cnc basic key terms
A referencing method used with coordinate systems in which the coordinates of all positions are referenced from the origin (X0, Y0, Z0).
Commanded by the G-codes G2 or G3, a type of motion that causes the cutter’s path to travel in an arc so that CNC machines can cut full or partial circles.
Circular interpolation
A referencing method used with coordinate systems which specifies a distance from the current position to the next position instead of a location related to the initial origin.
Incremental positioning system
CNC programming codes used to turn on and off miscellaneous functions.
M-codes
A device used in some CNC machines to automatically load, unload, and store tools.
Automatic tool changer (ATC)
A special type of MCU function developed to simplify the machine programming process in which the operator selects the intended type of machining operation from an on-screen menu and the machine prompts the programmer with a series of questions.
Conversational programming
A modernized version of ways that are sealed, have pressurized lubrication systems, and contain low friction ball bearings.
Linear guides
Machine codes that remain active until cancelled or overridden.
Modal
A screw and nut assembly with steel balls in place of threads which can achieve high efficiency and zero backlash in computerized numerical control machines.
Ball screw
The sensor portion of a CNC machine’s servo motor that works by recording the amount of rotation a motor makes (in degrees), which provides feedback to the machine control to ensure the desired amount of movement is obtained.
Encoder
Designated by the G-code G1, CNC motion used to move the tool in a straight line along one or more machine axis.
Linear interpolation
A coordinate system used to identify locations by defining both an angle and a distance (like a vector in mathematics) from the origin to a specific location.
Polar coordinate system
In the word address programming system, a group of program words that appear on the same line and are to be executed at the same time.
Block
The semicolon character at the end of a block of CNC code that instructs the MCU to move on to the next block.
End of block
Sometimes simply called a “control,” the system of a CNC machine that interprets the program and then uses the information to control machine functions and control axis motion.
Machine control unit, or MCU
Designated by the G-code G0, a type of CNC machine motion used to quickly position tools near the workpiece before beginning a machining operation.
Rapid traverse
A computerized numerical control (CNC) lathe equipped with an automatic tool changer.
Turning center
Two- or three-dimensional systems that use X and Y or X, Y, and Z values for location.
Rectangular or Cartesian coordinate system
CNC programming codes that prepare a machine to engage in a particular mode for machining; for instance, a G1 code tells the machine to feed in a straight line, or linear motion.
G-codes
A computerized numerical control (CNC) mill equipped with an automatic tool changer.
Machining center
A hybrid electric motor that is half motor/half position sensor, which can both provide the power to move a machine axis and track how far the axis has moved.
Servo motor
A style of programming in which instructions are written in a code or format that can be understood and executed by a CNC machine tool.
Word address