There may be many reasons why CNC vertical lathes vibrate, some of the main reasons include:

1. Tool instability or wear: Instability or wear of CNC vertical lathe tools is one of the common causes of vibration. If the tool installation is unstable or the tool is severely worn, it will cause instability and vibration during cutting.

2. The workpiece is too large or too heavy: When the workpiece processed by CNC vertical lathe is too large or too heavy, the machine tool may not be able to fully support the weight of the workpiece, resulting in vibration.

3. Improper clamping: If the CNC vertical lathe workpiece is clamped improperly, the clamping force is uneven or insufficient, it will cause the workpiece to move or vibrate during the processing.

4. Improper setting of cutting parameters: Improper setting of cutting parameters such as CNC vertical lathe cutting speed, feed speed and cutting depth can also cause vibration. If the cutting parameters are chosen too high or too low, vibration problems may occur.

5. Structural problems of machine tools: Structural problems of the CNC vertical lathe itself, such as wear or looseness of guide rails, spindle bearings and other components, may cause vibration.

6. Coolant problem: If the flow, pressure or temperature of the CNC vertical lathe coolant is unstable, it will also affect the cutting process and cause vibration.

7. Programming errors: CNC vertical lathe programming errors or unreasonable processing path design may also cause vibration. If the machining path is not smooth or there are too many sharp turns, the occurrence of vibration will increase.

Methods to solve the vibration problem of CNC vertical lathes include adjusting cutting parameters, replacing tools, improving clamping methods, maintaining machine tool structures, optimizing coolant systems, and improving processing procedures. By comprehensively analyzing the possible causes of vibration and gradually eliminating these problems, CNC vertical lathes can effectively reduce vibration and improve processing quality and efficiency.