The Characteristics and Steps of CNC Machining

The CNC machining process abides by the laws of machining cutting, due to its automatic process that applies computer control technology to mechnical processing, it has the features such as high processing efficiency and precision.

The CNC machining process includes the selection of tools, the determination of cutting parameters, and the design of cutting routes, it is the core of CNC programming. Only with reasonable technology can high-efficiency and high-quality programs be compiled. The critreia for measuring the quality of CNC programs is having the best effect with least machining time and tool loss.

The CNC programming refers to the whole process from part drawing to obtaining CNC machining program. Its main task is to calculate the the cutter location point (CL ponint for short) in the machining process.The cutter location point is generally taken as the intersection of the cutter axis and cutter surface, and the cutter axis vector is also given in multi-axis machining.

The CNC machine tool must input the command codes representing various functions into the CNC device in the form of a program, and the CNC device performs arithmetic processing, and then sends out pulse signals to control the operation of each moving part of the CNC machine tool, thereby completing the cutting of the parts.

There are currently two standards for CNC programs: ISO of the International Organization for Standardization and EIA of the Electronic Industries Association of America. And we use ISO.

With the advancement of technology, 3D numerical control programming generally rarely uses manual programming, but CAD/CAM software.

Steps：

1. Analyze the part drawing to understand the general situation of workpiece (geometry, workpiece material, process requirments, etc.).
2. Determine the CNC machining process of the parts (the content of the machining, the route of the machining).
3. Perform necessary numerical calculations (coordinate calculation of base point and node).
4. Write the program list (varies from tool to tool, follow the manual).
5. Program verfication (input the program into the machine tool, and perform graphic simulation to verify the correctness of the programming).
6. Process the workpiece (good process control can save time and improve processing quality).
7. Workpiece acceptance and quality error abaysis (inspect the workpiece, find out the cause of the error and the corrective method through quality analysis).