Vex robotics 406 4208 hook shot ball machine by hexbug vex 406 4208 p the vex reg robotics hook shot ball machine by hexbug reg teaches important scientific lessons in kinematics linkages reciprocal motion and potential versus kinetic energy p p spin the hand crank to wind up the elastic powered striker arm to launch balls through the loop system and sink them in the return basket once constructed this machine will move the balls in a continuous loop uphill at a rate of approximate