Abstract: A self-centering device for a motor having a base and a shaft extending through the base and rotatable relative to the base along an axis includes a housing having a flange for securing the housing to the motor base. A bushing is connected to the housing and has a passage for receiving the motor shaft. A rotary encoder is secured to the housing and configured to measure at least one of position or rotation of the motor shaft. Positioning the motor shaft in the passage in the bushing centers the housing on the motor shaft to place the encoder in a desired position for measuring the at least one of position or rotation of the motor shaft.