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Computer numerical control

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"text": "Computer numerical control, commonly known as CNC, is the automated management of machine tools through computer systems.

CNC machine
CNC machine

This technology represents an evolution of numerical control, or NC. In early NC systems, data storage media like punched cards or punched tape directly managed the tools. Modern CNC has largely replaced NC because it allows for easier programming and real-time adjustments. As computing costs have declined, CNC has become the standard for high-precision manufacturing. It allows for much higher productivity in repetitive production compared to manual or mechanical control.

Cnc lathe
Cnc lathe

\n\nThe manufacturing process begins with a digital design. Engineers first use computer-aided design, or CAD, software to define the mechanical dimensions of a part. Once the design is finished, computer-aided manufacturing, or CAM, software translates those dimensions into manufacturing directives. These directives must then be converted into specific commands for a particular machine using post-processor software. The machine executes these instructions using sequential programs, often written in G-code or M-code. For 3D printers, the software must \"slice\" the part into layers before generating these instructions.

\n\nTo create a physical object, the CNC machine moves tools along specific axes. Most systems control at least three axes: X and Y for horizontal movement, and Z for depth. These movements are driven by motors to ensure high accuracy. Some older designs used motors through step-down gears, but modern machines use direct-drive stepper motors or servo motors. Commercial metalworking machines typically use closed-loop controls to maintain speed and repeatability. This ensures the final part meets every specification and tolerance defined in the original CAD drawing.

Waterjet cutting machine
Waterjet cutting machine

\n\nCNC technology is not limited to a single type of machine. A CNC mill moves a spindle or workpiece to various locations and depths. These machines can have three to six axes and perform tasks like drilling or tapping. A CNC lathe, however, rotates the workpiece while cutting it. Modern lathes often include \"live tooling\" for milling or a sub-spindle to machine the back side of a part. Other specialized machines include plasma cutters, which use hot gas to melt metal, and waterjet cutters.

Waterjet cutting machine
Waterjet cutting machine

A waterjet cutter can use water at pressures around 60,000 PSI, sometimes mixed with abrasive garnet powder, to slice through stone or metal.

Retro Systems Waterjet
Retro Systems Waterjet

\n\nThere are also highly specialized methods like electric discharge machining, or EDM. EDM uses electrical discharges, or sparks, to erode material from a workpiece. In \"sinker\" EDM, an electrode creates a negative shape in the part, which is a relatively slow process. In "wire" EDM, a thin conductive brass wire acts as the electrode to cut complex profiles. Another method is the plasma cutter, which turns gas into plasma using an electrical arc. This plasma is hot enough to melt material and blow the molten metal away from the cut.

EDMWorkpiece
EDMWorkpiece

\n\nThe history of these machines began in the 1940s and 1950s. The first NC machines were modified existing tools that used motors to follow points from punched tape. These early servomechanisms were later improved by adding analog and digital computers. This progression led to the highly automated systems used in modern factories today. Today, CNC is used for almost any process involving movement. This includes laser cutting, welding, sewing, and even fabric cutting.

Cortadora Laser - FabLAB Newton
Cortadora Laser - FabLAB Newton

\n\nModern manufacturing is moving toward even more advanced integration. Engineers are now combining traditional subtractive manufacturing with additive manufacturing, known as 3D printing. This new method is called hybrid additive subtractive manufacturing, or HASM. There is also a growing trend of using artificial intelligence and large numbers of sensors. This combination aims to achieve flexible manufacturing through real-time supervision. These advancements ensure that CNC technology remains at the center of industrial efficiency and quality.

Laser engraved wood
Laser engraved wood

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🖼️ Images & Media (10)
File:CNC machine.jpg
CNC machine.jpg
File:Wheel Machining.jpg
Wheel Machining.jpg
File:Cnc lathe.png
Cnc lathe.png
CNC Plasma Cutting.ogv
File:EDMWorkpiece.jpg
EDMWorkpiece.jpg
File:Waterjet cutting machine.jpg
Waterjet cutting machine.jpg
File:Punch machine.jpg
Punch machine.jpg
File:Cortadora Laser - FabLAB Newton.jpg
Cortadora Laser - FabLAB Newton.jpg
File:Retro Systems Waterjet.jpg
Retro Systems Waterjet.jpg
Laser engraved wood.webp
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