Vibrations:

In a machine tool, two types of vibration might occur, for example self excited vibration and forced vibration. Such vibrations lead to enhanced wear of cutting tool, poor surface quality and disadjustment of the joints. Forced vibrations are caused because of periodic exciting forces, say, because of interrupted cutting. Self excited vibrations take place more often in metal cutting, and mainly it is because of the following two reasons:

(1) Alter in frictional force throughout cutting, and

(2) Instability of BUE resulting in the continuously altering cutting forces. Tool geometry and cutting conditions also influence vibration in the machine tool, which in the end influence the machined surface quality also [Arshinov and Alekseev, in the year 1975]. Flank wear of the tool and rigidity of the machine tool also influence vibrations. More rigid is the system, less is the vibration.