Center of mass

[05735620d]

In pro/motion, how can I define center of mass?

 

[jabbadeus]

I don't understand what you mean.


Are you using Mechanica Motion or Mechanism Dynamics?


And what do you want to define center of mass for? Or are you interested in finding out the center of mass of a part or assembly? Or assigning a center of mass to an object and changing the model such that its COG matches where you want it to be?


The question as you phrase it is unclear.

 

[05735620d]

Oh sorry, I was not clear eough!

I would like to find out the center of mass of a assembly.

I am using Mechanica Motion

 

[jabbadeus]

You don't need Mechanica Motion for that, Standard Pro E will do that.
Go to Analysis > Model Analysis and choose Assembly Mass Properties
from the drop-down list.

 

[05735620d]

Great! I have tried it already! Thank you~

But how can I select that point(center of mass)? Or make it as a datum point, is it possible?

 

[jabbadeus]

If you have BMX, you can create a Datum Analysis Feature that creates either a coordinate system or a datum point at that location.


If not, you can create a datum point offset from the default coordinate system, then write relations of the form:


d17 = mp_cg_x


d18 = mp_cg_y


d19 = mp_cg_z


where d17, d18, and d19 are the symbolic forms of the dimensions for the x, y, and z offsets for the datum points.

 

[slashct]

As David mentioned the easiest is to create an analysis feature, good to move it to the footer.
Make sure when using therelations method is to make sure that you do a model analysis mass properties so that thesystem parameters are calculated, you can also use the same for a coordinate system instead of a point.