Data storage libraries as disclosed that provide for accessors that turn upon angled rails. In the library, a first rail and a second rail form an angle. The first and second rail each have a drive surface, but the drive surfaces are on different vertical planes. A switching mechanism of the accessor is then configured to move a drive mechanism between the different vertical planes of the drive surfaces. If the switching mechanism positions the drive mechanism adjacent to the drive surface of the first rail, then the drive mechanism engages the drive surface of the first rail to move the accessor along the first rail. If the switching mechanism switches the position of the drive mechanism adjacent to the drive surface of the second rail, then the drive mechanism engages the drive surface of the second rail to move the accessor along the second rail.