Basebot -- Drive (deprecated)
Basebot (deprecated)
Basebot with Touch LED (deprecated)
Basebot Stand (deprecated)
Basebot Pusher -- Finger (deprecated)
Basebot Pusher (deprecated)

Basebot v2 -- Drive
Basebot v2 -- no Bumpers
Basebot v2
Basebot v2 Stand
Basebot v2 Pusher -- Finger
Basebot v2 Pusher (fixed, 4")
Basebot v2 Pusher (variable, 3-6")
Basebot v2 Gripper -- Single Finger 
Basebot v2 Gripper -- Double Finger
Basebot v2 Gripper

Mechanism -- Compound Gear

Skidsteer v2 -- Drive
Skidsteer v2 -- Base
Skidsteer v2

Skidsteer v3 -- Base
Skidsteer v3 -- Arm added
Skidsteer v3 -- Brain, Battery, and Limit Switch added
Skidsteer v3 -- Rotation Sensor added

Compound Gear study
Motor and Rotation Sensor study