Abstract: A brushless DC motor-driven spindle assembly for a textile ring spinning frame wherein a shaft for rotatably supporting a bobbin for yarn collection is mounted for rotation about a central axis of rotation in a bolster section and, under certain conditions of operation, for rotation about axes which are incrementally angularly displaced from the central axis of rotation, and including rotor/stator position detecting elements comprising sensed elements mounted on the motor rotor for rotation therewith and sensing elements mounted in fixed position relative to the rotor and adjacent the path of movement of the sensed elements so as to maintain the same radial distance between the sensing elements and the sensed elements during incremental angular displacement of the axis of rotation of the shaft and motor rotor.