Tag Archive Reasons affecting CNC machining accuracy

Reasons affecting CNC machining accuracy

In the field of machining industry, what are the reasons for the influence of CNC machining accuracy? Let’s look at the following reasons:

  1. The first is the error of position influence: it usually refers to the change or deviation degree of the mutual position of the actual surface, axis or symmetrical surface of the machined part relative to its ideal position, such as perpendicularity, position, symmetry, etc.
  2. Machine tool error: the self error of the machine tool usually refers to the dead angle error. The main causes of position error are the machining error caused by the gap and elastic deformation caused by the transmission in the machining process of machine tool parts, and the position error caused by the friction force that the tool head needs to overcome in the machining process. In the open-loop system, the position accuracy is greatly affected, while in the closed-loop servo system, the position accuracy mainly depends on the displacement detection.
  3. Geometric error: machining accuracy error caused by geometric error of CNC machining. In the process of CNC machining, due to the influence of external factors such as external force and heat generated in machining, the geometric accuracy of machine tool is affected, and the geometric deformation of parts processed on machine tool will lead to geometric error. According to the research, there are two main reasons for the geometric error of NC machine tools: internal factors and external factors. The internal factors causing the geometric error of the machine tool refer to the geometric error caused by the factors of the machine tool itself, such as the levelness of the machine tool workbench, the levelness and straightness of the machine tool guide rail, the geometric accuracy of the machine tool and fixture, etc. External factors mainly refer to the geometric errors caused by the influence of external environment and thermal deformation in the machining process. For example, the geometric error caused by the thermal expansion and deformation of tools or parts in the cutting process will affect the machining accuracy of machine tools and parts.
  4. Cumulative error: from the long-term data analysis and actual operation of part processing, it can be seen that the machining accuracy error caused by the positioning of CNC machining machine tool. The positioning of machine tool has a great influence on the machining accuracy of NC machine tool. In terms of structure, the machining error of NC machine tool is mainly caused by positioning accuracy, and the feed system of machine tool is the main link affecting positioning accuracy. The feed system of NC machine tool is usually composed of mechanical transmission system and electrical control system. In the structural design, the positioning accuracy is related to the mechanical transmission system. In the closed-loop system, the CNC machine tool can usually prevent the position deviation of the main components in the feed system (such as ball screw and other components) through the positioning detection device. However, for the open-loop system, due to many influencing factors and complex conditions, it is impossible to carry out positioning monitoring, so the machining accuracy of NC machine tool is greatly affected.

The above explanation is the reason why Dongguan CNC machining accuracy is affected. I hope it will be helpful to you after reading it.

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