Abstract: Key techniques in modeling and simulation of cutting forces in ball-end milling process with a flexible cutter are studied. First, the idea to extract the chip geometry for general 3-axis ball-end milling operations, in the form of in-cut segments of the engaged edges, using solid modeling technique, is proposed. Then, on the basis of the empirical relationship between cutting forces and chip load, a three-component force model is developed. The calculation formula of deflection-dependent instantaneous chip thickness under three-dimensional cutter feed motion is devised in two steps. First, the cutter deflection is calculated, by modeling the ball-end milling cutter as a solid cantilever beam rigidly supported by the tool holder. Then, the expression of chip thickness is established by analyzing the effect of cutter deflection on the cutting path of cutter teeth. Based on the modeling and simulation techniques introduced, a simulation system for prediction of cutting forces in 3-axis ball-end milling process is developed. The applicability of the system is demonstrated through a typical instance. The simulation results show a very satisfactory agreement with those obtained by the experiments.

Key words: Ball-end mills, Cutter deflection, Milling force, Modeling, Simulation