Introduction to Multi-Axis CNC Machines 217

3+2 machining

A 5-axis machining style in which the table rotates to a specific angle, then remains fixed while the spindle cuts the workpiece. 3+2 machining works well for large, less complex parts.

3-axis mills

A milling machine that moves linearly along three axes. 3-axis mills only move linearly on the X, Y, and Z axes, while multi-axis machining centers also move rotationally.

5-axis CNC machine

A multi-axis CNC machine that has two rotational axes and three linear axes. 5-axis CNC machines are the most common type of multi-axis machining center.

A axis

One of three rotational axes. The A axis rotates around the X linear axis.

additive manufacturing

AM. The process of joining or solidifying materials to make an object based on a three-dimensional computer model. Additive manufacturing methods typically build up layers of material to create an object.

advanced manufacturing

The use of innovative technology and processes to improve the manufacturing of products. Advanced manufacturing technologies include additive and smart manufacturing.

axes

An imaginary line or circle that is used to define the position of an object in space. Axes can be linear or rotational.

B axis

One of three rotational axes. The B axis rotates around the Y linear axis.

C axis

One of three rotational axes. The C axis rotates around the Z linear axis.

Cartesian coordinate system

A numerical system that describes the location of an object by expressing its distance from a fixed position along three perpendicular linear axes. The Cartesian coordinate system is used to program machining positions on a CNC machine.

changeover

The process of switching a machine from one part setup or process to another. Changeover time is greatly reduced by hybrid manufacturing with multi-axis CNC machines.

CNC

Computer numerical control. A combination of software and hardware that directs the operation of a machine. CNC machines are much more precise than their manual counterparts.

collisions

An event when the cutting tool makes undesired contact with the workpiece or other machine components. Collisions are caused by tool interference and poorly designed features like high walls.

column

The rigid, vertical support section of a multi-axis CNC machine. Columns support and suspend the spindle and tools over the workpiece.

computer numerical control

CNC. A combination of software and hardware that directs the operation of a machine. Computer numerical control machines are much more precise than their manual counterparts.

computer-aided design

CAD. A computer software program that aids in the automated design and technical precision drawing of a part, product, process, or building. Computer-aided design can create three-dimensional digital models used for digital twins.

contours

A curved surface, dimension, or feature that is cut into a workpiece. Complex contours can be difficult for conventional CNC mills and lathes to cut.

digital twins

A virtual representation of a physical object, such as a part or machine. A digital twin evolves with the object throughout its lifecycle.

directed energy deposition

DED. An additive manufacturing process in which focused thermal energy is used to melt materials as they are fed or blown through a nozzle. Directed energy deposition is often used with powdered or wire metal.

holemaking

The process of machining a hole into the surface of a workpiece. Holemaking operations include drilling, boring, reaming, and tapping.

horizontal machining centers

A machining center with a spindle that is parallel to the floor. Horizontal machining centers are less common than vertical machining centers.

human error

A failure or flaw in the machining process that occurs as a result of an operator being tired, lacking fine motor skills, or losing concentration. Human error is greatly reduced by multi-axis CNC machining because it requires little human intervention.

hybrid manufacturing

A process that uses both traditional and additive manufacturing to create a finished part. Hybrid manufacturing can involve either using a traditional manufacturing process on a mostly additively manufactured part or vice versa.

lathes

A machine tool commonly used to create cylindrical forms. A lathe holds a cylindrical workpiece on one or both ends while the cutting tool is gradually passed along the surface of the rotating part.

lights-out manufacturing

Fully automated manufacturing that can operate independently in a facility without any employees on site. Lights-out manufacturing allows facilities to operate for extended hours while reducing labor costs.

linear

Moving in a straight line along a single axis. Linear movement of an object is described by the X, Y, and Z axes.

machining

The process of removing material to create a part. Machining processes include turning, milling, drilling, and grinding.

machining centers

An advanced CNC machine that can perform multiple machining operations at the same location with a variety of tools. Machining centers include multi-axis CNC machines.

micrometers

An extremely small measurement equaling one-millionth of a meter. Micrometers are used to measure the precision of multi-axis CNC machining centers.

milling

A machining operation in which a cutting tool rotates against a workpiece to create flat surfaces, grooves, or pockets. On multi-axis machining centers, milling and turning operations can occur simultaneously.

Multi-axis CNC machines

A machining center that has four or more linear and rotational axes. Multi-axis CNC machines, or multitasking machines, combine the functions of a mill and a lathe.

multitasking machines

A machining center that has four or more linear and rotational axes. Multitasking machines, or multi-axis CNC machines, combine the functions of a mill and a lathe.

nutating head

A style of 5-axis CNC machine in which the spindle performs most of the rotation. Nutating head, or swivel-rotate, machines are best for large, heavy parts.

origin

A fixed, central point in the Cartesian coordinate system where the three X, Y, and Z axes intersect. The origin has a numerical value of zero.

parallel

Extending in the same direction and equally distant from one another at all points. On a horizontal machining center, the spindle is oriented parallel to the worktable.

part programs

A series of alpha-numeric instructions that direct a CNC machine to perform the necessary sequence of operations to machine a specific workpiece. Multiple part programs can be stored in a CNC at one time.

perpendicular

Intersecting another line or plane at a right angle. On a vertical machining center, the spindle is oriented perpendicular to the floor.

