Analysis of tool deflection in micro milling of graphite electrodes

In this paper, the tool deflection is first analyzed analytically, based on a four-section cantilever beam representation of the tool. Contributions of different sections of the tool to total tool displacement are quantified. Then the influence of cutting parameters (width of cut, depth of cut, and feed per tooth) on tool deflection are investigated experimentally using precise laser-based measuring technique. Empirical modeling of tool deflection curves is based on a mixed full factorial (2(1)3(2)) design of experiments to find a functional interrelation between the tool deflection close to the tip and the cutting parameters. The results show that response surface model of tool deflection can be used to characterize the process behavior across a useful range of cutting conditions. Analytical and empirical model predictions are compared with experimental results and a good agreement is observed.