Flexure-based torque and thrust force drilling dynamometer with Hall effect sensor displacement measurement

This paper describes the design and testing for a low-cost, table-mounted drilling torque and thrust force dynamometer. A flexure-based (constrained-motion) design is detailed, where the rotation for torque and translation for thrust force are measured using a dual magnet-Hall effect sensor configuration that provides a linear voltage output. Two sensors are implemented for each direction to reject undesired structural dynamics. Validation experiments for torque and thrust force are reported using a commercially available, spindle-mounted rotating dynamometer. Results are provided for blind hole drilling in aluminum and stainless steel samples using two drill diameters and various feed rates.