Vex robotics 406 4205 forkllift ball machine by hexbug vex 406 4205 p the vex reg robotics fork lift ball machine by hexbug reg teaches important scientific lessons in kinematics linkages reciprocal motion timing and its effects on an overall system p p using a unique over centre linkage this sophisticated machine is capable of executing both a scooping and lifting motion with its specialized forklift arm powered by a hand crank the machine will move balls in a continuous loop at