Vex robotics 406 4202 robotic arm by hexbug vex 406 4202 p how do industrial robots the kind that are used on assembly lines actually work p p now you can unlock the secrets of these sophisticated machines by building one of your own the vex reg robotics robotic arm is a completely functional construction kit inspired by real industrial robot arms it is hand powered and can pick up and relocate items using four degrees of freedom and an articulated grabber hand the whole crane ca