post-processing

A procedure used to clean, improve, or otherwise finish a part after it has been manufactured. Post-processing procedures include abrasive finishing, heat treating, and painting.

rotation

Travel around a circular axis. On a 5-axis CNC machine, rotation describes movement by either the spindle or the worktable around the C axis.

rotational

Moving in a circular path around an axis. Rotational movement of an object is described by the A, B, and C axes.

semi-autonomously

The ability of a system to operate without constant human intervention. Multi-axis machining centers semi-autonomously, or independently, complete cutting tasks without human supervision.

sensors

A device that detects the presence or absence of an object, or certain properties of that object, and provides feedback. Common sensor applications include parts detection, counting, and positioning, motion, speed, feed, and jam control, and parts diverting.

servomotor

A type of motor used in applications that require precise positioning. A servomotor contained in the head of a multi-axis CNC machine controls the power and movement of the spindle.

setup

All the necessary preparation of tooling and fixturing that occurs on a machine before a cutting operation begins. Setup includes the positioning of the tool, the milling machine, and the workpiece.

simulations

A computer-driven technology used to duplicate real-world and real-time situations in order to evaluate behavior under real conditions. Simulation can test the behavior of a manufacturing process before it is used to make an actual product.

simultaneous machining

A 5-axis machining style in which the spindle and table can move along all five axes at any time during the cutting process. Simultaneous machining is best for complex parts.

smart manufacturing

Technologically integrated manufacturing that creates and uses data in real time to address the needs of the factory, supplier, and customer. Smart manufacturing is an advancement of traditional manufacturing automation.

spindle

A rotating component of a multi-axis CNC machine that holds the cutting tool. The spindle can be oriented horizontally or vertically and can move along a combination of linear and rotational axes, depending on the configuration of the machining center.

spindle head

The part of a multi-axis CNC machine that controls the spindle. The spindle head is attached to the column and includes a servomotor and power transmission system that control the motion of the spindle.

spindle/spindle

An axis configuration in which both rotational axes are located in the spindle of a 5-axis CNC machine. Spindle/spindle machines allow for the greatest amount of cutting tool movement.

subtractive manufacturing

The process of removing material from an existing object to create its desired final shape. Subtractive manufacturing includes milling, turning, drilling, and grinding.

Swivel-rotate

A style of 5-axis CNC machine in which the spindle performs most of the rotation. Swivel-rotate, or nutating head, machines are best for large, heavy parts.

table

The part of a multi-axis CNC machine that supports the workpiece. The table, or worktable, can move along a combination of linear and rotational axes, depending on the configuration of the machine.

Table/spindle

An axis configuration in which one rotational axis is located in the table and the other is located in the spindle of a 5-axis CNC machine. Table/spindle machines are best for complex, large, or heavy parts.

table/table

An axis configuration in which both rotational axes are located in the table of a 5-axis CNC machine. Table/table machines are best for cutting large parts.

tilt

Swing or change in angle. On a 5-axis CNC machine, tilt refers to the angle at which the part and cutting tool contact each other.

tolerance

An unwanted but acceptable variation or deviation from a desired dimension of a part. Tolerances indicate the allowable difference between a physical feature and its intended design.

tool interference

An undesirable operating condition for a multi-axis CNC machine that occurs when parts of the spindle come into contact with a vise or other machine parts. Tool interference can damage the workpiece or misalign the spindle.

tool turret

A multi-axis CNC machine component that holds a number of cutting tools. The tool turret rotates the spindle to index tools in the cutting position.

toolchanger

A device on a multi-axis CNC machine that automatically switches between preloaded tools when activated by a part program. Toolchangers allow many cutting tools to be used in a single operation.

toolpath

The course followed by the tool as it creates the workpiece. Toolpaths are described by a series of coordinate positions.

trunnion

A style of 5-axis CNC machine in which the worktable performs most of the rotation. Trunnion machines are best for batches of parts and parts with very complex curves.

turning

A machining operation in which a workpiece rotates against a cutting tool to create a cylindrical part. On multi-axis machining centers, turning and milling operations can occur simultaneously.

undercuts

A recessed feature that cannot be cut or accessed by a conventional cutting tool. Undercuts include complex contours and curved holes.

vertical machining centers

A machining center with a spindle that is perpendicular to the floor. Vertical machining center worktables are parallel to the ground.

vise

A workholding device with two jaws that grip and hold a workpiece in place. Vises on multi-axis machining centers keep parts in a fixed position while the worktable and spindle move.

ways

A set of parallel tracks along which the worktable moves. The ways enable linear movement of the worktable on some multi-axis machining centers.

workpiece

A part that is in the process of being machined. A workpiece may be subject to cutting, grinding, forming, welding, or other operations to produce a finished part.

worktable

The part of a multi-axis CNC machine that supports the workpiece. The worktable, or table, can move along a combination of linear and rotational axes, depending on the configuration of the machine.

X axis

One of three linear axes. The X axis runs side-to-side on a vertical machining center and front-to-back on a horizontal machining center.

Y axis

One of three linear axes. The Y axis runs front-to-back on a vertical machining center and vertically on a horizontal machining center.

Z axis

One of three linear axes. The Z axis runs vertically on a vertical machining center and side-to-side on a horizontal machining center.