A chisel edge model for arbitrary drill point geometry

An oblique cutting model is developed to predict the thrust and torque created by the chisel edge of a drill with an arbitrary point geometry. The chisel edge geometry is modeled using a mathematical representation of the flank grinding parameters and the flute geometry. The varying cutting angles at the chisel edge are determined and used to calculate the force contribution of each element using a mechanistic modeling approach. The model is validated for three commercial point geometries - the conical, helical and Racon® drill points. Model simulations match experimental data well for the geometries tested and show a marked improvement over the orthogonal cutting model.