Good morning all,

I am trying to create a tank tread that will actually move along a specifed path.  I have pulled an example from an old tutorial that mates sketch points of a "tread part" to a spline path.  I can do this with no problem.   I mate a fixed plane of the part with a fixed plane to keep the "tread part" perpendicular to the path, then mate the parts to each other and then to the path.  This all works just fine untill I start to move the tread parts along the path.  They move but they will flip over top for bottom and flip back on themselves over other parts in the chain.  The example only has a few tread parts included but you can see what and how, but I can't figure out the why.

I have read the chain threads and the mate flipping threads here and have learned a lot but as of yet have found no way to stop these treads from dancing around like a school boy on his first date!  Does anyone have any ideas or suggestions on how to fix this?  It's just a project I'm working on for fun but it's driving me nuts.

Thanks in advance for all the help.

Drew