Introduction to Numerical Control
– Numerical control (NC), also known as computer numerical control (CNC), automates the control of tools in machining.
– CNC is used to operate tools such as drills, lathes, mills, grinders, routers, and 3D printers.
– It transforms materials like metal, plastic, wood, ceramic, stone, or composite into specific shapes.
– CNC machines follow programmed instructions and do not require manual control during machining.
– CNC machines are controlled by computers and can be programmed using G-code and M-code instructions.
Parts and Programming of CNC Machines
– CNC machines have motorized maneuverable tools and platforms controlled by computers.
– Instructions for CNC machines are delivered in the form of sequential programs.
– These programs can be written by a person or generated by CAD or CAM software.
– 3D printers also use G-code for slicing and generating instructions.
– Modern CNC systems have highly automated design and manufacturing processes.
History and Applications of CNC
– The first CNC machines were developed in the 1940s and 1950s, revolutionizing machining processes.
– Analog and digital computers were later integrated into CNC machines.
– CNC-like systems are now used in various processes like laser cutting, welding, bending, and more.
– CNC has become extensively used in the manufacturing field, improving the quality and efficiency of the industry.
– The latest trends in CNC include the combination of subtractive manufacturing with additive manufacturing and the integration of AI and sensors for flexible manufacturing.
Examples of CNC Machines
– CNC mills are used for various milling operations like face milling, tapping, and drilling.
– CNC lathes cut workpieces while they are rotated, using indexable tools and drills.
– CNC plasma cutters are used to cut materials, especially steel and other metals.
– Electric discharge machining (EDM) uses electrical discharges to obtain the desired shape.
– Multi-spindle machines are highly efficient for mass production, utilizing a diversified set of tooling.
Other CNC Processes and Machines
– Spindle machines have multiple spindles on a rotating drum and are driven by gears.
– Wire EDM uses spark erosion to machine electrically conductive materials.
– Sinker EDM uses an electrode and workpiece submerged in dielectric fluid to generate sparks.
– Water jet cutters use a high-velocity jet of water or a mixture of water and abrasive substance to cut materials.
– Punch presses are used to rapidly punch holes and cut thin materials, with different variants available.
Note: The content provided has been grouped based on the similarity of concepts and topics. The grouping may not cover all possible combinations, but it aims to provide a comprehensive organization of the information. Source: https://en.wikipedia.org/wiki/CNC
In machining, numerical control, also called computer numerical control (CNC), is the automated control of tools by means of a computer. It is used to operate tools such as drills, lathes, mills, grinders, routers and 3D printers. CNC transforms a piece of material (metal, plastic, wood, ceramic, stone, or composite) into a specified shape by following coded programmed instructions and without a manual operator directly controlling the machining operation.
A CNC machine is a motorized maneuverable tool and often a motorized maneuverable platform, which are both controlled by a computer, according to specific input instructions. Instructions are delivered to a CNC machine in the form of a sequential program of machine control instructions such as G-code and M-code, and then executed. The program can be written by a person or, far more often, generated by graphical computer-aided design (CAD) or computer-aided manufacturing (CAM) software. In the case of 3D printers, the part to be printed is "sliced" before the instructions (or the program) are generated. 3D printers also use G-Code.
CNC offers greatly increased productivity over non-computerized machining for repetitive production, where the machine must be manually controlled (e.g. using devices such as hand wheels or levers) or mechanically controlled by pre-fabricated pattern guides (see pantograph mill). However, these advantages come at significant cost in terms of both capital expenditure and job setup time. For some prototyping and small batch jobs, a good machine operator can have parts finished to a high standard whilst a CNC workflow is still in setup.
In modern CNC systems, the design of a mechanical part and its manufacturing program are highly automated. The part's mechanical dimensions are defined using CAD software and then translated into manufacturing directives by CAM software. The resulting directives are transformed (by "post processor" software) into the specific commands necessary for a particular machine to produce the component and then are loaded into the CNC machine.
Since any particular component might require the use of several different tools – drills, saws, etc. – modern machines often combine multiple tools into a single "cell". In other installations, several different machines are used with an external controller and human or robotic operators that move the component from machine to machine. In either case, the series of steps needed to produce any part is highly automated and produces a part that meets every specification in the original CAD drawing, where each specification includes a tolerance.
