Today, different manufacturing companies need to quickly deliver high-quality products to their customers in a short period. Numerical Control (NC) and CNC (Computer Numerical Control) machines can fulfill this need in a short time while maintaining the complexity and accuracy of the parts being machined. The main difference between these two types of machining machines is one that most people don’t realize. NC is a standard control that stores data as the machine works. On the other hand, CNC systems are more advanced because they can do more and are more flexible. In addition, CNC systems can perform logical machining operations.
NC and CNC are two different types of CNC machines. Let’s understand what NC and CNC are and their advantages and disadvantages.
What Is Numerical Control (NC)?
A fixed logic function is used in the NC system to handle system tools or system processing. It lets you control the movement of the machine and does many other things by giving instructions in the form of digital sequences. The electronic control methods give these NC systems great functionality. However, because of the way the control logic is wired, you can’t change the way the NC machine works, which is why it’s called “hardwired”.
An NC machine gets its instructions from an external source such as magnetic tape or paper tape. It reads the data from the tape and processes it step by step. The data is stored in the control system’s “buffer memory” memory. When the system runs with a single block of instructions, the next block of data is read from the tape and stored in the memory of the machine’s control system.
The NC system has many advantages and disadvantages. Some of its major advantages and disadvantages are given below.
Advantages of NC System
- NC system helps in extending the working hours of the machine. It also helps in reducing non-productive time as it avoids unwanted system actions such as changing tools or moving workpieces.
- People use these NC systems to manufacture complex parts that are prone to errors. As a result, the parts manufactured are more accurate, have fewer scars, and require fewer inspections.
- NC systems help to automate tasks such as drilling and cutting that used to be done manually. Because of this, the time required to complete the work has been reduced.
- Less experienced people can easily use the NC system. All the processes of the NC system are automated so the only work that needs to be done is to keep an eye on the job.
- Labor costs are reduced when using this technology because it does not require human help like normal machines. Therefore, the management can reduce the labor cost.
Disadvantages of NC System
- The technology used in NC machines is very difficult. To recoup their costs, they are used frequently which causes a lot of wear and tear. Because of this, these machines require more maintenance than most machines.
- Because of their complex and difficult technology, they require a greater investment. Because of the higher purchase cost, management must make better use of this machine to cover the cost by producing more. In this way, the management can get the best return on investment.
- It requires people with advanced skills because it uses complex technology that is not available to the average worker. It takes more time and money to find, hire, and train these people because they are harder to find.
- To make changes to NC machines and find out what the problem is, it is necessary to understand how NC code works. Therefore, employees need to be trained in the code, which adds to the cost.
What Is Computer Numerical Control (CNC)?
CNC stands for “Computer Numerical Control”. It consists of a combination of computerized control and digital control. It has a microprocessor (computer) inside which consists of memory registers. The memory registers have many ways in which the logic functions can be changed. This means that the machine operator can change the software on the controller. For CNC machines this is very useful.
CNC machines store logical functions and programs in special computer chips. This is why they are called “softwired”.
There are various advantages and disadvantages of computer numerical control. Here are some of the main pros and cons of computer numerical control.
Advantages of CNC Systems
- A CNC system can run all the time. It is more adaptable and can produce parts of constant quality and accuracy.
- It can make very accurate and complex designs in the shortest possible time. The amount of scrap, idle time, power usage, and start-up time are reduced.
- The CNC system is capable of manufacturing items with the same level of accuracy. When a CNC machine works, it makes the same part. They increase both production and job safety.
- CNC machines can do the job more precisely and accurately than other machines that are operated manually.
- CNC machines do not require an experienced person to operate them. Semi-skilled users can also do the work more accurately and precisely.
Learn more about the benefits of CNC systems in 7 Top Benefits of CNC Machining.
Disadvantages of CNC Systems
- It requires the operator to know how to use a computer and write codes.
- CNC machines are more expensive than manually operated machines.
- CNC machines are more expensive to maintain.
- CNC machines are more temperature-demanding and need to be placed in an air-conditioned area.
- Parts for CNC machines are expensive.
Main Differences between NC and CNC
NC and CNC are different in many important ways. Here are some of the major differences between NC and CNC:
1. To tell the machine what to do, NC machines use perforated cards. CNC, on the other hand, uses a computer to run the machine.
