CHIP LOAD KINEMATICS IN MILLING WITH RADIAL CUTTER RUNOUT

This paper presents the analytical modeling of chip load and chip volu me distribution in milling processes in the presence of cutter runout. The understanding of chip load kinematics has a strong bearing on the prediction of milling forces, on the assessment of resulting surface finish and tool vibration, and on the identification of runout for mul ti-toothed machining process monitoring and control. In this study a c hip thickness expression is analytically established in terms of the n umber of flutes, the cutter offset location and the ratio of offset ma gnitude to feed per tooth. The effects of runout geometry, feed rate, and depths of cut on the overall chip generating action is discussed t hrough the illustration of cutting regions and chip load maps. Explici t solutions for the entry and exit angles are formulated in the contex t of milling parameters and configuration. Experimental measurement of the resulting chip volumes from machining with an offset cutter is co mpared to an analytical model formulated from the chip thickness expre ssion. Additionally an average chip thickness prediction, based on the chip volume model in combination with the entry/exit angle solutions, is compared to data reported in the literature for validity assessmen t.