A process-design approach to error compensation in the end milling of pockets

Abstract

In the end milling of pockets, the tool deflection varies over the entire machining cycle, which includes straight segments as well as corners. The accuracy in corner cutting is strongly influenced by the deflection of the end mill caused by the variation of the cutting forces. The way to improve accuracy in corner cutting is by decreasing the radial depths of cut to reduce the cutting forces and thereby the end mill deflection errors. By process design it is possible to achieve gradual reduction in the radial widths of the cut during corner cutting. Thus, there is a need to identify the cutting conditions in order to control the process such that tool deflection errors are minimized and compensated for. The paper presents a process design methodology to achieve a significant reduction in the cutting forces and consequently in the tool deflection errors. The experimental results of cutting force measurement and the estimation of tool deflection errors are discussed in detail. The results indicate that significant improvement in the accuracy of end milled pockets can be obtained by error compensation.