In-process monitoring of end milling cutter runout

An on-line methodology for the monitoring of end milling cutter runout is presented. Runout has been a limiting factor for achievable productivity in machining due to its adverse effect on tool life and part quality. However, calibration and adjustment of cutter runout have been difficult in that runout characteristics react dynamically to the actual machining process. The approach discussed utilizes the time-dependent spectral analysis of cutting force to estimate the cutter runout characteristics of magnitude and angular orientation. The presence of cutter runout generates a cutting force component at the spindle rotational frequency. Given a priori knowledge of the part's material properties, tool geometry, cutting parameters, and machining configuration, the instantaneous runout characteristics are recursively updated from their previous values and the recent measurement of cutting force. The recursive nature of this approach facilitates the in-process implementation of runout monitoring and provides opportunities for control and optimization. The analytical basis of the method is introduced, system mechatronics elaborated, implementation procedure presented, and resulting machining data examined. (C) 1997 Elsevier Science Ltd.