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CNC machining refers to a process method that uses digital devices and information to control the movement of parts and cutters to process the parts on a CNC machine. It is an effective way to solve the variable rapid prototyping components, small batch parts, complex shape parts and high CNC precision machining components and achieve high efficiency parts.
What is CNC machining ？
CNC machining is a machining method that uses digital devices and information to control the displacement of parts and tools to process parts on CNC machines. It is an effective way to solve variable rapid prototyping components, small batch parts, complex shape parts, and high CNC precision machining parts and achieve high efficiency parts.
CNC machining is an efficient automatic machine tool composed of mechanical equipment and numerical control system, which is used to process workpieces with complex shapes.
Rapid prototyping CNC machining can continuously complete drilling, boring. Various processes such as milling, reaming and tapping greatly reduce additional processing time such as workpiece clamping time, measurement and machine tool adjustment. The parts with more complex shapes, high precision requirements and frequent replacement have good economic effects.
How does CNC machining work?
1. Design and Programming
Use computer-aided design (CAD) software to create a three-dimensional model of the workpiece, including the geometry and dimensions of the part.
The CAD model is imported into computer-aided manufacturing (CAM) software, and the CAM software generates numerical control codes (G codes) that contain machining parameters such as tool paths, cutting depths, and feed speeds.
2. Machine Preparation
The workpiece is fixed on the worktable of the CNC machine and the required tools, such as milling cutters, turning tools, or drills, are installed.
The operator calibrates the machine tool to determine the reference point (zero point) of the workpiece so that it is aligned with the coordinate system in the NC program.
3. Perform processing
The NC program is transmitted to the machine tool through the machine tool controller, and the controller controls the movement of the machine tool according to the program instructions.
The CNC machine tool processes the workpiece according to the preset tool path, removing material layer by layer through operations such as cutting, milling, and drilling to form the final part shape.
Based on the test results, if necessary, subsequent processing or correction is carried out to achieve the expected accuracy standard.
Different Types of CNC Machines
The earliest CNC machines date back to the 1940s, when electric motors were first used to control the movement of existing tools. As technology advanced, the mechanisms were enhanced with analog computers and eventually digital computers, giving rise to CNC machining.
The vast majority of today’s CNC equipment is fully electronic. Some of the more common CNC processes include ultrasonic welding, drilling, and laser cutting. The most common machines used in CNC systems include:
1.CNC Milling Machines
2.Lathes
3.Plasma Cutters
4.Electrical Discharge Machining Machines
Electrical Discharge Machining (EDM), also known as Die Machining and Spark Machining, is a process that uses electrical sparks to shape a workpiece into a specific shape. During the EDM process, an electric current discharge occurs between two electrodes, which removes certain parts of the workpiece.
When the space between the electrodes becomes smaller, the electric field becomes stronger and therefore stronger than the dielectric. This allows the current to pass between the two electrodes. Therefore, each electrode removes a part of the workpiece. Subtypes of EDM include:
Wire EDM: Wire EDM uses spark etching to remove parts of electronically conductive materials.
Sinking EDM: Sinking EDM uses electrodes and workpieces immersed in a dielectric fluid to form the workpiece.
During the flushing process, the debris from each finished workpiece is carried away by the liquid dielectric, which appears after the current between the two electrodes stops in order to eliminate any further charge.
5.Waterjet Cutting Machines
In CNC machining, a waterjet is a tool that uses high-pressure water to cut hard materials such as granite and metal. In some cases, the water is mixed with sand or other powerful abrasive substances. Companies often use this process to shape factory machine parts.
Waterjet can be used as a cooling alternative for materials that cannot withstand the high heat of other CNC equipment. Due to the cooling properties of waterjet, several industries such as aerospace and mining rely on waterjet for engraving and cutting, etc. Companies also use waterjet cutters for applications that require very intricate cuts in materials, as the lack of heat prevents any changes that metal-on-metal cutting may cause to the inherent properties of the material.
History of CNC machining
Before the introduction of Computer Numerical Control (CNC), the manufacturing process involved intense human labor, unnecessarily long production runs, wasted material, and was fraught with pitfalls. Today technology has dramatically improved the manufacturing process.
The introduction of CNC machining technologies offers a high level of reliability, making iterative processes more automatic. But what is CNC machining? What products can be made using CNC technology? How Does CNC Machining Work and What Materials Can Be Used in Manufacturing Processes That Use CNC Machines?
CNC machining technology was born from the needs of the aviation industry. In the late 1940s, an American helicopter company proposed it.
The original idea of CNC machine tools, the Massachusetts Institute of Technology developed a three-axis CNC milling machine in 1952.
This type of CNC milling machine was used for processing aircraft parts in the mid-1950s. In the 1960s, CNC machining prototypes and programming work became more and more mature and perfect.
Prototype CNC machining services have been used in various industrial sectors, but the aerospace industry has always been the most extensive CNC machine tool.
Some large aircraft factories are equipped with hundreds of CNC machine tools, of which cutting machines are the main ones.
CNC machined parts include integral wall panels, beams, skins, bulkheads, propellers, aircraft engine housings, shafts, discs, blades and unique combustion chamber cavity surfaces liquid rocket engine. The initial stage of the development of CNC precision machining is based on continuous path CNC machine tools, continuous path control.
Conclusion
CNC machining, or Computer Numerical Control, is a technology that uses computer programming to control machine tools to automatically perform precision cutting, milling and other operations. It is widely used in the manufacturing industry. By precisely controlling the tool path, it can achieve high-precision processing of materials such as metals and plastics. It is suitable for producing parts with complex shapes and strict dimensional requirements.
