What is Computer Numerical Control (CNC)?

Modern manufacturing machines offer exceptional precision. Their fast speed allows them to complete complex projects quickly. CNC is the technology behind those machines, enabling them to achieve precision. But what is Computer Numerical Control (CNC), and what makes it superior? 

 

I know that CNC technology is widespread, but people don’t understand how it works. In the previous article, we looked at various CNC machines. However, this article is going to be different. We will only focus on the CNC technology that makes machines stand out. So, let’s get started!

 

Overview of Computer Numerical Control (CNC)

CNC stands for Computer Numerical Control. It is a technology that uses some codes to run different machines. Those codes are based on the 3D models or pre-made designs. Computers use those codes to run machine tools. Due to the involvement of computerized systems, the machines do their job precisely.

 

First, the CNC is not a machine—take this myth out of your mind. It is a technology that can be used with different machines. This technology aims to enhance the precision and speed of machines. In the past, machines were inaccurate and slow, and achieving 100% precision was nearly impossible.

 

The reason was that old machines needed human involvement. As you know, humans were always prone to errors, which led to machines being less precise. However, CNC technology has eliminated the need for human efforts to be infused with machines. In simple words, it has automated the way manufacturing machines work.

 

CNC machines operate using programmed codes. They follow those instructions and act accordingly. This technology is not new; CNC machining has a history of several decades. However, using CNC in any machine makes it expensive. But that expense is worth it. Why? Because CNC enhances machine performance and precision.

 

Components of CNC System

 

The CNC system is not a single unit. Instead, it consists of different components that work in harmony. Each of those components performs a unique function. If any CNC component fails, the CNC system will collapse. Here is the list of those parts:

 

• Input Devices
• CNC software
• Feedback System (Sensors)
• CNC Control Unit (Controller)

 

Input devices are used to feed programmed instructions (codes) to the computer. Keep in mind that CNC works with codes. I’ll explain these coded instructions in the next part. The CNC software allows the creation of models/designs and coded instructions. Codes are different for different kinds of tasks.

 

The CNC control unit is of utmost value. It won’t be wrong to say that this component is the heart of the CNC system. It understands and interprets the coded instructions. After interpreting the code, the unit sends specific instructions to the tools. Every CNC system comes with a feedback system that ensures accuracy.

 

Once coded instructions are interpreted, does the machine tool follow them correctly? The CNC system uses the feedback system to determine this. This system consists of sensors that provide real-time information to the control unit. If there is a deviation, the control unit acts quickly to correct the error. All these components make CNC very precise and accurate. 

 

Types of CNC Program Codes

 

As I said above, CNC technology works by using programmed codes. There are two types of codes. Here are the names:

 

• M-codes
• G-codes

 

Both of these programmed codes are very important. G codes are associated with movement to cutting tools in CNC machines. Their purpose is to define the operation of the cutting tools. Simply put, they are responsible for the tasks that CNC machines perform. 

 

On the other hand, the M-codes perform the auxiliary functions. They have nothing to do with how the tools will act. Instead, their function includes switching on the coolant and changing the tools. They also control the starting and stopping of the spindle. Let me give you an example of M-codes:

 

• M05 codes give directions to turn off the spindle 
• M00 codes indicate the switching off of the machine
• M08 codes define the switching on of the coolant system for the machine

 

Similarly, many other numerical M-codes perform different functions. Both M-codes and G-codes use numerical numbers. Each number provides specific information to the control unit. G01 and G02 indicate the clockwise and anticlockwise movement of tools. These are G-code instructions that go to the computer.

 

How Does Computer Numerical Control (CNC) Work?

 

CNC technology is commonly used in machines where precision matters. Understanding how this CNC makes an impact matters the most. In the section below, I’ll explain the working and operation of the CNC system in machines. The section will use simple steps to help you understand properly.

 

1- Formation of Designs

 

The first step when using CNC machines is designing the required parts. For example, you have a metal piece and want to make it a specific shape. You’ll have to design the necessary shape of the part you need from the machine. Different software is available for creating these designs, and CAD is the most popular software.

 

CAD allows you to make a 3D design model. Remember, making this design is not easy. Small mistakes in design will result in wrong output. If you don’t have the required expertise, I recommend hiring a dedicated designer. Generally, manufacturers have in-house designers who use CAD and make 3D models. 

