No matter how any part is machined, its part drawing must be analyzed first. Fully understand the geometry, size, material and heat treatment of the parts to be processed, and prepare for the process treatment.

2. Process analysis and treatment:

Process analysis is to compile the processing technology of parts, including blank selection, fixture selection, tool selection and heat treatment arrangement. For NC machining, there are also the selection of the origin of workpiece coordinates, the determination of tool changing points in machining and the determination of tool path.

A. Determine the machining scheme: firstly, select the CNC turret bed and fixture to be used, and then select the machining tools and cutting parameters.

B. Establish the workpiece coordinate system: determine the correct relationship between the workpiece coordinate system and the machine tool coordinate system, so as to prepare for the determination of tool path and the calculation of geometric dimensions during machining, and at the same time, consider the form and position tolerance requirements of parts.

C. Determine the tool setting point and tool changing point during machining: The tool setting point and tool changing point of CNC machine tools are generally the same as the starting point of the tool during machining. In the selection of this point, firstly, the tool path should be detected and calculated, secondly, the tool changing point should have a safe distance from the workpiece, but it is not allowed to collide with the workpiece when changing the tool, and finally, it should be noted that the distance between the tool changing point and the workpiece should not be too large, resulting in too large idle stroke, so as to keep a safe and reasonable distance between the tool and the workpiece. Pay attention to the different NC machine tools, the determination of the cutter point and the cutter change point is different.

D. Choose a reasonable tool path: the tool path is the specific movement path of the tool relative to the workpiece during the whole machining process, including the fast idle stroke and the machining process as required. When selecting, we should first ensure the accuracy and surface quality requirements of the machined parts, secondly, we should pay attention to reducing the feed route and idle stroke as much as possible to improve production efficiency, and finally, we should pay attention to simplifying the calculation and reducing the number of programs and programming workload.

E. Reasonable arrangement of auxiliary functions: During the processing, some auxiliary items should be arranged reasonably as needed. Such as: the start and stop of cutting fluid, the speed change of spindle, and the arrangement of stopping detection of important machining dimensions.

3. Mathematical processing:

The so-called mathematical processing is to calculate the data needed for NC programming according to the drawing size of the part and the determined tool path. It mainly includes the calculation of base points, the fitting of list curves and the coordinate operation of complex three-dimensional curves or surfaces.

4. Prepare parts processing procedures:

According to the determined tool path, the calculated data and the determined cutting parameters, and according to the machining instruction code and program segment format of the numerical control system, the part machining program list is compiled. The writing process should strictly abide by the provisions of the programming instructions, and the programming methods generally include manual programming and computer-aided programming. Single small parts can be programmed by hand, and complex large parts can be programmed by computer, which improves the efficiency and quality of programming and reduces the labor intensity of programming.

5. Debugging and finalization of processing program:

After the machining program is completed, it should be input into the computer of numerical control system software. You can input it through the CNC control menu, or you can use the editor in DOS. After input, grammar, teaching demonstration, simulation of machining and other tests should be conducted. Finally, after the first piece is checked correctly, the final processing procedure is determined.