Definition of CNC Machine Terms
Computer Numerical Control (CNC) is a method used to control machine tools through the use of computer programs. CNC machines use computers that interpret machine control language and control cutting tools, such as drill bits and saws, to create patterns, curves and shapes.
CNC machines can cut almost any material, and are used in many industries including the aerospace, automotive and manufacturing industries. Below are some of the terms used to describe common CNC machine components and functionalities.
Axis: The line along which the cutting tool is moved. The three common axes in a CNC machine are the X-axis (side-to-side movement), the Y-axis (up-and-down movement), and the Z-axis (depth of cut).
Chuck: A mechanical device that holds the cutting tool in place during its operation. A 3-jaw chuck is the most common type used on CNC machines.
Feed Rate: The speed at which the cutting tool is moved across the workpiece.
G code: The code language used by CNC machines to control their movement.
Spindle: The part of the machine that rotates the cutting tool.
Table: The part of the CNC machine that holds the workpiece in place during cutting.
Tool Offset: The amount by which the cutting tool must be offset in order to account for any changes in its relative position following a tool change.
CNC Gantry Machine: A CNC machine that utilizes two parallel columns and acts as a bridge between them to move the cutting tool.
Motion Control System: The component of a CNC machine that is responsible for controlling the speed and direction of the cutting tool’s movement.
Zero Return Code: An instruction used to reset the position of the cutting tool in relation to the workpiece.
Tool Wear Compensation: A type of control system that can compensate for wear on the cutting tool by adjusting the cutting parameters as needed.
Look-Ahead: A feature of CNC machines that allows for the calculation of future cutting motions based on the current cutting parameters.
Machine Feed: The force applied to the cutting tool during its operation.
Feedback Signal: The signal sent from the motion control system to the cutting tool in order to monitor its speed and/or position.
CNC Programmer: A skilled professional who is responsible for writing the code that will run the CNC machine.
CAM Software: Computer-aided manufacturing software that can be used to create programs for CNC machines without the need for a programmer.
Flood Coolant: A type of coolant that is delivered to the cutting tool through a nozzle, to help keep the tool cool and reduce friction during cutting.
Work Offsets: The programmable parameters that determine the location of the part relative to the cutting tool.
Macro Programming: A method of programming used to reduce the number of instructions that need to be written in order to control the motion of the cutting tool.
Backplotting: The process of ‘playing back’ a CNC program in order to visualize the movement of the cutting tool during its operation.
