Want to understand CNC Machining? Read this!

Posted on Aug 7, 2020

Want to understand CNC Machining? Read this!

What is CNC Machining? You often see and hear the term CNC Machining whenever the topic is related to industrial and manufacturing applications. But what exactly defines CNC Machining and what should you know about it? Let’s break it down one by one.

CNC - Computerized Numerical Control

In the past, a machine tool needed to be controlled and supervised by an operator at all times during the machining process. Thanks to technological progress and since the addition of Computer Aided Design (CAD) and Computer Aided Machining (CAM) in the 1970s this became more and more unnecessary.

Computerized Numerical Control integrates a computerized device with the machine tool allowing for fully automatic operation. This automated machining process overcomes the limitations of manual control, requiring the operator to control and carry out the machining via levers, buttons, and wheels. This automation not only made the workspace safer for human operators but also increased accuracy and productivity.


CNC Machining Applications

CNC Machining can be used to perform a wide range of manufacturing operations including cutting, milling grinding, turning, sawing, hobbing, honing, and many more. It is also suitable for many different types of materials such as metals, plastics, wood, glass, foam, and composites, and finds application in a variety of industries, for example, the automotive industry, aerospace, medical, military parts, and others.

Usually, CNC Machining refers to subtractive manufacturing processes in contrast to additive manufacturing processes, such as 3D printing or injection molding operations. Subtractive processes remove material from the workpiece to create a finished part, while additive processes assemble layers of material to produce the desired form and formative processes deform and displace stock material into the desired shape.

Each type of manufacturing process has its advantages and disadvantages, that we will talk about in another article. Now, let’s take a closer look at the CNC machining process itself before we distinguish some of the most common CNC machining operations.

:: Read more : How to keep your CNC Machining Center in good shape


The CNC Machining Process

At the beginning of every CNC machining process, there is a 2D vector or 3D solid part CAD design. With Computer-aided design (CAD) software designers and manufacturers create a model of the finished part along with technical specifications, such as dimensions and geometries, that is necessary for the CNC machining process. Computer-aided manufacturing (CAM) software then extracts the part geometry from the CAD design file and generates the digital programming code which will control the CNC machine and the tools to produce a part identical to the original design.

The programming language behind CNC machining software is referred to as G-code and it controls the various movements and parameters of the machine, such as the speed, feed rate, and coordination. CNC machining makes it possible to pre-program the sequence of machine tool functions and run them in a cycle, all with little involvement of human operators. This CNC program acts as instructions for the CNC machine; it submits machine commands dictating the tooling’s actions and movements to the machine’s integrated computer, which operates and manipulates the machine tooling. Initiating the program prompts the CNC machine to begin the CNC machining process, and the program guides the machine throughout the process as it executes the necessary machine operations to produce a custom-designed part or product.


Types of CNC Machining Operations

As we have mentioned earlier CNC machining suitable for a wide variety of industries, including automotive, aerospace, medical industries, to produce a wide range of products. Let us first have a look at some of the most common CNC machining operations.


CNC Milling

CNC Milling is the most common CNC machining operation in the world of manufacturing today. It is a machining process that employs rotating multipoint cutting tools to remove material from the workpiece. Standard milling machines operate on three axes (X, Y, and Z), though more advanced mills can accommodate additional axes. Operational capabilities of the milling process include face milling—cutting shallow, flat surfaces and flat-bottomed cavities into the workpiece—and peripheral milling—cutting deep cavities, such as slots and threads, into the workpiece.


CNC Turning

CNC Turning is a CNC machining process that employs single-point cutting tools to remove material from the rotating workpiece. In lathe machines or turning centers, the workpiece is rotating and cut in a circular direction. This material removal process creates rotational parts by cutting away unwanted material. Thanks to CNC controls on modern CNC Lathes these machines can perform cutting operations with extremely high precision and at a very high speed. Without CNC lathes many complex and intricate parts that are manufactured today would be impossible with just a manual lathe. CNC machining capabilities of the turning process include boring, facing, grooving, and thread cutting.


CNC Drilling

CNC drilling is a CNC machining process that employs multi-point drill bits to produce cylindrical holes in the workpiece. CNC Drilling Machines operate by spinning a drill bit and cutting it into a block of material. The drilling operation on a CNC drilling machine is a cutting process. Using a unique drill bit, holes of a circular cross-section are cut into the workpiece. The most common are rotary cutting tools with multiple points. As the drill bit presses against the workpiece, it rotates at high speeds that range between hundreds and thousands of revolutions per minute (RPM). The outcome is precision-drilled holes that benefit many industries and for a multitude of applications.


CNC Grinding

CNC grinding uses a rotating grinding wheel to cut away material from a workpiece. Grinding machines are mostly used during the final stage of a manufacturing process, as they can achieve very high-quality surface finishes. Modern CNC grinding machines can reliably and process even very complex crankshafts, camshafts, valves, and other components in a very efficient and reliable manner. When it comes to CNC machining with grinders, we can distinguish surface grinders, cylindrical grinders, centerless grinders, internal grinders, and special purpose grinding machines.


Other CNC Machining Operations

Above are some of the most common CNC Machining operations but many more exist in the world of manufacturing. Other mechanical CNC machining operations include Sawing, Broaching, Honing, Lapping, and many more. On top of that, there are novel CNC machining operations such as cutting operations via electrical discharge (EDM Machines) and plasma (Plasma Cutting Machines).


CNC Machining on IMTS-Exhibition.com

CNC Machining is a too complex of a topic to comprehensively cover in just one article. We hope while reading this piece you have learned about the basics of CNC Machining. If you want to know more about CNC Machines and their applications make sure to check out our other blog entries. Also, check out our search function to find hundreds of CNC machines in our product database.

If you are interested in a more in-depth look at various manufacturing topics make sure to check out our MTS Industry Channel. In this show, we introduce new products and trends while visiting manufacturers in their facilities!

If you have any feedback regarding this article or other suggestions, please send us a message!

:: Read more : The History of CNC Machining Center: Why And How Is It Developed?


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