An eccentric shaft becomes an eccentric when a circle does not rotate around its center. The eccentric shaft is also a kind of cam. Generally speaking, the main purpose of the eccentric wheel is to generate vibration. Like the electric screen, the vibrator in the mobile phone uses the eccentric wheel. Most of the eccentric wheels are round wheels, because the round wheels are easy to manufacture and the process is simple.

For turning eccentric shaft, measures shall be taken mainly in clamping to align the axis of the eccentric part to be processed to coincide with the axis of the lathe spindle.

Generally, the four jaw chuck is used for clamping eccentric workpieces with small quantity and low precision. When turning the eccentric workpiece on the four jaw chuck, first draw a line on the workpiece. It is to draw an eccentric circle and ensure the horizontal and vertical cross lines. So as to determine its position in the four jaw chuck according to these line