An optomechanical photonic switch that exploits the stationary property of the minimum deviation angle of a dispersive prism is described. The switch is based on an optical beam deflector consisting of an electric motor with hollow shaft. The tip of the motor is fitted with a dispersive prism and the deflected beam is focused onto pixels arranged around a circular scan track. It is shown that the proposed switch is, for all practical purposes, completely insensitive to mechanical wobble of the motor. Furthermore, the existing technology suggests that such a small-inertia motor with no external load may achieve speeds up to hundreds of thousands of revolutions per minute and beyond. We suggest one application of the switch as a write gate of a time slot interchanger in the time-division switching of pulse code modulation (PCM) codes. It is shown that the proposed switch can achieve speeds up to and exceeding hundreds of megabits per second.