There can be many reasons for the early failure of CNC turning and milling machine tools. The following are some possible reasons:

1. Design or manufacturing defects: If there are defects in the design or manufacturing process of the machine tool, it may lead to early failure. For example, factors such as unreasonable part design, improper material selection or poor workmanship may cause machine tool failure.
2. Service life of components: Each component of the machine tool has a certain service life, and wear, fatigue or failure may occur after a period of use. Early failure may be due to the premature expiration of the life of a critical component, such as bearings, gears, screws, etc.
3. Operation error: The operator is not familiar with the correct operation method of the machine tool, or uses wrong cutting parameters and working methods, which may cause the machine tool to malfunction in the early stage. For example, excessive cutting force, overloaded operation, improper cutting speed, etc. may cause damage to the machine tool.
4. Improper maintenance: Improper maintenance and maintenance may also cause early failure. If the machine tool is insufficiently lubricated, not cleaned thoroughly, or not inspected and maintained according to the specified cycle, the probability of failure will increase.
5. Environmental factors: Environmental factors such as poor construction environment, dust, moisture, vibration or high temperature may have a negative impact on the normal operation of the machine tool and cause early failure.
6. Electrical problems: Faults in the electrical system or unstable power supply may cause early machine failures, such as short circuits, loose cable connections, or power supply problems.
7. Problems with materials used: If there is a problem with the quality of the material of the processed workpiece, such as containing hard particles or inclusions, etc., it will cause additional wear and damage to the components of the tool and machine tool.

These are just some of the common reasons that can lead to early failure of CNC mill-turn machines. In order to reduce the risk of failure, it is recommended to carry out regular maintenance and maintenance of the machine tool, and ensure that the operators receive professional training to operate and use the machine tool correctly. In addition, choosing high-quality machine tools and accessories and ensuring good environmental conditions can also reduce the occurrence of early failures.