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NX Assembly and center of Mass

Siemens Legend Siemens Legend
Siemens Legend

I received the folllowing question today:

 

How to find center of mass of an NX assembly?
I have tried 'solid properties check' and 'measure bodies'.

- - - -
Jerry Sarfati
Siemens PLM Software
5 REPLIES

Re: NX Assembly and center of Mass

Siemens Phenom Siemens Phenom
Siemens Phenom

Actually the...

 

Analysis -> Measure Bodies...

 

...function is the way to do that.  Just make sure that the 'Selection Scope' is set to 'Entire Assembly' and that the 'Assocative' option is toggled ON.  This will result in not only the creation of your typical Mass Property expressions, but also a Point object at the centroid of the Assembly.  And if you also toggle ON the 'Show Information Window' you'll get all of the mass property data in the listing window including the XYZ coordinates of the centroid.  Of course, you can also use...

 

Information -> Point...

 

...to get the XYZ coordinates of that 'centroid' Point obejct any time that you wish.

 

Also note that this Mass Property data (in the form of expressions), including the 'centroid' point, will update as the Components which make up the Assembly are moditied.  However, if new components are added to the Assembly, you will need to update the Body Measurement feature, adding the new Component(s) to the measurement.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA

Re: NX Assembly and center of Mass

Experimenter
Experimenter

Hi,

 

Could you please tell me how to get the coordinates of the center of gravity in expressions list?

Is that possible?

 

Thanks in advance for answering.

 

BR

Zeljko

Re: NX Assembly and center of Mass

Siemens Phenom Siemens Phenom
Siemens Phenom

Starting with NX 9.0 we've added a 'Measure Point' function which will return, as expressions, the X,Y,Z values of any selected Point, either an explicit point object or any selected Snap Point.  So using this new function, after doing the Measure Body which will result in a centroid 'point' being created, you select that point and you will now a set of expressions for the X,Y,Z values which will update whenever the model it changed and the Measure Body feature updates.

 

Prior to NX 9.0, there was no practical way to do this and get expressions which would update associatively.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA

Re: NX Assembly and center of Mass

Experimenter
Experimenter

In NX Go to Menu --> Analysis --> Measure Bodies.

 

Then select bodies and In Results Display select "Show Information Window". Listing window will open which contains all the body details.

Re: NX Assembly and center of Mass

Creator
Creator

I know this is an old thread, but there's a problem.

 

The method suggested does not work when some components have "Asserted Weights" assigned.

Any workaround to get to the CoG and ideally, associative as well?

 

 

Thanks and much appreciated.

"Just Testing The Waters"