Detection of tooth breakage in end milling using machine tool axis controlsignals

lThis paper considers the feasibility of utilizing existing machine tool ax is drive control signals as a mechanism for the early identification of too l breakages. In particular the paper outlines the utilization of axis tacho meter feedback signals as a means of monitoring the cutting process of a co mputer numerical control vertical milling machine. The work describes how a fault signature, corresponding to a tool breakage, can be identified in th e axis tachometer signals at varying feed rates. The results of the preliminary testing of a monitoring system utilizing exi sting axis feed drive signals are presented. The paper then outlines steps being taken to develop the application of the method to an increased range of cutting conditions. This work was based upon a study of the interrelatio nship between the axis control signals when cutting is proceeding in either the X- or the Y-axis direction, and when both the X axis and the Y axis ar e feeding simultaneously.