A general base to use for robotics projects etc. To keep the cost down it doesn't use any bearings. The tracks are assembled using Brad nails. The axles are 1/4" aluminum round stock from Home Depot. I'll get together a list of the remaining screws in a couple of days. http://youtu.be/FrggtWnwNds Update: Added Modified Side panel to direct mount the motor using Pololu Hex wheel adapter. Added modified sprocket that works with the Hex wheel adapter.You'll need to print 37 of each track pad (left,right) 74 of the outer pins, and 37 of the center guide. Repeat this for the second track. More to come.