Rev 2
Total weight per module is less than 8.4lbs.
Now with gears (24t:42t) connecting pivot motor/gearbox to pivot module. Pivot motor/gearbox is mounted next to the CIM and upside down. This all saves weight, part count, and space inside frame perimeter. Edit: this gets the motor leads away from the floor and removes the belt as a failure point.
Lower polycarbonate mount plate is pocketed for weight.
Pivot side plates are chamfered at the bottom and smaller on the sides.
Wheel uses 1/4in bolt as dead axial.
CIM motor is connected to a AMT103-V encoder in a fashion inspired by that posted by Twins Inc. of 2605 earlier in November (
http://www.chiefdelphi.com/media/photos/40928). This will save weight and space, as well as cost in our situation.
Module is now also 100% symmetrical (no left or right versions).
Thank you to asid for the suggetions.