1. IN A SELECTOR SWITCH, THE COMBINATION OF: A SHAFT AND MEANS FOR JOURNALING THE SHAFT; A ROTOR FORMED WITH A SWITCH ARM AND KEYED TO THE A SHAFT FOR ROTATION THEREWITH; A STATOR ELEMENT FORMED TO RECEIVE THE SHAFT AND HAVING A MULTIPLICITY OF ANGULARLY SPACED CONTACTS WITH AND DESIRED ONE WHICH THE SWITCH ARM IS TO BE REGISTERED; AND MEANS FOR ACCURATELY PERFORMING THE REGISTRATION, COMPRISING: A STATOR INDEX POSITIONED IN FIXED RELATION TO THE STATOR AND HAVING A RING GEAR FORMATION; A ROTOR INDEX FORMED AS A SPUR GEAR KEYED TO SAID SHAFT FOR ROTATION THEREWITH AND ADAPTED TO MESH WITH SAID RING GEAR WHEN THE SPUR GEAR IS IN AXIAL ALIGNMENT WITH SAID RING GEAR; AND BIASING MEANS FOR NORMALLY URGING SAID GEARS INTO AXIAL ALIGNMENT BUT YIELDABLE TO PERMIT AXIAL DISPLACEMENT OF THE SHAFT WHEREBY THE SHAFT AND SPUR GEAR CAN BE TURNED; THE GEARS BEING FORMED TO DEFINE ANGULAR POSITIONS OF REGISTRY BETWEEN SAID ARM AND INDIVIDUAL ONES OF SAID CONTACTS.