Glossary

A

auxiliary command A control function such as tool change or machine table rotation. These commands may be interpreted by a specific post-processor.
axial machining operation Operation in which machining is done along a single axis and is mainly intended for hole making (drilling, counter boring, and so on).

B

back and forth Machining in which motion is done alternately in one direction then the other.
bottom plane A planar geometric element that represents the bottom surface of an area to machine. It is normal to the tool axis.

C

climb milling Milling in which the advancing tool rotates down into the material. Chips of cut material tend to be thrown behind the tool, which results in a good surface finish.
conventional milling Milling in which the advancing tool rotates up into the material. Chips of cut material tend to be carried around with the tool, which often impairs a good surface finish.

D

DOF degree of freedom
DPM Digital Process for Manufacturing

E

External axes machines These machines have 5 primary axes for machining and 1 to 3 peripheral or external axes for part positioning.

F

facing operation A surfacing operation in which material is removed in one cut or several axial cuts of equal depth according to a pre-defined machining strategy. Boundaries of the planar area to be machined are soft.
fault Types of faults in material removal simulation are gouge, undercut, and tool clash
feedrate Rate at which a cutter advances into a work piece.
fixture Elements used to secure or support the workpiece on a machine.

G

gouge Area where the tool has removed too much material from the workpiece.

H

hard A geometric element (such as a boundary or a bottom face) that the tool cannot pass beyond.
high speed milling (HSM) Functionality that is supported for Pocketing and Facing operations in which corners and transitions in the tool path are rounded to ensure a smooth and continuous cutting effort.

M

machine rotation An auxiliary command in the program that corresponds to a rotation of the machine table.
machining activity Machining activities are items under the process node in NC machining process documents.  These activities include part operations, manufacturing programs, or a single machining operations.
machining axis system Reference axis system in which coordinates of points of the tool path are given.
machining feature A feature instance representing a volume of material to be removed, a machining axis, tolerances, and other technological attributes. These features may be hole type or milling type.
manufacturing process Defines the sequence of part operations necessary for the complete manufacture of a part.
manufacturing program Describes the processing order of the NC entities that are taken into account for tool path computation: machining operations, auxiliary commands and PP instructions.
manufacturing view The set of machining features defined in the part operation.
MCD Machine Controller Data, ISO code used for non-tool-path-based simulation.
modification range This value is set using Tools>Options>Machining Tool Path Simulation>Simulation.  It lists the number of segments users want made available for change (when they select Modify Tool Path), or the number of segments users want to see (when they select Partial Simulation).
multi-level operation Milling operation (such as Pocketing or Profile Contouring) that is done in a series of axial cuts.

O

offset Specifies a virtual displacement of a reference geometric element in an operation (such as the offset on the bottom plane of a pocket, for example).
one way Machining in which motion is always done in the same direction.

P

parallel axes machine A machine with parts that can move in parallel.
part operation Links all the operations necessary for machining a part based on a unique part registration on a machine. The part operation links these operations with the associated fixture and set-up entities.
peripheral axes machine See external axes machine.
pocket An area to be machined that is defined by a closed boundary and a bottom plane. The pocket boundary may be either open or closed. The pocket definition may also include a top plane and one or more islands.
pocketing operation A machining operation in which material is removed from a pocket in one or several axial cuts of equal depth according to a pre-defined machining strategy.
The tool path style is either Inward helical, Outward helical or Back and forth.
point-to-point operation A milling operation in which the tool moves in straight line segments between user-defined points.
PP instruction Instructions that control certain functions that are auxiliary to the tool-part relationship. They may be interpreted by a specific post processor.
PPR Process Product Resources.

R

remaining material Area where the tool has left too much material on the workpiece.

S

safety plane A plane normal to the tool axis in which the tool tip can move or remain a clearance distance away from the workpiece, fixture, or machine.
segment See tool path segment.
set up Describes how the part, stock and fixture are positioned on the machine.
soft A geometric element (such as a boundary or a bottom face) that the tool can pass beyond.
spindle speed The angular speed of the machine spindle.
Measured in linear or angular units (m/min or rev/min, for example).
stock Workpiece prior to machining by the operations of a part operation.

T

thickness Specifies a thickness of material to be removed by machining.
top plane A planar geometric element that represents the top surface of an area to machine. It is always normal to the associated tool's rotational axis.
tool axis Center line of the cutter.
tool change An auxiliary command in the program that corresponds to a change of tool.
tool clash Area where the tool collided with the workpiece during a rapid move.
tool path The path that the center of the tool tip follows during a machining operation.
tool path point/line The graphic elements used to represent the tool path. Each line represents one segment (motion) and consists of start and end points.
tool path segment A segment is a line represents that represents a motion, and consists of start and end points.  The segment is not based on step size.  The Modification Range option comprises segments.
tool path trace See also, tool path. In NC Machine Tool Simulation, the tool path can be represented on the geometrical data by the tool path trace.  One segment of the tool path is drawn at a time, immediately before machine motion, and is not based on step size.
total depth The total depth including breakthrough distance that is machined in a hole making operation.

U

undercut Area where the tool has left material behind on the workpiece.

W

WPC file This is the file format for data resulting from a material removal session. A typical ascii WPC file contains the number of faces/edges available in the solid and all the vertex information forming each of the triangles in the solid.

Z

zig zag Machining in which motion is done alternately in one direction then the other.