THE CIRCULAR CLOVERLEAF ROBOT

Robots have actually been juggling for a while, but this robot, the Circular Cloverleaf, is designed to do it as simply as possible. There are no sensors, no scanners, no way to measure the pressure or see a ball going astray

http://uproxx.com/gammasquad/2015/06/watch-a-robot-juggle-four-balls-using-nothing-but-physics/