What Is Computer Numerical Control (CNC)? Meaning, Working, and Applications
Computer numerical control (CNC) is a computer-guided manufacturing and automating tool to shape materials with high precision and efficiency.
In traditional manufacturing, skilled operators manually guide tools to create parts or products. This work can be dangerous, especially when working with heavy machinery, dangerous chemicals, and harsh raw materials. Workers also experience fatigue and exhaustion due to repeated lifting, pushing, and pulling of the machinery. Computer numerical control (CNC) technology eliminates the need for constant human intervention, increases production speed, and reduces errors caused by human fatigue.
In this article:
What Is Computer Numerical Control (CNC)?
Computer numerical control (CNC) is a technology that uses computers to control machines in manufacturing processes. With CNC, computers accurately guide the movements of tools and machinery. The machine follows instructions like a person might follow a recipe. These instructions, written in G-code, designate how the machine should move its tools, what speed to operate, and where to make cuts.
To use a CNC milling machine, a worker loads the design on a computer. The machine reads the design and follows the instructions to carve out the desired shape from a block of material. The machine acts as a super-precise robot arm to repeatedly create intricate and complex shapes. CNC machines are incredibly accurate. They can make cuts at measurements smaller than the width of a human hair. This accuracy is measured in units like micrometers (µm) or thousandths of an inch (mil). This level of precision is crucial for industries that demand precise components, like aerospace and medical devices.
Some systems operate in a closed loop, which uses sensors to monitor the machining processes continuously. Corrections are made in real time when the tool deviates from the expected position. This feature improves overall quality and ensures consistency during mass production.
In addition to being used in factories for production, CNC enables rapid prototyping and customization. Engineers can easily modify instructions for different designs without changing the machine’s physical setup. Low-effort updates simplify experimentation and allow designers and engineers to adapt products based on changing customer needs.
Many industries use CNC machining, including aerospace, automotive, and electronics. Hobbyists in metalworking, woodworking, and 3D printing may also use CNC machining.
History of CNC Operations
In the late 1940s and early 1950s, engineers began to explore ways to automate machine tool operations. The first steps involved using punched paper tapes to control machine movements. This marked the transition from manual to semi-automated processes. However, the true breakthrough came in the late 1950s when John T. Parsons and his team at the Massachusetts Institute of Technology (MIT) developed a way to control machine tools directly using digital data. This innovation laid the foundation for modern CNC technology, which revolutionized manufacturing.
The 1960s witnessed the commercialization of CNC machines. Early CNC systems were large and expensive, primarily used in aerospace and automotive industries for their precision and efficiency. By the 1970s, advancements in microprocessors and computer technology led to more compact and affordable CNC machines, making them accessible to a broader range of industries.
The 1980s marked a pivotal point as CAD (computer-aided design) and CAM (computer-aided manufacturing) software began integrating with CNC systems. This allowed designers to create digital models and directly convert them into CNC instructions, streamlining the design-to-production process.
The 1990s and early 2000s brought further enhancements, including improved programming languages and multi-axis capabilities. CNC machines became capable of complex operations such as milling, turning, drilling, and more, guided by intricate G-code instructions.
CNC operations are now ubiquitous in manufacturing. The technology has advanced to include features like real-time monitoring, adaptive machining, and even artificial intelligence-assisted optimization.
In essence, the history of CNC operations showcases a trajectory of ingenuity and progress. It has evolved from rudimentary automation to an integral part of modern manufacturing, shaping industries and enabling the efficient and consistent creation of intricate and precise products.
How Does CNC Work?
In CNC systems, a programmer first uses CAD software to digitally design a part or product. Subsequently, the software generates detailed blueprints, including intricate dimensions and shapes. Meanwhile, CNC machinists translate the digital design into machine-readable instructions, known as G-code. The users can create the instructions from scratch, repurpose existing G-code, or use computer-aided manufacturing (CAM) software to generate the code.
