My first ever 3D print project. Borrowed printer, leftover glow in the dark PLA for the frame, and no idea what I'm doing. It works though... simple hobbyking wifi 4 channel receiver and it is driveable with 4 AA batteries and my phone using the provided app on android (also works on ios). I used lock nuts on the 5/16" axle shafts and roller blade bearings in the clamshell gears. My friend printed the ABS tracks. I was thinking of putting the arm from the caterpillar excavator project on top, but ended up building something else with it. I used parts from several sources for the higher servo arms to put on a top plate, segmented frame so it would fit on my 3d print bed.
I learned a great deal on this print most having to do with rafts and getting the print to stick to the bed. Some parts came off the bed and are warped including the servo mounts.