Rotary position encoder for rotatable shafts

A rotary position encoder, comprising:

• a hub that directly mounts on an end of a rotatable shaft of a machine tool and that rotates concurrently with the rotatable shaft, wherein the hub comprises a cup formed in a first end to receive the rotatable shaft and a plurality of equally spaced axial grooves formed on an inner surface of the cup creating portions of the cup that are thinner than other portions of the cup;
• a collar configured to collapse the cup around the end of the rotatable shaft;
• a sensor configured to detect a rotational position of the hub;
• a housing, wherein the sensor is mounted to the housing in a position adjacent to the hub;
• one and only one bearing, wherein the hub is rotatably coupled to the housing via the one and only one bearing;
• and
• a bracket comprising a central portion attached to the housing and a plurality of flexible mounting tabs extending away from the central portion for mounting the rotary position encoder to the machine tool at a plurality of corresponding anchor points, wherein the central portion of the bracket defines an opening through which the hub extends away from the housing.