For example, here are the steps to create a small gear using a CNC milling machine:
- Design the part: First, create a digital version of the gear using drawing software.
- Write instructions (G-code): Translate the design into machine-readable G-code. These instructions tell the CNC machine how and where to move and what to do at each location.
- Set up the machine: You load your chosen material, like metal or plastic, into the machine. Next, you attach the appropriate cutting tool to the machine’s arm.
- Run the program: Once you have input the G-code instructions, the machine reads the instructions and starts moving the cutting tool. The machine will act like a sculptor as it follows the instructions to shape the material.
- Make the cuts: The cutting tool moves side to side, up and down, and even rotates as it follows the G-code instructions to make precise cuts and shapes.
- Admire the results: After the CNC machine completes its work, you have your finished part. In our example, you’d have a perfectly shaped gear ready for machine use.
The machine can continuously repeat the same process by following the same program, which allows manufacturers to produce consistent, identical parts. Additionally, CNC machines can create intricate shapes that would be difficult to make by hand. This is why manufacturers use CNC to produce complex items such as jewelry, car engine parts, or decorative metal decorations.
Types of CNC Operations
Specific manufacturing needs dictate the type of CNC operations needed. Consequently, each process uses different options and axes’ when positioning the cutting arm, creating a wide range of classifications:
- Milling: CNC milling involves rotating cutting tools to remove material from a workpiece to create a desired shape. It’s like precision sculpting. Milling machines can handle 2D and 3D shapes, making them versatile for aerospace, automotive, and electronics industries.
- Turning: In CNC turning, a workpiece rotates while a cutting tool shapes it. It’s like using a lathe but with computer control for accuracy and consistency. Turning is commonly used for cylindrical parts like shafts and bolts.
- Drilling: CNC drilling machines create precise holes in materials. Think of it as a digital drill press. Metalworkers and woodworkers are likely to use CNC drilling.
- Laser cutting: Lasers offer high precision and can handle complex patterns without cutting entirely through the material. A high-energy laser beam can create elaborate designs in various materials, from metals to plastics.
- Plasma cutting: CNC plasma cutting uses a jet of superheated plasma to cut through electrically conductive materials like metal. It is suited for thicker materials and is often used in metal fabrication and construction because it works quickly.
- Waterjet cutting: This technique uses high-pressure water mixed with abrasive substances to cut through materials of uneven thicknesses. Because it doesn’t use heat, there is no risk of burn marks on the edges. Waterjet cutting excels in managing delicate substances but is also better than plasma cutting at slicing through thick materials.
- Routing: CNC routers are used to hollow out areas of materials, like carving patterns in wood or creating detailed designs on plastic surfaces.
- 3D printing/Additive manufacturing: While not traditionally considered CNC, 3D printing involves additive processes where materials are built layer by layer to create 3D objects. CNC-controlled 3D printers follow digital designs to create complex parts and prototypes.
- Electrical discharge machining (EDM): EDM is primarily used on metal, also known as spark machining. A special liquid removes material when electric power is applied to two points.
See More: What Is Version Control? Meaning, Tools, and Advantages
Computer Numerical Control Considerations
When working with CNC systems, there are several critical considerations manufacturers need to take into account to ensure successful and efficient operations:
- Design and programming: The foundation of CNC begins with designing the part you want to create and then translating that design into the necessary G-code instructions. Design software and CAM programs are crucial in generating accurate and efficient CNC instructions.
- Material selection: Different materials behave differently during CNC operations. The characteristics of the material – like hardness, brittleness, and heat resistance – determine which tool choices, cutting speeds, and feeds are appropriate. Proper material selection ensures successful machining without excessive wear on tools.
- Tool selection and maintenance: Selecting the right cutting tools, end mills, drills, and more is crucial to achieving the desired results. Regular tool maintenance and replacement prevent deterioration in quality and accuracy.
- Workholding: Securing the workpiece properly on the CNC machine’s table or chuck is vital. Effective clamping methods ensure stability during machining. An inefficient grip on the work can lead to misaligned cuts and wasted material.
