Open-loop control works as long as the forces are kept small enough and speeds are not too great. The position of the tool is driven by direct-drive stepper motors or servo motors in order to provide highly accurate movements, or in older designs, motors through a series of step-down gears. Motion is controlling multiple axes, normally at least two (X and Y), and a tool spindle that moves in the Z (depth). 6 Numerical precision and equipment backlash.In either case, the series of steps needed to produce any part is highly automated and produces a part that closely matches the original CAD drawing. In other installations, a number of different machines are used with an external controller and human or robotic operators that move the component from machine to machine. – modern machines often combine multiple tools into a single 'cell'. Since any particular component might require the use of a number of different tools – drills, saws, etc.

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. The part's mechanical dimensions are defined using CAD software and then translated into manufacturing directives by computer-aided manufacturing (CAM) software. In modern CNC systems, the design of a mechanical part and its manufacturing program is highly automated. using devices such as hand wheels or levers) or mechanically controlled by pre-fabricated pattern guides ( cams). 3D printers also use G-Code.ĬNC is a vast improvement over non-computerized machining that must be manually controlled (e.g. In the case of 3D printers, the part to be printed is 'sliced', before the instructions (or the program) is generated. The program can be written by a person or, far more often, generated by graphical computer-aided design (CAD) software and/or computer aided manufacturing (CAM) software. 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, then executed. A CNC machine processes a piece of material (metal, plastic, wood, ceramic, or composite) to meet specifications by following a coded programmed instruction and without a manual operator directly controlling the machining operation.Ī 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. Numerical control (also computer numerical control, and commonly called CNC) is the automated control of machining tools (such as drills, lathes, mills and 3D printers) by means of a computer.

Cnc machine codes list