Abstract
An analytical model is constructed to obtain stability lobes in end milling with irregular pitch cutters, and the reason why the regenerative effect is canceled by the irregularity is clarified. Furthermore, a simple method to optimize the pitch angles is proposed in the present research. It has been known that the regenerative chatter vibration is suppressed with the irregular pitch cutters, but the suppression mechanism has not been well understood. This mechanism is clarified here by assuming that the chatter vibration does not grow or damp in one rotation of the cutter, i. e. the process is understood by averaging the exciting chip load in one rotation. Based on this understanding of the suppression process, a new method is developed to obtain optimum pitch angles with which the regenerative effect can be cancelled out. The developed model and the proposed method are verified experimentally in the present report.
