[Dave McLaughlin]

What I meant by 3x3 casing is that the housing for the wheel is made from 3"x3" (1/4" W) aluminum extrusion with a piece of 1/4" sheet welded to the top to form a rectangular prism with an open bottom. I placed the sprockets on the outside to both reduce the height and width of the casing in an attempt to save weight. I believe Team 1625 did something similar in 2K8 and I moved the sprocket outside based on advise of one of their members.

The module is steered by a sprocket mounted above the upper bronze bushing. It is not show as it is part of another assembly.