CNC CNC machining process division of two principles

Precision CNC machining programming refers to the process of automatically generating CNC machining programs with the support of a computer and corresponding computer software systems. It gives full play to the computer's rapid calculation and storage functions.

1. The principle of CNC precision machining rough before fine

The processing sequence of each surface is carried out in the order of roughing, semi-finishing, finishing and finishing, with the purpose of gradually improving the accuracy and surface quality of the processed surface of the part. If the entire surface of the part is processed by CNC, the process arrangement is generally carried out in the order of roughing, semi-finishing, and finishing, that is, semi-finishing and finishing are performed after all roughing is completed.

During rough machining, most of the machining allowance can be quickly removed, and then CNC precision machining can be carried out for each surface in turn, which can improve production efficiency and ensure the machining accuracy and surface roughness of the parts. This method is suitable for machined surfaces that require high position accuracy. This is not absolute. For example, for some machined surfaces that require high dimensional accuracy, considering the rigidity, deformation and dimensional accuracy of the parts, these CNC precision machined surfaces can be completed in the order of rough machining, semi-finishing, and finishing. 

For machining surfaces with high precision requirements, it is best to leave the parts for a period of time between roughing and finishing processes, so that the surface stress of the parts after roughing can be completely released, and the degree of stress and deformation on the surface of the parts can be reduced, which is beneficial to improve the machining accuracy of the parts.

2. The principle of face before hole for precision CNC machining

For box, bracket, machine body and other parts, the plane outline size is larger, and the plane positioning is more stable and reliable, so the plane should be processed first, and then the hole should be processed.

In this way, not only the subsequent precision CNC machining has a stable and reliable plane as the positioning reference surface, but also the machining of holes on a flat surface makes the machining easier, and it is also beneficial to improve the machining accuracy of the holes.

Generally, the process can be divided according to the processing position of the part. Generally, the simple geometric shapes are processed by CNC first, and then the complex geometric shapes; the parts with lower precision are processed by CNC first, and then the parts with higher precision; the plane is processed first, and then the hole.