Abstract: Apparatus and methods for precision control of degree of socket rotation where desired degree of rotation exceeds about 360°. One embodiment of the apparatus includes a cam structure associable with an assembly for holding and driving the socket so that either forward or reversed rotation of the cam structure and the socket are coincident. The cam structure includes a circumferentially projecting cam face construct movable through a path of rotation and having first and second spaced stop surfaces oriented across the rotation path. A rotation limiting mechanism includes first and second units for limiting cam rotation in each direction of rotation. Each unit includes a barrier portion and an actuating portion, movement of the barrier portion into the rotation path initiated by interaction of the rotating cam face construct and the actuating portion.