 

2- Creation of Coded Instructions 

 

The second step is to make the coded instructions. The computerized system doesn’t accept your design in the first step. Instead, the CNC control system can only read the codes. As I said earlier, there are two types of codes. So, you’ll have to cover your design using coded instructions.

 

Can you do it yourself? The answer is YES! CAM (Computer-aided manufacturing) software helps convert the design into code. This software understands and analyzes your given 3D models. After interpreting, it creates coded instructions for the specific shape or design. Computerized systems take these codes like instructions.

 

3- Feeding & Execution of Codes

 

CNC machines consist of input devices. These devices help feed the programmed instructions to the computer. The control unit of the CNC system interprets these codes and understands the instructions. After that, the control unit sends a message to the machines to follow specific instructions.

 

The machine consists of tools for cutting or shaping. These tools follow the instructions of the control unit. Remember, the control unit defines how tools will move after analyzing the code. So, the tool moves as per the instructions. The tools perform the associated actions. For example, the cutting tools cut the material.

 

On the flip side, grinding tools grind the material. Remember, this CNC technology can be used with different machines. For example, milling, lathe, and grinding machines use this technology. So, the tool performs the specific task to create the precise output. The control unit of the CNC system plays an integral role in executing codes.

 

4- Role of Feedback System

 

As I said above, the CNC system consists of many components. If any one component deviates from the instruction, the machine will give the wrong output. In such cases, the feedback system comes in handy. The CNC machines consist of sensors that monitor the working of the whole CNC system. If any part malfunctions, sensors detect the issue.

 

So, they send a message to the control unit about the error. As a result, the control unit rectifies that error that affects the machine’s precision. This feedback system is crucial. Remember, CNC machines generally don’t make errors. If there is any issue, the machine will act accordingly to give perfect output.

 

Advantages of CNC Technology

In the above section, I discuss how CNC systems work in different machines. Remember that CNC machines are costly. But you will see people saying CNC technology is worth the higher price. Have you ever wondered WHY? Let’s go down and discuss why CNC technology is so demanding.

 

1- Precision

 

The CNC system uses programmed instructions. The control unit ensures the machine’s tool follows those instructions. In this way, tools cut and shape the material with precision. There is no human effort involved. The CNC system is automated, which ensures you get what you feed. There is no chance of inaccuracies.

 

2- Speed

 

In the past, manufacturing machines were very slow. Humans had to work manually to run those machines. However, CNC technology has improved their efficiency. All you need is design and coded instructions. The computerized system will take the instructions and complete the job. You work to manufacture as many parts as you want.

 

3- Complex Parts

 

CNC technology can help make complex shapes. In the past, making complex parts was very tedious and required a level of expertise. But CNC technology helps make intricate shapes with ease. Making simple or complex shapes of material takes the same time. All you need is a 3D model or design. The CNC machines will do the rest.

 

4- Error Compensation

 

In the above section, I mentioned the feedback system. Sensors monitor the workings of these CNC machines. If there is an error, the sensor sends a message to the control unit. As a result, the controller immediately acts to overcome the error. So, you will get 100% precision as CNC technology compensates for the errors.

 

5- Versatility & Quality

 

The CNC technology makes machines very versatile. They can make any type of shape and work with any material size. For example, CNC machines can make aircraft parts. At the same time, they can also manufacture small parts such as nuts and screws. This makes them super efficient in the long run. 

 

It is no secret that CNC technology has been a great invention. It has uplifted the precision of manufacturing processes. Many modern machines use this technology. Many people believe that CNC is a specific device. That’s not true as this CNC is a complete system. It consists of many parts and components.

 

Conclusion

 

It is no secret that CNC technology has been a great invention. It has uplifted the precision of manufacturing and various surface roughness processes. Many modern machines use this technology. Many people believe that CNC is a specific device. That’s not true as this CNC is a complete system. It consists of many parts and components.

 

This CNC system works with different machines to enhance their precision. For example, a CNC milling machine helps you cut the material precisely. CNC grinding machines are excellent for grinding any object. This technology has very diverse uses. There is no limit to where it should be used. I hope this guide helps you know more about CNC.