Analysis of drill dynamometer with octagonal ring type transducers for monitoring of cutting forces in drilling and allied process

In this paper, the analysis of octagonal ring type transducer has been carried out by considering some basic elastic theory of thin circular ring. Using those transducers, a drilling dynamometer was designed and constructed to measure drill cutting forces: thrust and torque. In the dynamometer, strain gages mounting places were indicated clearly on the transducers by appreciating characteristics of the strains due to drill forces. The wiring diagrams of the strain gages of dynamometer were illustrated separately for the forces to be measured. The rigidity of the dynamometer was also analysed considerably in detail by determining natural frequencies in vertical and torsional modes to avoid resonance. After having completed the construction of it, the dynamometer was tested by performing drilling and measuring the forces, thrust and torque, on SAE 1020 steel. The results were compared to similar works to show the performance of the constructed dynamometer. Complete construction drawings of the dynamometer were also presented to researchers of metal cutting.