Today, CNC machines are a mainstay in the manufacturing process. They are intricate devices used to program machines to work on different materials based on the programmer’s command.
CNC machines have been in the market for a long time. However, if you’ve never used one or even heard of them, you might find it a daunting task to understand how it works.
If you plan to buy CNC machines for your company, you need to know what they are, why they were invented, how they work, and their history.
This blog will talk about a CNC machine, explain the history of CNC machines, enumerate the different types, and tell you how to use a CNC machine.
What is a CNC Machine?
CNC – which stands for Computer Numerical Control – is the process of using a computer and CAM (Computer Aided Manufacturing) program to control automated movements in machines, such as milling or lathing equipment that produces shapes from metal dies mounted on its surface by tool holders called tailstocks. In addition to producing physical products, this technology can also be used when making complex patterns off-site instead of having someone manually make them locally.
A CNC machine makes signs, wooden products, toys, or other products that don’t need to be very elaborately designed to look good. It is a computerized device capable of taking various materials and converting them into a finished product. They have been used in several industries, from aerospace to the automotive industry.
History of CNC Machines
The first public appearance of CNC machines can be traced back to the second half of the 20th century. In the 1940s and ’50s, CNC machines were based on perforated and punched tape.
At the time, the standard language of many of these machines, called G-Code, allowed computers and devices to talk to each other and communicate information such as the position of tools, X, Y, and Z axes, direction, spindle speed, and more.
Over the years, CNC technology became established because of manufacturers beginning to replace the old technology of manual processing with computers and numeric control. With advancements in computation and processing power, CNC processing was born.
In the 1960s and 1970s, as computer technology shifted to more reliable machines, businesses began to use CNC machines instead of the older NC systems. In the 1980s, the cost of microprocessors and CNC machines fell so low that small local networks (LANs) began to emerge, allowing a larger number of manufacturers to take advantage of this versatile process previously reserved for universities and astronomical companies to build computers.
In 1952, Richard Kegg manufactured the first CNC milling machine at MIT. William M. Pease and James O. McDonough designed an experimental control mill on behalf of Parsons Company of Michigan to receive directional data and punch paper tapes.
While the modern mainstay of manufacturing is computers, numerical control (CNC) dates back to the 1940s, when the first numerically controlled machines (NC) appeared. The IBM 602A Data Multiplier is considered the first CNC machine, a system that could read, produce and manufacture goods based on pre-programmed information. Until this day, the first true numerical control machine for producing goods (e.g., Helicopter blades, templates, and punch cards for feeding suitcases) is regarded as such a system and as the first system to read and produce parts from this information.
These machines changed the world of manufacturing for the better by enabling programmable designs that were previously not possible!
The history of numerical control or NC began with the automation of machine tools, which incorporated the concept of programmable logic, and today continues with the progressive development of CNC technology. The first conception of the idea of automatic control machines in this direction that reduced the need for a lot of human input and monitoring was developed by John T. Parsons, who created the idea for a numerical control NC machine with punching tape.
In 1949, the Air Force financed Parsons to bring to life the first draft of NC – machining by creating a machine with a motorized axis that would help produce helicopter blades programmable using the perforated tape method. While working at IBM, John T. Parsons studied the possibility of controlling a machine to make blades with a computer.
How Do CNCs Differ from NC Machines?
CNC machines differ from numerical control machines. They use digital code instead of manual punching tape. This means that they produce parts faster than previous machining techniques, and the digital CNC code allows programmers to correct their errors more efficiently.
CNC machining provides engineers and designers with high-precision parts to meet the requirements for products and machines that require increased efficiency.
Fast-Forward To Today
In contrast to 3D printing, CNC milling is a subtractive manufacturing procedure, where the parts are created by essentially removing material from a large block of metal or wood; the process is controlled by a computer.
A CNC machine combines several tools, including drilling, turning, and milling tools, to build a cell of CNC machines that can be selected to use the tools. Each tool is a self-contained machine tool in a CNC machine. The cutting movement of the spindle accelerates the tools in exchange for other operations performed as part of a program by a computer-controlled base machine. In CNC plastic processing machines, the function is determined by a program that controls tools and blocks within the machine.
CNC machining is a manufacturing process in which a computer-controlled machine uses programming code to manufacture a product. CNC automation offers significant flexibility in how parts are held during the production process since it takes little time to switch machines and produce different components. The CAD software enables accelerated production design, simple revision capabilities, and endless software revisions and updates, ensuring sustainable investment in manufacturing.
CNC machinery is equipped to make custom parts from the CAD files you provide for the design. Furthermore, automation and technical support make it possible to run many parts at once without milling, turning, or grinding.
How Do CNC Machines Work? An Overview of the CNC Machining Process
When CNC machines first originated in the late 20th century, they took their instructions from punch cards. We have come a long way since then.
In the modern-day, CNC machines are fitted with a powerful computer on board. Onboard-mounted computer CNC machines are typically best suited for industrial purposes.
For a micro-business, a small business, a small machine shop, a hobbyist, a solopreneur, or a freelancer, a CNC machine connected to and controlled by an external computer like a PC or laptop is ideal.
Regardless of the type of CNC machine used, it essentially works by the computer controlling a sequential arrangement of mechanical components like motors and drivers that keep the machine’s axes in a controlled and pre-programmed motion.
CNC machines regularly and consistently monitor and adjust the speed of the cutter to ensure a smooth and flawless finished product output.
1. The Flexibility of CNC Machines
If you are exploring CNC machines, you are likely to come across terms like “2.5 axes”, “3 axes,” and “5 axes”. These refer to the flexibility of the machine. The larger the number of axes, the more directions the CNC machine can work in.
