Moments of inertia reported to a CSYS

[mmm3ro]

Hi guys,

I need to make a mass analysis for a robot assembly in UG NX3 but the analysis must be made refering to a Coord. Sys. located on a bracket. So at the end, the Center of Gravity and the principal moments of inertia must be reported from that coord. system I will pick in the assembly.

Thanks in advance.

 

[JohnRBaker]

While in the Assembly, just move the origin of the CSYS to the point of interest using the 'WCS Dynamic' tool and then under...

Analysis -> Measure Bodies...

...do a 'Select All' and then pick the 'Information' icon on the menu bar.

John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.

 

[potrero]

John,
Why isn't the moment of inertia information available in the drop-down menu? Why is it only available from the 'Information' icon?

 

[JohnRBaker]

The 'Drop-Down' menu previews ONLY those items which will be saved as parametric Measurements to the Expression system if you toggle ON the 'Keep Measure' option (the 'floppy' icon) before you select the Green check-mark to finish the task. The listing window was deemed more appropriate for the large amount of data being calculated with this function, particularly those results which are shown as triplets (that is they have 3 components to their answer).

John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.

 

[potrero]

It actually would be useful to have a parametric measurement of moment of inertia (one could specify which direction to calculate the value, etc...)

Is this possible?

 

[hudson888]

It is possible to position a point and a datum axis parametrically in model space and use those to snap you WCSYS to inorder to perform the analysis. This is I know not necessarily your specific desire but apart from being as close as you're likely to get it involves a point and a vector so to that extent improves on your original request.

Cheers

Hudson

 

[mmm3ro]

Thanks John, is working as you told me.