Study of the Tuning of Variable Pitch Milling Cutters

It is well known that variable pitch cutters may improve stability of a given milling operation. Several methods are known for tuning the consecutive pitch angles to approach idealistic phase shift on regeneration. Most of the tuning procedures are based on the measurement of the chatter frequency. However, these design procedures completely disregard the effect of the harmonics of the milling process. In this study, the efficiency of these methods is verified in milling for an interrupted cutting engagement. The critical analysis of different tuning methodologies are carried out by means of accurate stability charts constructed with semi-discretization. It is shown that the effectiveness of tuning can be improved further with numerical optimization techniques