Adding a Relation to a Point

Lou, don't use a point use a coordinate system. Then assemble the C part to the CSYS and then create an analysis feature that will updat the CSYS to the latest CG information. CG is one of the options i the analysis feature, you need to dig kind of deep

Hope this helps, Glenn |B

Glenn thanks for the information. I needed the point on the CG to show its location in 2D so i could dimenion it. but thanks again for your help.

Lou, First you need to calculate mass properties using >edit >setup

'source' should be set to 'Geometry and parameters' , then click on >generate report.

Next, create a coordinate system using the default csys as reference, then create a relation in the assy with the three dim's which referenced the csys. It should look something like this:

d66=mp_cg_x ("","ASM_DEF_CSYS","") d67=mp_cg_y ("","ASM_DEF_CSYS","") d68=mp_cg_z ("","ASM_DEF_CSYS","")

When you regen the model the new coord sys will update. Each time you change the model you need to recalculate the mass prop using the generate report as above. Then a regen should update the coord sys., you can add a point to the new coord sys if you need a point. This seems like alot but a couple of mapkeys and your done quickly. Goodluck,

Gary Miglionico

You're right, this is the classic approach to representing, in a more permanent way, the center of mass in a model/assembly. And it works, but not very well. Without some trickery on the user's part, it is always representing the COG as it was with the previous part added, not the latest.

Here's why: adding a part causes a regen which moves the CSYS (or point) to the last (previous) position calculated by Generate Report. Now, you actually need to regen, again, but nothing happens automatically. You have to remember to do it. And if you don't, the position is NOT updated.

And, it is completely ineffective in part mode. There you add or subtract a feature; part COG does changes to the value calculated last by Generate Report. But after that, there is NO FORCED REGENERATE to get it up to the value of the latest Mass Prop. That's one reason they dumped the form embodied in the relation d66=mp_cg_x ("","ASM_DEF_CSYS","") and went to PRO_MP_CGX because it would automatically update without the manual 'Generate Report'. This is available in later revs of Pro/e, from about Wildfire on. BUT, the best of all possible worlds, I repeat, is the Analysis Feature. You have to buy Behavioral Modelling to get it, but you'll be a better person for it.

David Janes