What are the reasons for the chaotic vibration ripples on the cylindrical surface of the machined workpiece?

(1)主轴滚动轴承滚道磨损，间隙过大。

(2) The axial movement of the main shaft is too large.

(3) Chuck and connecting disc are loose, which makes workpiece clamping unstable.

(4) The sliding surface clearance of the chute is too large.