MODEL FOR CUTTING FORCES PREDICTION IN BALL-END MILLING

This paper presents the development and verification of a predictive model for the force system in ball-end milling. The force model is essentially derived from metal cutting theory and for the geometric relations of the ball-end milling process. A concise method for characterizing the complex geometry of a ball-end mill is first determined. This method of generation not only simplifies the description of the geometry of the cutting edge, but also provides the basis for the determination of all geometric parameters to an accuracy commensurate with that needed for the oblique cutting process. The force model developed is able to deal with many of the process variables, including changes in the axial and radial depths of cut and in the feedrate, as well as the eccentricity (runout) inevitably found in practice. As a result, the predicted cutting forces show a fairly good agreement with the values from the verification experiments.