Linear position sensor feedback mechanism

An apparatus configured to measure the output of a rotary actuator unit includes a rotary actuator unit. The unit includes a stationary portion, a rotating portion, and a main rotational axis (L) that runs in an axial direction from a first end of the rotary actuator unit to a second end of the rotary actuator unit. The first end is opposite the second end. The apparatus also includes a linear position sensor comprising a follower, a sensor, and a sensor arm, wherein the follower is attached to the sensor by sensor arm; and wherein the sensor is attached to the stationary portion. The apparatus also includes a follower track attached or formed in, or on, to the rotating portion. The follower track is aligned in the circumferential direction that is perpendicular to axial direction of the main rotational axis (L). The follower is configured to follow the follower track.