SET UP CG

A fellow Pro/e designer asked me today how to make a coordinate system into a center of mass (aka, CG). It was an assembly with uneven mass and a COTS part. He wasn't permitted to disassemble it and measure individual pieces ($20k warranty issue). So, he measured the actual CG in three axes (balance and measure, rotate, repeat), then created the coordinate system at that point as an offset CSYS in his model. He just needed to get model analysis to recognize that as the CG, something that model analysis couldn't do by itself.

It would be nice if trhere were a direct way to turn this offset CSYS into a CG, but it doesn't seem to exist. Instead, I told him the following: do 'Edit>Setup>Mass Props', click the Source window and pick 'Geometry & Parameters', then click the Edit button. Select the middle tab, Center of Gravity, and fill in the offset numbers. When done, this will create a CG recognized by model analysis.

David Janes

 

See, now this is a keeper. The forum's not dead yet!

Thanks, David!