Wow, it’s been a long time! But in an ongoing effort to avoid studying and homework, I'm mucking about with the Ichibot and associated pages.
Even though I haven't gotten very far with Ichibot, I’ve decided to build a new, better mechanical platform for it. I’ve designed the chassis, and am currently looking for way to get it machined. I’ve also purchased the necessary hardware, pictured below (click the images for a larger version, or the links for a huge version).

Bearings, shafts, collars, pulleys, belts, motors Hardware partially assembled
Full-sized image of separate parts Full-sized image of partially assembled parts

Full-sized image of separate parts Full-sized image of partially assembled parts
The new Pittman motors (part GM8724S021-R1) are much better than the old JameCo motors. They are 12 VDC motors with 60.5 : 1 reduction gearheads and 500 CPR encoders. They were $195 each, and I’m a little concerned that I ordered too much gear reduction. Some people on the robotics lists have all suggested I’ll be happy to have the torque, and that the output shaft speed is sufficient. We’ll see.
The new chassis will look something like this. I need to redo the CAD. I’ll post complete drawings and make the files available.

CAD view of new chassis
Underside of new chassis