Update: Here is the CAD file for the newest version:
https://drive.google.com/file/d/0BzU...ew?usp=sharing. It accomodates either a single-cim or cim+minicim input. If the extra minicim is used, the speed can be bumped up by increasing the top pulley size. Weight per module is 8.92lbs with the minicim, and 6.58lbs without it. The STEP file contains the entire chassis, which weighs 32.22lbs without the minicims and 41.04lbs with the minicims.
These weights include all screws, washers, nuts, bearings, motors, pneumatics, encoders, gearboxes and clips in addition to the module itself. Pretty much everything except for settling dust and the 5mm HTD belts.
To address the belt wrap, I moved the tensioner in closer so that a minimum of 5 teeth are in contact at any given time. I know this is below the recommended 6, but it's 5mm HTD so a decrease in capacity isn't bad at all.