Machining of free-form surfaces. Part II: Calibration and forces

In the machining simulations of 3D free-form surfaces by ball-end milling, calibration coefficients play very critical role in force predictions. In other words, obtaining the calibration coefficients from calibration tests is a very influential process in the prediction of cutting forces. Accurately obtained calibration coefficients lead to better force predictions. In the literature, the calibration coefficients are assumed to be independent of start and exit angles of the engagement region, thus they are assumed to be identical for any engagement region. Calibration coefficients are obtained from the horizontal slot cutting tests and these tests are repeated for different depth of cuts. In this paper, in order to achieve more accurate force predictions in free-form machining simulations, a new modification algorithm for calibration coefficients is presented. In this research, with theoretical analysis and experimental force signals, it is shown that the inclination angle has a great importance in calibration and in force simulation of 3D free-form machining.