The development of CNC machining programs can be roughly divided into two steps. Firstly, develop a process route for processing parts, and then determine the process size equipment, process equipment, cutting procedures, and labor quota for each process. The two are interrelated and should be comprehensively analyzed.

The overall layout of the process flow is to develop an overall plan for the process flow, with the main task of selecting various processing methods, determining the processing sequence and quantity of each aspect.

The general principles for developing a process route are as follows.

1. Prioritize the reference plane.

In the processing process, the workpiece should be used as the positioning reference first to ensure the processing quality of subsequent processes. It is called the antecedent benchmark.

2. Division of processing stages.

For surfaces with high machining quality requirements, they can generally be divided into three stages: rough machining, semi precision machining, and precision machining. In order to ensure processing quality and facilitate the rational use of equipment, the heat treatment process is arranged to easily detect billet defects.

3. Behind the front hole.

For parts such as the box, bracket, and connecting rod, the flat surface should be machined before machining the holes. Therefore, the plane positioning of hole energy not only ensures the accuracy of plane and hole positions, but also brings convenience to the processing of plane holes.

4. The grinding treatment of main surfaces (such as grinding, grinding, precision grinding, etc.) should be placed at the stage of the process route to avoid damage due to the smoothness of the processed surface.