AUTOMATIC MONITORING OF TOOL STATUS

Automatic monitoring system and method for providing an instantaneous tool status indication for a stock removal cutter when cutting workpieces in accordance with a given machining operation for which a substantially new stock removal cutter of the same type has a reference average tool wear coefficient R.sub.0. The system includes a torque monitor (7) for measuring a main drive cutting torque M during the cutting of an ith successive workpiece. Coupled to the torque monitor (7), is an instantaneous tool wear coefficient processor (13) for calculating a plurality of instantaneous tool wear coefficients r.sub.(j) during the cutting of the ith successive workpiece. Coupled to the instantaneous tool wear coefficient processor (13) is an average tool wear coefficient processor (14) for calculating an average tool wear coefficient R.sub.(i) from the plurality of instantaneous tool wear coefficient r.sub.(j) And finally, coupled to the average tool wear coefficient processor (14) is a tool wear coefficient comparator (15) for comparing each average tool wear coefficient R.sub.(i) to the reference average tool wear coefficient R.sub.0 to provide an instantaneous tool status indication for the stock removal cutter for each ith successive workpiece.