The advantage of more degrees of freedom is that the CNC machine can manufacture a more complicated and greater variety of products.
The CNC machine is typically programmed by an engineer using Computer-Aided Design (CAD) or Computer-Aided Manufacturing (CAM) software.
This software helps the designers and programmers to make informed and accurate calculations of 2D and 3D paths of the CNC’s tools.
Then, the program (digital file) is transferred to a post-processor, where it is transformed into “G-code.”
Finally, the G-code is uploaded to the CNC machine.
G-code is the program or computer code that instructs the CNC machine on how and when to move the cutter and the stock material relative to each other.
The G-code also provides information to the machine on the usage of feed rate, spindle speed, type of cutting tool, the flow of the coolant, and more!
Depending on the CNC machine, the G-code, likewise if the cutting tool needs to be swapped.
What Are the Different Types of CNC Machines?
CNC machines come in a plethora of types, sizes, and variations. From large industrial milling machines to small desktop-sized cutting machines, there is one for all!
Here, we will look at eight types of CNC machines.
This uses basic drill bits wherein the drill bits spin at high speeds, and their relative motion with the stock material leads to a finished product.
The functioning of CNC lathes is opposite to that of drill machines.
Here, unlike drill machines, the stock material in a CNC lathe is spun at high speeds while the cutter or the drill bit remains stationary.
3. Milling Machines
A CNC mill is the most common type of CNC machine. Additionally, they are also the most precise. The milling machines use rotating cutting tools that eliminate material from the workpiece with precision and ease.
Want to know more about how much CNC mills cost and how to buy them? Check out this article.
4. CNC Routers
A CNC router is essentially a hand router that is mounted to and operated using a CNC machine.
It consists of a rotating tool called the endmill which carefully and precisely cuts away material from the stock.
The router operates along X, Y, and Z directions.
A CNC router mainly consists of:
- A gantry (controls the tool head’s X and Y axes)
- The tool head (has a motor that allows the spindle to move along the vertical axis)
- The spindle
5. CNC Welding Machines
A CNC welding machine, just like the router, is a welder mounted on a computer-operated machine.
The different types of CNC welding machines are:
- Spot welding
- Seam welding
- Tig welding
- Butt welding
- Wedge welding
- Friction welding
- Laser welding
Important factors to consider when choosing a CNC welding machine
- Material of the stock
- Type of joint to be welded
- Necessity of automation
- Support and documentation
- Ease of loading and using the materials
6. CNC Plasma Cutter
A CNC plasma cutter consists of a plasma torch that is moved and operated by a CNC machine.
Plasma cutting offers unparalleled precision and sophistication in cutting sheet metals, bolts, pipes, and more!
M-code or G-code files uploaded to the CNC machine determine the pathways and contours of the plasma cutter.
7. CNC Laser Cutter
As the name implies, a CNC laser cutter uses a laser to cut stock material (usually in the form of sheets).
The CNC laser cutting machine achieves this by concentrating a very high amount of heat on a small point and vaporizing it, thus effectively cutting the material.
8. CNC Waterjet Cutter
A CNC waterjet cutter employs water at very high pressures (1,000 to 6,000 bar) to cut through materials. To put this into perspective, the average atmospheric pressure is only 1 bar.
The principle employed here is abrasion. A high-speed water jet is very abrasive. As a result, it slices through even the toughest materials like rock, steel, and carbon fiber with little effort.
6 Benefits Of A CNC Machine
1. Can Manufacture Complex Designs
CNC machines, programmed with advanced design software such as Pro Desktop (r), allow users to manufacture products that could not be made on manual machines with qualified designers and engineers.
2. Very Precise
CNC machinery is an indispensable part of the manufacturing industry because they design complex shapes and constructions with 100% precision and efficiency.
The manufacturing industry relies heavily on computers for numerical control of CNC machining, including the operation and use of engineering equipment such as milling, molding, vertical milling, and lathes.
Since a computer operates a CNC machine, such machines eliminate the possibility of human error to a considerable extent and produce the desired shape of the product.
3. The Process is Automated
Unlike a manual lathe, a CNC milling machine is operated by converting a 3D CAD model into a set of computer instructions that dictate tooling operations and movements.
Automatic machining is a process that performs actions that maintain the reach and performance of a manually operated machine but with fewer errors and better speed.
Furthermore, unlike humans, CNC machines are great at repeatability. They can perform the same tasks and manufacture the same product hundreds of times without exhaustion, boredom, or error!
4. Improved Speed and Accuracy
Using a CNC machine instead of manual machining results in improved accuracy, higher production speed, increased safety, higher efficiency, and, above all, cost savings. CNC computers control the manufacturing and machining process with pre-programmed CAM software that dictates the movement of tools and machines.
Because CNC machines are in use 24 hours a day, 365 days a year, they only need to be switched on and off for occasional maintenance. They are programmed and engineered to be manufactured hundreds or thousands of times before making the same product.
5. Reduces Human Intervention Extensively
Although less human power is needed to operate a CNC machine than to operate a machine, CNC machines do not need qualified engineers for their skills and the waste of years of training and education.
Operators only need basic training to work on the machine, and no degree is required.
6. Quickly Detects Wear, Damage, And Defects
Sensors detect component wear and send signals to the operator that the machine needs to be serviced instead of waiting for it to fail.
Companies from defense, aerospace, medicine, marine, automotive, electrical industry, and many others demand will be immensely benefitted.
Whether you are a small business owner or a hobbyist and want to buy a manufacturing and prototyping machine, you can certainly find the one that suits your specific requirements. At CNC Masters, you can also explore CNC Machines for industrial use.
If you have any other questions or concerns about this topic or any other marketing or technology topic, please get in touch with us at CNC Masters.