Final-Draft for the CAD! I added an extra bearing to hold the drive shaft. The sides are now riveted on, as opposed to bent from one piece. After creating a BOM, I found that 4 modules will end up costing about $750.
The entire module, from the top of the Timing-Belt pulley to the ground is exactly 7" tall. it is 2.65" wide, and 3.5" long.