During Computer Numerical Control (CNC) machining, production devices and tools move according to computer software. The program can be used to operate a variety of complex machines, including milling machines, CNC milling machines, lathes, and grinders. Three-dimensional cuts can be made in one set of instructions using CNC machining. In this article, we will discuss some basics of CNC machines and provide comprehensive information about different types of CNC machines. If you are familiar with the CNC process and its operation, you will be able to better understand the difficulties associated with effectively using data for CNC machining or cutting. Remember that CNC machine tools used for metal processing, or other materials, differ from each other. We hope that the following article will help you better understand the machining process and explain the types of CNC machine tools, which will positively affect the improvement of production speed in your plant.
Types of CNC machines - characteristics
Currently, the most popular types of CNC machines are as follows:
- CNC milling machine
- CNC lathe
- CNC drilling machine
- CNC laser cutting machine
- CNC grinder
- CNC water jet cutting machine
- CNC plasma cutting machine
- CNC electrical discharge machine
- CNC Milling Machine
- 3D Printer
Milling Machine, types of CNC machines
Some of the most popular CNC machines are milling machines, which include integrated tools most commonly used for drilling and cutting. To position and move the spindle in various ways, the factory develops and converts special programs composed of letters and numbers (G-code). Every movement and action of the spindle and tool is guided and directed by computer code for precise cutting and transforming the workpiece into a planned custom component. Some typical tasks that a CNC milling machine can perform include threading, turning, drilling, face milling, and end milling. CNC milling machines are available in configurations from three to six axes. The three axes in the simplest 3-axis CNC represent movement in the X axis (horizontal), Y axis (vertical), and Z axis (depth). Compared to other CNC devices, such as CNC routers, CNC milling machines are relatively large and expensive. Some of the more well-known manufacturers of large CNC milling machines include Okuma, Haas, and DMG Mori.
Lathe, types of CNC machines
You can do many practical things with this CNC machine. They are generally shorter and more compact than CNC milling machines, as they have fewer axes. Its main part is a lathe, which controls the program and sends materials to the computer. It is currently often used due to its speed and precision. After initial setup, it can be easily operated by ordinary people.
Drill, types of CNC machines
Similar to traditional drills, CNC drills use rotating cutters to make holes in stationary objects. However, CNC drills are more precise and flexible than traditional drills, as they rely on CNC technology. For example, holes can be machined by CNC drills with tolerances as small as 0.001 mm. Moreover, they work on a wide range of materials, including wood, plastic, and metal. In addition, many CNC drills have a tool head that can accommodate multiple drills and allows for quick switching between them during production. Therefore, if hubs, gear wheel blanks, and machined shafts are to be produced, a CNC drill should be used.
Types of CNC Machines for Laser Cutting
CNC laser cutters are similar to CNC plasma cutters in terms of their ability to cut hard materials. But unlike plasma cutters, which use plasma, CNC laser cutters use a strong and highly focused laser light (ionized gas) to perform the task. CNC laser cutters generally provide greater precision and better surface quality than CNC plasma cutters, as the laser has fewer points of contact and spread than the torch. Moreover, CNC laser cutters are significantly more expensive than CNC plasma cutters with the same parameters (accuracy and cutting depth). However, CNC plasma cutters offer greater cutting power, as plasma is stronger than laser. They are most commonly used for cutting wood, metal, and plastics. The power of the laser can be adjusted depending on the density and hardness of the material, easily cutting through the material. The shape of the material is usually a sheet in a CNC laser cutter. The material is then precisely cut by the laser beam moving back and forth on it. To make a precise cut, the thermal action of the laser evaporates or melts the material. CNC laser cutters can often produce a range of patterns compared to other cutting devices. Often the resulting cuts and edges are so delicate and clean that polishing is no longer required. Therefore, CNC laser engraving machines are typically used for the production of parts and engraving machine parts. Laser engraving is widely used in decorative craft, including in signage, wood art, and glass engraving. When narrow tolerances and precise results are required, use CNC laser cutting.
CNC Grinder
This is a well-made tool that separates metal from metal using rotating wheels. Camshafts, ball bearings, drive shafts, and other functional parts that require precise finishing are often processed on CNC grinders. Cylindrical details are usually produced using CNC grinders. Grinders can also be used to produce other types of machined items.
CNC Water Jet Cutting Machine
As the name suggests, CNC water jet cutters use high-pressure water streams to cut materials. CNC water jet cutting is often the first choice when working with temperature-sensitive materials, such as plastics and aluminum, which can melt at high temperatures. Although these machines can cut with water alone, additional abrasive materials such as garnet or aluminum oxide are often added to the water to enhance cutting performance. CNC water jet cutters are more expensive than plasma cutters when comparing their specifications. However, it is cheaper than a CNC laser cutter with the same specifications. One of the drawbacks of CNC water cutters is that they operate slower than CNC plasma cutters and CNC laser cutters.
CNC Plasma Cutting Machine
Similar to laser cutters, CNC plasma cutters offer a high level of cutting precision and wide material compatibility. They differ from laser cutters only in that they use a plasma flame for cutting. Plasma torches produce high-energy plasma (or electrically charged gas) at temperatures up to 50,000 ° F. Anything that conducts current is effortlessly cut through by this immense heat.
