Abstract: A multi-frequency phenomenon in the process of chattering building up or dieing cut is observed by the chattering test with varying width of cut in this paper. It is very interesting that the frequencies are arranged at intervals of n/60(Hz) where n is the spindle speed. This phenomenon is caused by the frequency sifting mechanism in second with the geomenric constrained condition of phase shift between two consecutive cutting operation in certain length. Based on the mechanism, a new chatter monitor strategy has been proposed. i. e. within a certain frequency band to monitor some frequency intervals with n/60(Hz), and detection should be much more effective under operation.

Key words: Frequency sifting, Machine tool regenerative chatter, Monitor, Multi-frequency phenomenon