Abstract: A plurality of identical modules are serially connected together with each module including a base plate and a top plate interconnected by a universal joint assembly so that the top plate is adapted to pivotally nutate around the base plate to describe a cone in space. An array of twenty-four electromagnets, sequentially energized in sets of three, are arranged in a ring around the periphery of the base plate. Selective energization of the eight sets of electromagnets causes the rim of the top plate to be magnetically attracted to the energized electromagnets. The tilt of the top pivot plate is detected and controlled over a range of 360.degree., thus permitting a series string of modules to assume any desired elongated configuration.