The chatter marks produced by CNC vertical lathes are usually caused by vibration during the cutting process. This vibration can produce periodic marks or textures, affecting the surface quality and machining accuracy of the workpiece. The following are some common causes of vibration marks on CNC vertical lathes:

1. Tool problems: The selection, wear or damage of CNC vertical turning tools may cause vibration marks. For example, unstable tool installation, uneven tool tip wear, improper tool edge selection, etc. may cause vibration.

2. Clamping problem: If the clamping of the CNC vertical lathe workpiece is not firm or the fixture itself is defective, it will cause the CNC vertical lathe workpiece to vibrate during the processing and produce vibration marks.

3. Machine tool problems: The insufficient rigidity of the CNC vertical lathe itself or the unstable support structure of the machine tool may cause vibration problems. This may include issues such as the design of the CNC vertical lathe bed, wear of the guide rails, loosening of the ball screws, etc.

4. Improper cutting parameters: If the CNC vertical lathe cutting parameters are improperly set, such as unreasonable selection of feed speed, rotation speed, etc., the CNC vertical lathe may cause increased vibration during the cutting process.

5. Workpiece material: The processing of some special materials by CNC vertical lathe can easily cause vibration, such as cast iron, steel, etc., especially when quenching layers or brittle areas appear during CNC vertical lathe processing.

6. Resonance during the cutting process: When the natural frequency of the CNC vertical lathe cutting system matches the excitation frequency during the machining process, the CNC vertical lathe may cause resonance phenomena, resulting in increased vibration and vibration marks.

7. Cutting method: Inappropriate cutting method or tool path of CNC vertical lathe may cause uneven cutting force, thereby causing CNC vertical lathe vibration problem.

8. Coolant problem: Insufficient supply of CNC vertical lathe coolant or poor coolant quality may cause increased friction during the cutting process, thereby increasing vibration.

To solve the vibration mark problem of CNC vertical lathe, it is usually necessary to comprehensively consider the above factors and take corresponding measures, such as adjusting cutting parameters, optimizing tool selection, improving clamping methods, maintaining machine tool equipment, etc. Through reasonable adjustments and improvements, CNC vertical lathes can effectively reduce the occurrence of vibration marks and improve processing quality and accuracy.