A generation of more efficient CNC tool paths using simulation modelling

Abstract

This paper presents two-phase optimisation strategy for efficient planning of finishing endmilling operations when machining pocket-type features. The optimisation mechanism controls dimensional tolerances through knowledge of cutting forces and the associated cutting tool deflections. The developed model of the end milling process describes the main parameters, such as chip thickness, engagement angles, cutting forces, cutting tool deviation, and simulates the relationship between them during the cutting operation. The created strategy is feed-forward and it is focused on cutting process geometry identification and specifics of machining pocket type features. The model-based simulation covers the general case of end-milling when the chip thickness is variable along the tool path. The developed off-line optimisation methodology creates more efficient milling process with variable feed rate, compared to the same tool path cut with constant feed rate derived from the worst-case condition. Up- and down-milling were modelled and optimised, and the predicted data was evaluated experimentally.