Automatic tool touch and breakage detection in turning

The Machine Tool Monitor (MTM) described in this paper is a tool breakage detection and a tool and part probing system for use on lathes. It uses a single accelerometer, mounted on the turret structure, as the sensing element. The system processes the sensor signals, and is programmed to recognize signal patterns resulting from the breakage of the tool, and the touch of the tool to the rotating workpiece or to a vibrating reference post. The system is integrated with the lathe's NC control to allow automatic reaction to the sensed events.