A flexible ball-end milling system model for cutting force and machining error prediction

This paper presents a flexible system model for the prediction of cutting forces and the resulting machining errors in the ball-end milling process. Unlike the previously developed rigid system model, the present model takes into account the instantaneous and regenerative feedback of cutting system deflections to establish the chip geometry in the cutting force calculation algorithm. The deflection-dependent chip geometry is identified by using an iterative procedure to balance the cutting forces and the associated cutting system deflections. A series of steady state 3D cross-feed ball-end milling cuts were performed to validate the capability of the present model in predicting the cutting forces and the resulting machining errors. It is shown that the flexible system model gives significantly better predictions of the cutting forces than the rigid system model. Good agreement between the predicted and measured machining errors is demonstrated for the simple surfaces generated by horizontal cuts.