Error with Centroid of Measure Bodies calculation

[Barnon]

I'm designing and fabricating a driveway gate for my Brother in Law and I was using Measure Bodies to calculate how many counterweights to balance the load at the pivot point. You can see in the second pic below the Centroid with Measure Bodies is very close to the pivot point. At fabrication it took 8 less 1/4 thk weights, than calculated, to actually balance the load. Seems like quite a error somewhere. All parts are steel and wall and plate thickness are correct. I've attached a parasolid file in case anyone can tell me what I'm doing wrong. I'm using NX 9.

Thanks for any help.

 

[3DDave]

Try seeing what small changes in wall thickness do to the centroid location.