I've been trying to do a comparison of these two tracks, witha block sliding along simulating a vehicle. The circular trackworks fine, and I got the applied force to stay parallel to thevehicle. The constraints are fine. The results (velocity,acceleration) are correct.

The second one, with a parabolic track works okay until I add theforce. Then it barfs and says it has redundant constraints. It'sset up just the same. Can anyone get this to work?

I'm using SW 2008 SP5 with COSMOSMotion 2008.

Thanks,
DerekSolidworksMotion Studies