Abstract: A machine tool controller and part inspection monitor that controls part cutting by a machine tool (21) and provides a readout of cutter deviation beyond a preset tolerance is disclosed. Axis position sensors (23) continuously sense the position of the part (if the part is moved), the position of the cutter (if the cutter is moved) or the position of the part and the cutter (if both are moved) along various control axes. A data processor (31) uses the sensed axis position data to continuously determine the transfer function of the machine tool (21). The data processor (31) combines the transfer function information with data that defines the centerline of the cut to produce control signals suitable for controlling part and/or cutter movement. The location and amount of deviation from the defined centerline greater than the allowable tolerance are recorded and read out.