- Speeds and feeds: Determining the appropriate cutting speeds and feed rates is essential for efficient machining and tool life. Balancing these factors avoids excessive wear on tools and prevents the material from getting damaged.
- Precision and tolerances: CNC machines are known for their high precision, but it is crucial to understand the tolerances needed for a specific part. Over-tolerancing can lead to unnecessary complexity and cost, while under-tolerancing might compromise the part’s functionality.
- Fixture and setup: Proper fixture design and setup ensure that the workpiece is accurately positioned and held during machining. A well-designed fixture reduces the chance of errors and contributes to consistent quality.
- Safety measures: CNC operations involve moving parts, high-speed tools, and sometimes hazardous materials. Implementing safety protocols, protective barriers, and proper operator training is essential to prevent accidents.
- Prototyping and testing: Before starting large-scale production, creating prototypes and conducting test runs can help identify potential issues and optimize the machining process. Small, controlled trial runs conserve time and save resources.
- Quality control: Monitoring the process, regularly inspecting and measuring equipment, and adjusting as necessary during and after CNC operations guarantees the final product meets specifications.
- Workflow optimization: Streamlining the entire CNC workflow, from design to finished part, boosts efficiency. Integrating CAD/CAM software, automating tool changes, and optimizing cutting paths can save time and reduce errors.
See More: What Is Patch Management? Meaning, Process, and Best Practices
Applications of CNC Technology
CNC technology has a wide range of applications across various industries. Key applications include:
- Aerospace industry: CNC technology plays a vital role in manufacturing components for aircraft and spacecraft. Parts like turbine blades, engine components, and structural elements require high precision.
Use cases: Intricate airfoil shapes in jet engine blades for optimal performance - Automotive industry: CNC is extensively used to make automotive parts, from engine blocks to intricate interior components. CNC machining ensures consistent quality and tight fits.
Use cases: Engine components like crankshafts, transmission parts, and cylinder heads - Architecture and construction: CNC technology is applied to create detailed architectural models, intricate facades, and decorative elements for buildings.
Use cases: Fabricating large-scale components like columns, beams, and wall panels with precise patterns and shapes. - Art and sculpture: Artists and sculptors leverage CNC technology to bring their imaginative creations to life. CNC machines allow artists to achieve precision that would be nearly impossible by hand.
Use cases: Carving intricate designs into various materials, including wood, stone, and metal - Electronics industry: The precision and accuracy of CNC technology are crucial for producing electronic components. Printed circuit boards (PCBs), connectors, and housings are manufactured using CNC processes.
Use cases: Electronic circuits require precise traces and drill holes in PCBs - Energy sector: CNC technology is employed in producing components for renewable energy systems. CNC machining ensures the precision required for efficient energy generation and distribution.
Use cases: Wind turbines and solar panels - Healthcare: CNC technology is essential for producing medical implants, prosthetics, and surgical instruments. Customization is a key factor here, as every patient is unique.
Use cases: Dental crowns, orthopedic implants, and surgical instruments - Manufacturing: Creating intricate designs requires precision and fine detail. CNC work reduces manual labor, and allows also for design possibilities that might be impossible to create by hand. CNC is used across many types of manufacturing:
- Jewelry: Jewelers can create unique designs and deliver consistent quality to their customers.
Use cases: Carving intricate patterns and shapes into precious metals and gemstones - Prototyping: CNC technology facilitates rapid prototyping and quick iteration of designs.
Use cases: Creating working prototypes of new consumer products; Testing design modifications to industrial machinery - Tool and die-making: CNC machines are used to create molds, dies, and tooling for various manufacturing processes.
Use cases: Creating consistent and high-quality parts in industries like injection molding, stamping, and die casting - Woodworking and furniture: CNC routers are extensively used in woodworking.
Use cases: Creating intricate patterns, moldings, and custom furniture pieces.
- Jewelry: Jewelers can create unique designs and deliver consistent quality to their customers.
