A MECHANISTIC MODEL TO PREDICT THE CUTTING FORCE SYSTEM FOR ARBITRARYDRILL POINT GEOMETRY

A mechanistic model is developed to predict the forces for arbitrary d rill point geometry. The cutting lips are divided into elements and th e elemental forces are determined from a fundamental oblique cutting m odel. A method is developed to parametrically define the cutting lip i n three-dimensional space and to determine the oblique cutting paramet ers (cutting angles and chip thickness) at each element on the cutting lip. The model does not require calibration experiments for each poin t geometry. The conical drill is used to determine the model coefficie nts for a tool and workpiece material combination and these are used f or other drill point geometry. Model simulations match experimental da ta very well for four commercial drill point geometry-the Racon, Helic al, Bickford and Double angle drill points.