A Force Transducer for a Turret Lathe

Summary

This paper considers the design, implementation and testing of a multi-component force transducer for a turret lathe. The system developed, using a dynamometer and strain gauges, permits measurement of the three components of cutting force in turning operations and of torque in drilling operations. The dynamometer has been designed as an integral part of the coupling between the turret and the machine, and to be capable of operating in a machine shop environment.

Results are presented of static tests which show that, after digital processing, the transducer signals are linear, non-interacting and represent the forces with an accuracy of approximately ±1. 5%. The dynamic performance is largely determined by the filtering which is necessary on the outputs of the strain gauge bridges. Results are given to show that sensible measurements during cutting are obtained with a response time of approximately 10 milliseconds. These tests also verify that the stiffness of the dynamometer is sufficiently high and no adverse effects are experienced even under very severe cutting conditions.