PLEASE HELP!! (Display the PRINCIPAL AXES of an object in PRO/E )

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

Reply to
Roza.Mahmoodian
Loading thread data ...

One easy way I have found to do this is to suppress all features and insert a CYS. It will automatically be inserted at the principal axis of the part. The resume all.

Doug

Reply to
Doug

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

You did a model analysis which showed you the resultant coordinate system. Wouldn't it be nice if you could just save this csys as a feature, one that would update as you added other featurtes to the model? Well, you can. After you've run your model analysis, look for a check box that says 'Feature' and select. Click on the eye glasses to run this analysis. Then click the Feature tab and select on of the Datums check boxes ~ coordinate system or point center of mass. This will ensure that the cog exists in the model and remains displayed. When you hit the ckeck mark (OK), you'll see a feature called MASS_PROP_X in the model tree and a coordinate system/point at the center of mass. This is the one you want to use for your principal axes.

David Janes

Reply to
David Janes

Hi Doug,

Thanks for your response. I tried this but it didn't work because I was asked for the origin of the new system and my only option was to pick the older system's origin. Can you elaborate on this? I may have misunderstood you.

Roza

Reply to
Roza.Mahmoodian

Hi David,

Thank you! I just tried this, and I am so excited because this is exactly what I needed to do. You're a life saver!!

Roza

Reply to
Roza.Mahmoodian

Hi David,

Thank you! I just tried this, and I am so excited because this is exactly what I needed to do. You're a life saver!!

Yeah, before it was a little more obvious because it was located under Model Datums and was called an Analysis Feature. So, this is an old ability with a new twist: being able to create the analysis feature within Analysis. I think it's actually quite brilliant, but a little obscure. (Before that, you'd print out the Model Analysis data and use it to create an offset csys.) Don't remember how I discovered it, but I have forgotten and remembered it a couple times since. Good you lived, don't die for Pro/e or engineering. It's just a way to make a living.

David Janes

Reply to
David Janes

replying to David Janes, RAJAT KASLIWAL wrote: can you please share the short video of this??

Reply to
RAJAT KASLIWAL

replying to David Janes, RAJAT KASLIWAL wrote: can you please share the short video of this??

Reply to
RAJAT KASLIWAL

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.