This invention is related to a rigid tapping feedback assembly that is adapted to being retrofit on a milling machine having a spindle with a spindle end extending beyond a bearing cap and an automated drive. In embodiments, the assembly comprising a housing, spindle-pulley adapter that is drivably engaged with the spindle end, pulley assembly, shaft assembly, housing cover plate, and rotary encoder. The housing mounts to the bearing cap and holds the shaft assembly in substantially parallel-spaced alignment with the spindle-pulley adapter. The pulley assembly mechanically links the spindle-pulley adapter and the shaft assembly, typically utilizing pulleys and a timing belt. The housing cover plate mounts to the housing enclosing the assembly components above and supporting the rotary encoder in substantial axial alignment with the shaft assembly. In operation, the rotary encoder senses spindle rotational speed spindle and provides feedback to the automated drive to control downward movement of the spindle.