2. NC machines require more time and skilled labor to make the product. On the other hand, CNC machines require less labor, are faster, and are more automated.
3. The operation settings of NC systems cannot be changed. CNC systems, on the other hand, can change their operation.
4. NC machines are cheaper, while CNC machines cost more and require more maintenance.
5. NC machines are less accurate and less flexible than CNC machines. In contrast, CNC machines process parts with greater precision and flexibility.
6. NC machines take more time to complete a job. In contrast, CNC machining takes less time to complete the job.
7. The information on the piercing card is the only way to change the NC program. CNC programs, on the other hand, can be changed directly through the computer system.
8. NC systems do not have memory to store instructions. CNC systems require memory to store instructions.
9. NC machines cannot run all the time. CNC machines can run 24 hours a day.
In addition to the differences between NC and CNC, we have prepared an article on CNC Machine vs 3D Printer.
Face-to-Face Comparison of NC and CNC
The next section will show you how NC and CNC compare with each other. These are the main differences between NC and CNC:
| Features | NC | CNC |
| Full Forms | NC is an abbreviation for Numerical Control. | CNC is an abbreviation for Computer Numerical Control. |
| Definition | It is described as a machine that follows a set of instructions in the form of letters, numbers, and symbols. This set of instructions is called a program. | It is described as a machine that controls the workpiece and moves cutting tools through the use of preset computer programs. CNC machine tools are programmed using letters and data. |
| Flexibility | It is less flexible than CNC. It is more flexible. | Cost It is less expensive than CNC. It is more expensive than NC. |
| Cost | It is less expensive than CNC. | It is more expensive than NC. |
| Input Mechanism | It utilizes punch tapes and punch cards for input. | It utilizes the keyboard for input. |
| Accuracy | It is moderately accurate. | It is highly accurate. |
| Operators | It needed highly skilled operators. | It needed less skilled operators. |
| Maintenance Cost | It requires less maintenance than CNC. | It required high maintenance than NC. |
| Memory | There is no memory in the NC for storing instructions. | It requires memory to store instructions. |
| Alteration in operation parameters | Alteration in operation parameters is not possible in NC machines. | Alteration in operation parameters may be possibly changed in CNC machines. |
| Modification in the machine parameters | It is done by modifying the data in the punch cards. | It may be done by using a computer system. |
| Execution time | It needs extra time to execute a task. | It needs less time to execute a task. |
| Service | NC machines may not run continuously. | CNC machines may run continuously for 24 hours of a day. |
Summary
The main difference between an NC machine and a CNC machine is that an NC machine uses a punch card to directly control the machine to machine the part. CNC machines, on the other hand, use a computer to talk to several MCUs (Machine Control Units) that are the source of the data.
FAQ
What Does “NC” Stand for in CNC Machining?
In the computer world, NC stands for Numerical Control. It refers to a machine that follows a series of instructions written in a program as a collection of numbers, letters, and symbols.
On the other hand, computer numerical control uses a computer program consisting of letters and numbers to control the movement of workpieces and tools. The program includes detailed instructions that explain how to manufacture the product and what mechanical steps need to be taken.
What Are the Different Types of NC and CNC Systems Used in Manufacturing?
Different types of NC and CNC systems are used in manufacturing. These include automatic tool changer CNC, grinding CNC, electrical discharge CNC, laser cutting CNC, plasma cutting CNC, milling CNC, 5-axis CNC, and routing CNC.
What Are the Advantages of CNC over NC?
When considering adding a CNC machine to your production process, it is important to consider the following:
- Not much knowledge or skill is required. Operators do not need to have a lot of specialized knowledge to run a CNC machine well.
- Simplified product customization. CNC machining technology makes it easy to replicate products on a large scale, thus providing mass production opportunities for more people.
- Reduce manual labor. CNC machines typically require less manual labor and are therefore more efficient.
- More production options. Using CNC software increases the number of products that can be produced, thus allowing for greater production flexibility.
What Is the Difference between CNC, NC, and DNC Systems?
- Machine programming in an NC system is accomplished with perforated cards and tape readers.
- CNC stands for “Computer Numerical Control”. It uses computer-based code writing and machine controller units to make the code understandable to the machine.
- Whereas DNC stands for Distributed Numerical Control, where many CNC machines are connected to a host computer via a network.