What is cnc ? Due to the increasing complexity of product design, modern product manufacturing requires processes and techniques that ensure precision and accuracy. As a result, there is a rush to develop and innovate in manufacturing techniques, particularly the introduction of automation.
Through automation, CNC machining is a common manufacturing process known for precision, accuracy and complex product design capability. This article discusses the basics of CNC machining, its process, application and benefits.
In computer numerical control (CNC), a machine tool is controlled by a microcomputer attached to the tool. This microcomputer responds to a programming language called G and M codes, which contain instructions for machining parameters such as feedrate, spindle speed, cutting tool and coolant flow.
The microcomputer then transmits the instructions to the machine tool. As a result, CNC machining does not require manual operation, making it suitable for producing error-free parts regardless of the complexity of the product design.
CNC machining is a subtractive manufacturing process that uses instructions from a CAD model to create a product. The CNC machine machines parts of the part by turning, drilling or milling, in accordance with the code (g and m code) obtained from the CAD model.
CNC machining is compatible with many metals, plastics, wood and composites. It is a mainstream process for producing parts, alongside additive and formative manufacturing processes such as 3D printing and injection moulding. However, CNC machining has some advantages over these methods, such as high tolerance. Let’s read on.
This involves creating a 2D or 3D model design of the product. There is a wide range of software available for this process, the most popular being AutoCAD and SolidWorks. It is also possible to convert 2D designs into 3D designs, depending on the product requirements.
While many product designs may be straightforward, the creation of CAD models for complex product designs may require advanced skills.
The CAD model should be properly designed, showing the operator critical features such as tolerances, construction lines, threads and other parameters for effective machining.
CNC machines don’t understand the CAD model. In order for the machine to interpret the CAD model, you must convert it to a CNC compatible format. You can use CAM software such as AutoCAD, Fusion 360 or other online software services for this step.
This software converts to a CNC compatible format and instructs the CNC machine. Parameters associated with the machining operation, such as rotary and linear motion, cutting sequence, tool path, workpiece, machine speed, etc.
This involves selecting the right type of CNC machine and configuring certain operations before machining begins. The choice of machine depends on the workpiece, the complexity of the product design and the cost. The workpiece is then mounted on the machine.
The operator attaches the necessary cutting tools and starts the process. The process is automated. It continues until the computer program deems it complete. Machinists perform several levels of quality assurance checks during and after the machining process.
3D printing is an additive manufacturing process in which a material is melted, deposited and solidified using instructions from a CAD or 3D digital model. Like CNC machining, it is automated. However, unlike CNC machining, it is more suitable for a simple design.
Injection moulding is a plastics manufacturing process in which material is melted, injected into a prepared mould and allowed to solidify. It works by the same mechanism as other manufacturing processes such as blow moulding, overmoulding and insert moulding. It is an important part of the mass production of products.
Die casting is similar to injection moulding. However, it is suitable for metals such as aluminium. It involves melting the metal and injecting it into a prepared mould. The injection process can be low or high depending on the quality of the product.
