[EricH]

Originally Posted by RMS11

After our rookie season, we decided to take on building a crab drive. It has taken us a while since none of us knew inventor, it is also fairly primitive. The sprockets used to connect the wheel modules are missing, (they refused to go parallel with each other...) and there is no chain or screws yet. We would like some feedback on our design. Pictures are posted on http://s296.photobucket.com/albums/mm173/rshanor/
Thanks

Regarding the sprockets...

Constrain them using the "flush" constraint. That should get the connecting sprockets coplanar/parallel to each other. Then mate them to the wheel assemblies.

So far, it looks good; I'm a little puzzled why there is a ring around the wheel. Is it to provide a rotational platform?