This is a lego compatible brick for use with lego mindstorms robo. This frame can be substituted for around 90 pieces of the rover, and connects the controller with sensors, motors, and wheels.
Update: I posted a video of the robot in action: https://www.youtube.com/watch?v=_xZMclCDFmU
I sliced with slic3r, and printed on a prusa mendel using pla. The file is in mm.