Tool orientation effects on the geometry of 5-axis ball-end milling

5-axis ball-end milling has found application in various industries especially for machining of parts with complex surfaces. Additional two degree of freedoms, namely, lead and tilt angles make it possible to machine complex parts by providing extra flexibility in cutting tool orientation. However, they also complicate the geometry of the process. Knowledge of the process geometry is important for understanding of 5-axis ball-end milling operations. Although there are considerable amount of work done in 3-axis milling, the literature on 5-axis ball-end milling is limited. Some of the terminology used in 3-axis milling is not directly applicable to 5-axis ball end-milling. Hence some new process parameters and coordinate systems are defined to represent a 5-axis ball end-milling process completely. The engagement zone between the cutting tool and the workpiece is more involved due to the effects of lead and tilt angles. In this paper, effects of these angles on the process geometry are explained by presenting CAD models and analytical calculations.