These are just a few examples of the diverse applications of CNC technology across industries. Its ability to produce intricate shapes, maintain high precision, and scale production has led to its widespread adoption, transforming manufacturing processes and enabling the creation of innovative and high-quality products.
CNC Market Outlook
Precedence Research estimates that the global CNC market size was $95 billion in 2002. Experts expect the market to rise to $154 billion by 2023. Regionally, Asia Pacific and North America held the largest market share in 2022, at 36% and 32%, respectively.
Businesses always seek ways to improve efficiency, so implementing CNC processes allows manufacturers to keep up with the demand for mass-produced high-precision products. For example, the average automobile has nearly 2000 parts, including collective parts like engines, gearboxes, radios, and HVAC systems. If you break those parts into individual elements, about 30,000 unique parts are required to build a car. A single CNC machine can produce multiple parts with low effort by loading new G-code or swapping out the cutting tool.
The increasing demand for industrial equipment, such as medical devices, manufacturing equipment, communication devices, and electric vehicles (EV), is driving the growth of the computer numerical control (CNC) machine market.
In addition, escalating demand for semiconductor chips, including graphics- and tensor processing units, is a catalyst for the expansion of the CNC market. CNC processing ensures minimal surface tolerance and enables the creation of the meticulous cylindrical components required by semiconductors.
Sources:
- https://www.marketresearchfuture.com/reports/cnc-machine-market-10107
- https://www.grandviewresearch.com/industry-analysis/computer-numerical-controls-cnc-market
- https://www.precedenceresearch.com/computer-numerical-control-machine-market
- https://www.fortunebusinessinsights.com/industry-reports/computer-numerical-controls-cnc-machine-tools-market-101707
Key Players in the CNC Market
- Amada – Kanagawa, Japan
Manufactures metal processing equipment and machinery, including cutting, forming, shearing, and punching machines. - Hyundai WIA – Changwon-si, South Korea
This division of Hyundai Motor Group manufactures parts and tools for the automotive, defense, and industrial industries. - Komatsu – Tokyo, Japan
Komatsu manufactures heavy equipment for construction, mining, forestry and defense industries, and industrial equipment, including lasers and generators. - Mazak – Ōguchi, Japan
Established in 1919, Mazak builds and manufactures machine tools for CNC processes, including lathes, machining centers, laser systems, and CAD/CAM systems. - Mitsubishi Heavy Industries – Tokyo, Japan
MHI engineers and builds electrical and electronic components for multiple industries, including aerospace, automotive, construction, defense, energy, and shipbuilding. - Okuma – Ōguchi, Japan
Originally a manufacturer of noodle-making machines, Okuma designs and builds CNC machine hardware, software, and machine components. - Sandvik – Stockholm, Sweden
Engineers and manufactures excavation and site preparation solutions, including mining, drilling, rock processing, and metalwork equipment. - Siemens AG – Munich, Germany
Produces products to improve industrial automation, building technologies, healthcare, and energy. - Trumpf – Stuttgart, Germany
This family-owned company supplies machine tools for processing sheet metal. Concurrently, it also manufactures carbon dioxide and solid-state lasers for laser and plasma cutting.
Takeaway
Current CNC technology is capable of remarkable accuracy, which enables us to create complex parts with minimal human intervention. Additionally, CNC systems are becoming more user-friendly, affordable, and accessible. Innovators are finding use cases beyond those of the traditional manufacturing giants, including its adaptation as a hobby.
Looking forward, the future of CNC promises an increased level of automation as it incorporates connectivity and advanced technology. Industry 4.0 will require features that allow instant monitoring, predicting maintenance needs, and constantly improving processes using live data. Artificial intelligence and machine learning will refine CNC operations, improving efficiency and adaptability. As additive manufacturing intersects with CNC, new rapid prototyping and customized production applications will emerge, revolutionizing how we create and manufacture.
MORE ON MANUFACTURING TECHNOLOGY
