Modeling of forces for drills with chip-breaking grooves

In this paper, a mechanistic modeling approach to predicting cutting forces for conical twist drills with chip-breaking grooves has been developed. The model is based on force principles for restricted contact cutting extended to take into account the presence of a groove on the drill rake face. The applicability of the model for arbitrary groove geometries has been ensured by eliminating the use of grooved drills in the calibration process. Four different combinations of groove geometries have been used for validating the model using high speed steel drills and low carbon steel workpiece material. The force predictions from the model were found to be in good agreement with the measured forces. The model was then employed to determine groove orientation and design parameters that minimize cutting forces, subject to the condition that chip breaking is satisfactory.