Shrinkwrap CENTER OF GRAVITY

[slalwani]

It has been noticed by our department via model trials that shrinkwrap's Center of Gravity (CoG) differs from actual model CoG even though the solid feature is chosen when creating a shrinkwrap to maintain proper volume with proper weights. We create custom oilwell trucks and weight analysis is a big part of our design. Now i cannot put in full assemblies without shrinkwrap (slows down a lot and very cumbersome). Shrinkwrap is the only way my overall assembly seems workable. I was having my department implement model's weight analysis which inventor let me down. Is there any explanation to that?

Thanks

Summit

16GB Ram

3.8Ghz O/C Processor Intel Core 7

WinXP

IV2010

[slalwani]

Sorry, that should be WIN 7 not XP.

Thanks,

Summit

[cwhetten]

Shrinkwrap creates a single part file that is "derived" from an assembly file.  This single part file can only be of one material and, therefore, one uniform density.  If your assembly consists of components of various materials and, therefore, various densities, then there will be a discrepancy in the location of the COG between the full assembly and the shrinkwrapped part.

Because the idea of a shrinkwrap is to create a single part, there is no way of getting around this.  Use a different approach than shrinkwrap if you need accurate COG locations.

-cwhetten

[cwhetten]

Another issue with shrinkwrap is that, depending on your settings, it can fill in cavities in your model.  If these cavities are large enough, this will throw off the volume and mass of a model, and therefore yield a significantly bogus COG location.

-cwhetten