Selection of cutting conditions for a stable milling of flexible parts with bull-nose end mills

In this paper, a three-dimensional dynamic model for the calculation of the stability lobes of low rigidity parts is applied for the prediction of chatter vibrations during the finish milling of aeronautical parts that include thin walls and thin floors. Hence, an accurate selection of both axial depth of cut and spindle speed can be done. The following methodology is applied: first, a modal analysis of the test device is performed; second, stability lobes are calculated; finally milling tests validate the approach. In the example included in this work, the lobes diagrams obtained for the thin floors are accurate, defining an approximate borderline of stability.