal Axes Rotation Angles

gpommeranz — Wed, 04 Jun 2025 17:24:30 GMT

That did it! Thank you very much! Rotating about a newly created axis makes a big difference of how the coordinate system ends up.

Re: Principal Axes Rotation Angles

gpommeranz — Wed, 04 Jun 2025 17:29:35 GMT

I meant to accept your answer as correct and accidentally clicked on mine.

Re: Principal Axes Rotation Angles

tbraxton — Wed, 04 Jun 2025 17:30:57 GMT

No problem, if you notify the moderators they can make the change.

Re: Principal Axes Rotation Angles

gpommeranz — Wed, 04 Jun 2025 17:32:01 GMT

Already sent. Thanks again!