C.G. of assembly of eom assemblies 1

[Jm_E]

I am using NX10 and am trying to determine the c.g. of an assembly consisting of homogenious parts and eom assemblies.

I can assign a material to the homogenious parts. The oem assemblies consist of several parts in the model and I can assert a weight for the oem assembly model. I am just using the volumetric center of the oem assemblies as their size is small relative to the parent assembly.

Now the problem is how do I find the c.g. of the entire assembly? If I use the Measure Bodies tool I can only select the bodies in the assembly and not the oem assemblies with the asserted weights. I cannot not select the sub-components of the oem. Thus the tool is including the volumes of the oem components.

Anybody have a solution?

 

[Mukundh]

Try Using Menu Analysis->Advanced Mass Properties->Advanced Weight Management.

 

[Jm_E]

Yes, I used the Advanced Weight Management to assign a weight to the sub-assembly. Now the issue is when I want to then determine the resulting weight and cg of the parent assembly how do I do that knowing that the parts in the sub-assembly are ignored and the assigned weight and location of the sub-assembly is used? The parent assembly is quite large and selecting or de-selecting piece parts would be pretty tedious and time consuming. Are there some functions in the Advanced Weight Management command I'm overlooking?

 

[Toost]

IF you have asserted mass , CoG etc, you MUST calculate using the Advanced Mass Properties.
Using the "measure bodies" WILL NOT honor asserted values.

"Menu Analysis->Advanced Mass Properties->Advanced Weight Management." + Calculate xx.


Regards,
Tomas

 

[Jm_E]

Ah, this is helpful. I created a test assembly with a couple of homogeneous parts and two sub-assemblies. I specified the material of the homogeneous parts and asserted the weight of the sub-assemblies. I used the Advanced Weight Management and selected "Work Part" in the calculation section. The result agrees with what I find by adding up the weights of the parts by hand. So it appears to ignore the sub-assembly children when I assert the weight of the sub-assemblies.

Do you know how to make it put an indicator at the location of the c.g. or do I have to just use the x, y, z, results and place my own indicator?

Thanks,
Jim