Center Of Gravity

[mykeo]

Hi,

I am trying to find the center of gravity for my assembly I made and I found that if I go to

Analysis > Advanced Mass properties> Advanced weight management

I could figure out the center of mass

But I am a little confused by my findings. I did enter in all the relevant weight and density info for each part but the answers I get well I assume those are coordinates right? Where are they from the WCS, one of the parts,..I don't know?

So where are these coordinates from and how can I set them so I don't have to do every time I change a part to determine the COG.

I am also using NX6

Thanks for all the replies in advance.

Myke

 

[SDETERS]

NX should toss a point into the assembly at the Center of mass. NX 7.5 does I do not know about NX6

 

[mykeo]

Also what may also help is my assembly is a little tilted with respect to the triad axis and I would like to rotate the whole assembly so when I orient the view to "top" I actually see the top.

Thanks,

Myke

 

[JohnRBaker]

You can also use...

Analysis -> Measure Bodies...

...select all the Components. If the 'Associative' option is toggled ON this will give you not only a Point object at the 'Center of Gravity' but also a set of expressions for such things the Weight, Mass, Volume, Surface Area, etc. You will also have an option to generate a listing showing these same values as well as a lot more information about the spatial characteristics of your Assembly

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

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

 

[mykeo]

SDETERS- yes it does, so I decided to just use the assemblies> measure distance and record that distance on the draft but I can give an accurate measurement since my model is tilted, is there a way to tilt it around the triad axis.

John-I actually read that same post on another thread and thank you btw cause i was looking for that, that is what I used and selected for more info. I originally wanted where these dimensions were referenced from as it never states any of that so they were essentially useless to me, the CG at least, since I didnt know if they were referenced from the first part I clicked CG or the datum coordinate system or the triad axis or a random point 300 meters from my object that I forgot to delete.

So now I have the point located at the CG of the object, I am using the measure distance feature but my only grip is that my object is slighted off the axis I want it on in the drawing views. So if I just type the CG is so and so distance from this part in the x direction, the x direction is really the x direction 30 degrees rotated. So I am asking how do I rotate the assembly to match what i want to display and display a universal coordinate system for each view, Ill even settle on displaying a single universal coordinate axis for the sheet and just use multiple sheets to get my point across.

Thanks,


Myke

 

[JohnRBaker]

If your Assembly was created with only a single Component being 'Fixed' and all the others are properly constrained, then you should be able to just select that 'Fixed' Component and use...

Assemblies -> Component Position -> Move Component...

...and when the dynamic drag handles come up you can use them to move/rotate your Assembly in real space. Now if this Component is 'Fixed', you'll be asked if you REALLY want to move it (since it's fixed) and if you say Yes, then you can position the Assembly however you wish and the rest of 'properly' constrained Components will come along for the ride.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

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