CNC Electric Discharge Machine
It is also referred to as sparks. A unique type of CNC machine, it uses electrical discharges to process the material into the desired shape. The discharge can damage the material it is supplied with, as it has a temporary effect. CNC Electro-erosion machines use it to shape materials by creating controlled sparks. The material is placed on top and bottom of the electrodes, and the computer determines how many discharges the electrodes will generate.
CNC Milling Machine
A CNC router is primarily used for softer materials and is less precise. The cost of a CNC router is significantly lower than the cost of a CNC mill. You can buy a high-quality CNC mill for less than 800 PLN compared to a basic CNC mill, which costs over 45,000 zlotys. To process materials such as wood, steel, composites, aluminum, foam, and plastics into desired patterns and shapes, CNC routers use computer numerical control to determine the spindle path and machine path. The mechanical base, spindle, stepper controller, stepper motor, controller, and power supply are the basic elements of a CNC engraver. CNC plotters speed up production, reduce waste, improve accuracy, and increase productivity. Most CNC mills perform well in creating modest projects, handling basic and complex prototype projects in all three dimensions. CNC mills are available in various axes, from three to six.
3D Printer
This is a CNC machine that prints one project at a time. CAD and CAM processes are used to develop designs and drawings, which are then replicated using 3D printers. CNC machines are used in 3D printing and other constructions.
Advantages and Limitations of CNC Machining
Advantages:
CNC machines help manufacturers increase productivity and accuracy, and reduce the risk of human error, by enabling manufacturers to automate various production operations that would otherwise have to be done manually. Furthermore, it should be noted that:
- CNC machining is ideal for producing multiple parts
- Different materials can be processed on CNC machines
- CNC equipment produces items quickly
- CNC equipment is very precise
- CNC machining has various finishing options
Limitations:
The capabilities of a CNC machine can be limited by the complexity and age of its control and drive systems. Most CNC controllers only support circular and linear motion. On many machines, arcs are generally only allowed in the basic XYZ plane. The axis of rotation can be treated as linear motion, only in degrees, not in space. Two or more axes must interpolate (move together in precise synchronization) to produce arc or linear motion at an angle to the main axis. Rotary and linear axes can also be interpolated simultaneously. Five-axis machines require precise synchronization of all five axes, which is a difficult task. It is very important that the machine controller can quickly interpret incoming data, send commands to the drive system, and track the speed and position of the machine. Older and cheaper equipment is obviously less efficient in this respect, just like older computers perform demanding tasks more efficiently and faster than modern computers.
Application of CNC technology
Although we usually think of computers from the last two decades, CNC technology has been around since the 1940s. Since then, CNC has significantly evolved and currently has a wide range of new applications. Let's discuss some of the most important applications and advantages of CNC machining.
CNC machines are repeatable
The main advantage of CNC pressing is that once the project is defined, the material will be able to produce as many copies of the project as possible. After installing the application, you can save it and use it at any time, whether you are making a plaque, engraving a sign, decoration or a car part.
Dental Material
You may be surprised to learn how often dentists use CNC machines, especially when fitting dental crowns. Although wood and sheet metal are typically manufactured using CNC services, they are capable of producing much more. Even crowns and implants can be cut using CNC software, as the technology is so precise. The beauty of this procedure is that it is very simple to set up and can create a crown with great accuracy that fits exactly where it is intended in the mouth.
Military Equipment
You probably know the controversy around 3D printers due to their ability to produce guns without serial numbers. However, CNC machines have been around for a long time and have always had this potential. Additionally, CNC machines can even be used to modify rifles by adding grips and other accessories. The only difference compared to a 3D printer is the amount of material needed to start. Although the production of firearms without a license is prohibited, many different firearms manufacturing companies produce their products on CNC milling machines. Military and defense sectors often use CNC production to produce various types of weapons beyond firearms. A large part of the equipment throughout the industry comes from CNC production.
Construction
Even if it's not surprising, CNC milling is also very useful in construction. Even the most skilled carpenter may struggle to achieve the level of precision required for some jobs, especially when working with existing structures.
Transport
This is a broad concept, as the services provided by CNC technology in this field are very diverse. CNC technology is used in various ways by the aviation, rail, and automotive industries, as it provides such a wide range of services. To ensure the proper functioning of each part of an airplane at thousands of feet high, each part must be manufactured with high precision. Therefore, the industry has traditionally relied on machining services. To ensure safety, railway lines and cars also had to be properly constructed. Car manufacturers must make sure that quality control is their main goal, as over 70 million vehicles are produced each year. There must be uniformity everywhere. Therefore, since machines can provide more regularity than humans, CNC services are very useful in this industry.
Research and Development
Prototypes are essential for research and development work in almost every sector, along with a certain degree of trial and error. This includes physics, chemistry, biotechnology, carpentry, and other disciplines. Any concept that comes to your mind can be realized with masterful precision thanks to CNC machining. From the very beginning, almost every industry you can think of has used CNC to create accurate prototypes and continues to do so.
Niche Production
In reality, CNC machines can do almost anything that needs to be made from an appropriate amount of any material. What other machine can make a door, a pulley, an electric guitar, and a dental crown within a few hours? CNC technology has raised the production standard in all professional and fashionable sectors and day by day, computer control of numerical devices is getting better and better.