pic: GUS Team 228's Prototype Sheet Metal 6WD Chassis

[artdutra04]

Originally Posted by topgun

I drew up a model similar to your 2008 model. One of the questions I had in doing that are what are the pros and cons of putting the chains on opposite sides of the driven center wheel versus having both on the same side? I would think having them on opposite sides of the center wheel would be easier, but then is there a mechanical reason for having them on the same side.

Putting the sprockets on the same side (inside) adds almost an inch to the lateral wheelbase of the robot. This slightly improves turning by moving the angle of the wheel relative to the center of turning closer to perpendicular, which allows for a greater percentage of the wheel's tractive force to be used in the desired direction rather than "wasted".

Originally Posted by topgun

Looking at this model, why did you go with squares instead of triangles for lightening?

Our sheet metal shop sponsor that fabricates our drive base uses turret-punch machines for their work. Slotted pockets are easy to punch out (punch two or four holes, then use straight punch to connect them). Triangular pockets require a lot of nibbling to make, which slows down the fabrication time. Since their time and work is donated, I like to keep the production time to a minimum.

Edit:

Originally Posted by czeke

What was the total weight, with the upper mechanism ?

There is no upper mechanism on this model, only a drivetrain and base chassis.