Abstract
In ball end milling, the cutting velocity of the sphere portion of the end mills changes in magnitude and direction at any point on the cutting edge, furthermore undeformed chip thickness also changes along the cutting edge. The chip is produced with various shear angles, chip flow angles and chip flow velocities so the cutting process is very complicated. In this report, a cutting model taking account of the condition of side-curl of the chip proposed in previous paper is presented. The cutting forces in upward or downward milling in which both cutting edges of the sphere and cylindrical portions engage with the workpiece are predicted by using the cutting model and energy method. The quantitative agreement between predicted and measured results is well enough.
