A mechanistic model to predict the cutting force system for arbitrary drill point geometry

A mechanistic model is developed to predict the forces for arbitrary drill point geometry. The cutting lips are divided into elements and the elemental forces are determined from a fundamental oblique cutting model. A method is developed to parametrically define the cutting lip in three-dimensional space and to determine the oblique cutting parameters (cutting angles and chip thickness) at each element on the cutting lip. The model does not require calibration experiments for each point geometry. The conical drill is used to determine the model coefficients for a tool and workpiece material combination and these are used for other drill point geometry. Model simulations match experimental data very well for four commercial drill point geometry-the Racon, Helical, Bickford and Double angle drill points.