My idea behind this project is to design a 12 degrees-of-freedom quadruped robot that folds into a 6cm diameter ball. This way the robot could both walk and roll. The trick is to divide the sphere into four and use these as the robot's tibia linkage. The rest of the leg's linkages need to fold into the same sphere.

The challenge of this project is to fit all the mechanical parts, 12 servo-motors, the battery and the pcb into a very small space.