What is CNC machining process? Explain Types and Features!

What is CNC Machining Process?

CNC machine plays an important role in the world of modern manufacturing. The Computer Numerical Control can be called a CNC Machine and it tells the tool what speed and movement to follow while creating the desired part. We can create parts and components which are usually impossible to create manually. Also removes material from the base stock piece through milling, turning, or drilling other types of operations to create angles, shapes, and the finished product. CNC machining is the process in which we produce apart from solid material with the help of a computer-driven machine tool in different shapes and sizes. To get a desired shape from the workpiece, the CNC machine moves the cutting tools on multiple axes and the computer reads the program and interprets the design. The automated CNC cutting process is accurate and faster than the older manual cutting process where the movement of workpieces as well as tools is done with levers and gears. CNC machines can hold multiple tools at a time and can make many types of cuts as required. The machine access automatically the types of tools during the machining process to determine the complex workpiece a CNC machine can make.

How Does CNC Machining Work?

CAM is a software package that runs the software programs at CNC machines. It creates Numerical Control (NC) codes. The codes create paths and CNC machines follow the path. The CAM programming requires knowledge and skills to operate and run by a digitalized computer. It automates, monitors, and controls the movement of an industrial CNC machine. It is important to understand the NC codes for easy operation and some simple programs can be used by inexperienced users to run the CNC machines. Sometimes code generators assume mechanisms are flawless, despite there is the possibility of errors within the numerical control system. CNC machine programs can be fed to computers via small keyboards and aims to cut in more than one direction simultaneously. The code is written and edited by programmers and those programs are inputted via punch cards and retained in a computer’s memory. CNC systems have a more expansive computational capacity and newer prompts can be added to pre-existing programs through revised code.

What Material Can Be Used for CNC Machining?

Material selection is a key aspect of any manufacturing process. When it comes to selecting materials for CNC machining it is easy to mistakenly choose a material that’s sufficient for the project but not the best suited. There are various factors that should be considered when picking a material including workability, price, corrosion resistance, strength, weight, etc. Take a look at the most common ones to consider.

ALUMINUM

Aluminum alloys have a good strength-to-weight ratio and are easy to machine in large volumes. They have high thermal as well as electrical conductivity and are naturally resistant to corrosion. Aluminum 6061 is often used in CNC machining, and it is an all-purpose alloy. Aluminum 7075 is a step up from 6061 and is highly machinable. Aluminum alloys are mostly used in automotive parts, sporting goods, bike parts also in recreational items. Aluminum alloys are Ideal for aerospace frames and high-performance recreational equipment, it’s the strongest commercially available alloy.

STAINLESS STEEL

Stainless steel alloys are strong and resistant to distortion, wear, and corrosion, also they have improved machinability. Stainless steel alloy makes excellent nuts, bolts, non-marine grade fittings, shafts, and gears but they cannot be cold-formed, heat-treated, or welded, and special care must be taken with speed and the sharpness of cutting tools during CNC manufacturing. Stainless steel alloys can be welded and well-suited for a wide range of kitchen accessories, consumer and industrial applications, tanks, etc. It is non-magnetic, readily machinable, and corrosion-resistant. Stainless steel is strong, weldable, and one of the few marine-grades, and corrosion-resistant to the addition of molybdenum.

CARBON STEEL

Carbon steel is stronger and tougher. Carbon steel is often used as it is less expensive than most stainless steel and can be machined easily. This material is ideal for nuts, bolts, gears, shafts, connecting rods and it is weldable and can be hardened or heat-treated to achieve harnesses.

TITANIUM

Titanium is known for its high strength, toughness, corrosion, and resistance poor conductor of electricity. It is more expensive and often employed to manufacture parts for the most demanding aerospace, military, industrial applications. Titanium material is biocompatible and used in the manufacturing of medical devices.

NYLON

Nylon is a low-friction thermoplastic used as an alternative to metal in CNC-manufactured parts. It is chemical-resistant, impact-resistant, stiff, elastic, and strong and responds well to additives and fillers.

The Different Types of CNC Machines

CNC Milling Machine

CNC milling machine is the most common type of CNC machine that utilizes computer controls to cut various materials. The mills can translate specific programs of numbers and letters in order to move the spindle in various ways. A CNC mill is very large and costly and comes in three to six-axis configurations that can control the process operation through the XYZ three-axis. Also, it can be easily divided into vertical milling machines or horizontal milling machines and has a wide array of functions, such as face milling, shoulder milling, drilling and turning, tapping. Traditional milling machine, rotation speed can be adjusted to fix the bed base, and the bed can be moved by three axes, left and right, front and rear. The spindle of the CNC Mill is equipped with a tool holder. We can replace milling tools of different shapes and sizes and the fixed axis rotates. The workpiece can move to fix the bed base. CNC Mill Machine calculates the programming by G code can control the process operation only through the calculation. The machines are usually divided into vertical milling machines or horizontal machines.

CNC Lathe

CNC Lathe and CNC mills have the same controls can we can operate with both proprietary programming languages as well as G-code and can make precise cuts quickly by using various tools. The lathe machine lathe is a rotary workpiece and the cutter is the main working machine. The parts which formed are round tubes, rods, car screw patterns, car bar, pipe, rods with some drill arm chucks. finished products are, internal and external teeth, screw, shaft, tube kit, ring. Traditional lathe processes were not easy to handle whereas CNC lathe has overcome with improved efficiency and precision. Traditional lathes, large CNC lathes are common tool machines, high-speed lathes, hexagonal lathes, multi-axis lathes, and other special-purpose lathes.

Electric Discharge CNC Machines

Electric discharge machining (EDM) utilizes electrical releases which include a particular shape inside a specific material. Anodes are isolated and regularly get an electric voltage by a dielectric liquid from a workpiece by a progression of repeating electrical.

CNC Plasma Cutters

A CNC plasma cutter is a machine that can cut CNC routers through a wide range of different materials, including brass, aluminum, steel. The CNC plasma cutter and CNC routers are similar in size and can be used for a selection of industries like auto repair and restoration shops, fabrication and welding shops, industrial construction sites, salvage operation sites. With a plasma torch, they fly above the table and don’t require as much of a powerful setup.

Different Features of CNC Machining

1. Flexible and Versatile

CNC milling machines are suitable for the processing of multiple types of workpieces with different structures and shapes, and complete drilling, boring, reaming, milling planes, milling bevels, milling grooves, milling surfaces (cams), tapping, etc.

2. High Machining Accuracy

CNC milling machines have high machining accuracy under normal circumstances. CNC machine avoids the size of the same batch of processed parts and operating errors. They have a good dimensional identity, which greatly improves product quality.

3. High Production Efficiency

CNC milling machines are continuously variable and have the functions of milling machines, boring machines, and drilling machines. The process has fast forward, fast rewind, and fast positioning functions which reduce the workpiece clamping error. improves the production efficiency and the process is highly concentrated.

4. It Can Process Complex Shapes

CNC machine tools can mill plain curve contours and spatial surface contours. They have multiple feed coordinates.

5. Reduce the Labour Intensity of The Operator

The CNC milling machine observes the operation of the machine tool which completes the processing of parts to operating loading-unloading tools, keyboard, and workpieces, intermediate measurements.