# Glossary

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### Absolute Coordinates

Absolute coordinates are expressed relative to a fixed position, whereas relative coordinates are expressed relative to the cutting tool’s current position.

### Accuracy

Accuracy is the difference between the desired and actual dimension of a measurement.

### Auto Tool Changer (ATC)

An auto tool changer (ATC) switches between multiple toolheads without stopping the production cycle for additional setup.

### Axes (x-axis, y-axis, z-axis)

An axis is an imaginary line used to measure distances and describe positions within a cartesian coordinate system. The X-axis and Y-axis are typically parallel to the ground (horizontal) and perpendicular to each other. The Z-axis is typically perpendicular to both the X-axis and Y-axis (vertical).

### Ballscrew

Ballscrews drive an axis of a CNC machine using a leadscrew and ball bearings for low friction, high efficiency, precision motion.

### Block

A block is the smallest unit of G-Code representing an operation that a CNC machine could perform. Printed, a block is represented as a line of text.

### Boring

Boring is the process of enlarging a pre-existing hole using a single-point tool.

### Cartesian Coordinate System

A cartesian coordinate system uniquely describes each location in a plane with a pair of numbers measured in the same unit of length. Named for philosopher and mathematician Rene Descartes.

### Chamfer

A chamber is beveling applied to smooth an edge.

### Chip

Chips are unwanted pieces material removed during manufacturing, especially metal.

### Collet

A collet is a kind of clamp used to hold a tool or workpiece during manufacturing.

### Computer Assisted Design (CAD)

Computer Assisted Design (CAD) is the use of computer software to design objects to be manufactured.

### Coordinates

Coordinates are sets of numbers that describe positions within a defined space.

### Computer-Aided Manufacturing (CAM)

Computer-Aided Manufacturing (CAM) is the use of computer software to control machine tools in the manufacturing of workpieces.

### Cycle Time

Cycle time is the duration a machine works on a single part.

### Deflection

Deflection is the shift in position or vibration of a workpiece due to insufficient hold, which can cause inaccuracy.

### Depth of Cut (DOC)

Depth of cut (DOC) refers to the amount of material removed on each pass of the tool.

### Dimension

A dimension is the measurement specified in the design document for a feature of a part.

### Drilling

Drilling is the process of penetrating the surface of a workpiece with a multi-point tool to make a round hole.

### Emergency Stop (E-STOP)

An emergency stop (E-STOP) is a switch that, when activated, immediately halts all machine motion and prevents the machine from running.

### Feedrate

Feedrate measures the motion of the tool relative to the workpiece during cutting, whereas speed mesures how fast the spindle rotates the cutting tool.

### Frame

The frame is the structural component of a CNC machine that supports all compontents related to linear motion, securing workpieces, and spoilboards.

### Gantry

The gantry is a structural component of a CNC machine that travels along one horizontal axis and supports the spindle as it travels along the perpendicular horizontal axis.

### G-Code

G-Code is a programming language used by CNC machines to describe and execute various motions through a defined geometrical space. G-Code also defines various offsets and sub-routines, like tool changes.

### Jogging

Jogging is the manual operation that causes the machine to move along an axis.

### Limit Switch

Limit switches signal when the machine has reached the farthest position along an axis.

### Linear Guide Rail

Linear guide rails provide a straight track for low-friction high-precision motion.

### Machine Zero (home)

Machine zero (home) is the farthest positive position along each axis.

### Offset

An offset is a pre-defined distance used by the CNC controller to account for variable like tool length and wear.

### Origin

The origin is the point from which a set of coordinates references its position. For absolute coordinates, the origin is a fixed location, whereas relative coordinates usually reference the current location.

### Part Program

A part program is the series of numerical instructions the CNC machine uses to produce a specific part.

### Relative Coordinates

Relative coordinates describe a position with reference to a non-fixed origin point, whereas absolute coordinates reference a fixed origin point.

### Repeatability

Repeatability is the ability of a CNC machine to accurately reproduce a part continuously.

### Router

A router is a tool used to hollow out an area in the face of a workpiece.

### Servomotor (servo)

A servomotor is an actuator allowing for motion with precise control of position, velocity, and acceleration.

### Setup

Setup is the process of preparing the CNC machine and workpiece for production, including securing the workpiece and installing tools.

### Shroud

The shroud is a guard or barrier that wraps around the tool, often attached to a dust collector.

### Speed

Speed is the rate at which the spindle turns the cutting tool.

### Spindle

The spindle is a motor that turns the cutting tool.

### Spoilboard

A spoilboard is the replaceable table surface which allows the cutting tool to pass through the workpiece without damaging the machine’s frame.

### Stepper Motor

A stepper motor rotates through a set number of discrete steps based on how many electrical pulses it receives. Similar to a servo, but with less precise motion.

### Tool Offset

A tool offset is the pre-defined measurement of the distance between the position of the spindle and the cutting edge of the tool along the Z-axis.

### Tool Path (toolpath)

The tool path is the series of coordinates the machine moves through to complete an operation.

### Touch Off

Touch off is the process of defining the position of a workpiece or tool length by touching the tool to the workpiece or a known location.

### Trial Run (dry run)

A trial run (dry run) executes the part program without any part in the machine to confirm the tool path.

### T-Slot

T-slot table surfaces provide standardized aluminum tracks that accept various fasteners (clamps, etc.) to secure the workpiece.

### USB

USB, or universal serial bus, is a common port standard used to transfer data from various storage devices, including thumb drives and PCs.

### Vacuum Pump

Vacuum pumps provide suction to secure workpieces during manufacturing.

### Workpiece

The workpiece is the object being manufactured and/or the stock material used to manufacturer it.