The reason that affects the accuracy of CNC processing

The effect of CNC processing position error on processing accuracy. Position error refers to the degree to which the actual surface, axis, or symmetrical face of the part being processed changes or deviates from each other relative to its ideal position, such as verticality, position, symmetry, etc. Position error in CNC machine tool processing usually refers to dead-zone error. The main reasons for the position error are the processing error caused by the gap and elastic deformation caused by the transmission during the machine part processing process, as well as the position error caused by the frictional force that the tool head needs to overcome during processing. In open-loop system, position accuracy is greatly affected, while in closed-loop follow-up system, position accuracy mainly depends on displacement detection.
The processing accuracy error caused by the geometric error of CNC machining. In the processing of CNC machine tools, due to external factors such as external forces, heat generated in processing, the geometric accuracy of the machine is affected, and the geometric deformation of parts machined on the machine will lead to geometric errors. According to the study, there are two main reasons for the geometric error of CNC machine tools: internal factors and external factors. The internal factors that cause the machine tool geometry error refer to the geometric error caused by the machine tool’s own factors, such as the horizontality of the machine tool bench, the horizontality and straightness of the machine guide, the geometric accuracy of the machine tool and fixture, etc. External factors mainly refer to the geometric errors caused by external environment and thermal deformation during processing. For example, geometric errors caused by the thermal expansion and deformation of tools or parts during cutting can affect the machining accuracy of machine tools and parts.
From the long-term data analysis and practical operation of parts processing, we can see the error of processing accuracy caused by the positioning of CNC machining machine tools. The positioning of the machine tool has a great influence on the processing accuracy of the CNC machine tool. Structurally, the processing error of CNC machine tools is mainly caused by positioning accuracy, and the machine tool injinding system is the main link affecting positioning accuracy. The incoming system of CNC machines usually consists of a mechanical drive system and an electrical control system. In structural design, positioning accuracy is related to mechanical transmission systems. In closed-loop systems, CNC machines can usually prevent positional deviations in major components of the inlet system, such as ball screws and other components, by positioning the detection device. However, for open-loop system, the processing accuracy of CNC machine tools is greatly affected because of the many factors and complex conditions, which can not be monitored.