# Glossary

## A

approach The part of a tool path that ends where the tool begins to cut the material
approach feedrate The speed of linear advancement of the tool during its approach, before cutting.

## C

climb milling A cutting mode where the front of the tool (advancing in the machining direction) cuts into the material first.

check element Geometry that represents material that is not to be machined in an operation. It often represents a clamp that holds the part to machine in place.
contour-driven machining This type of machining uses  a contour as guide. There are three types of contour driven machining:
• parallel contours where the tool sweeps out an area by following progressively distant (or closer) parallel offsets of a given guide contour.
• between contours where the tool sweeps between two guide contours along a tool path that is obtained by interpolating between the guide contours. The ends of each pass lie on two stop contours.
• spine contour where the tool sweeps across a contour in perpendicular planes.
conventional milling A cutting mode where the back of the tool (advancing in the machining direction) cuts into the material first. See Climb milling.
cut depth The maximum depth of the cut effected by the tool at each pass.

## F

feedrate The speed of linear advancement of the tool into the material while cutting.
frontal wall An area of the part surface that forms an inclined wall that the advancing tool will climb or descend.

## G

guide contour A contour used to guide the tool during an operation.

## I

imposed plane A plane that  the tool must pass through. This option is useful for machining parts that have grooves or steps and when you want to make sure that these areas are cut.
inner point The point where the tool will start cutting in a roughing operation when the surface to machine has pockets.

## L

lateral wall An area of the part surface that forms an inclined wall that the tool will advance along laterally instead of climbing or descending.
limit line A contour that is used to delimit the areas to machine in an operation.
lower plane One of the two planes normal to the tool axis that confines the area to machine. The operation will only machine between this plane and the upper plane.

## M

machining area An area defined on a part either:
• during an operation as part of the machining geometry ,
• or before an operation, the operation being assigned to a machining area afterwards.

A machining area can be:

• the whole part (for example, in roughing),
• a subset of the faces on the part,
• a subset of faces on the part with a limiting contour.

## P

pencil operations A pencil operation is one where the tool remains tangent in two places to the surface to be machined during the cycle. It is often used to remove crests along the intersection of two surfaces that were left behind by a previous operation.
plunge A movement where the tool plunges deeper into the material, advancing along the (negative) tool axis.
pocket An area on a part surface that represents an internal depression (in Z) relative to the surrounding part surfaces. An internal depression is one that does not extend to the outside edge of the part.
P.P.R. Process Product Resources.

## R

retract The part of a tool path that begins where the tool stops cutting the material.
rework area An area that cannot be machined with a given tool.
reworking An operation which touches up zones that are left completely unmachined by previous operations.
roughing An operation where a part is rough-machined by horizontal planes.
rough stock The block of raw material to be machined to produce a part.

## S

safety distance  A horizontal clearance distance that the tool moves over at the feedrate in order to disengage the tool from cutting between passes.
scallop height The maximum allowable height of the crests of material left uncut after machining.
spindle speed The speed of the spinning tool around its axis.
start point The point where the tool will start cutting in a roughing operation where the surface to cut is accessed from the outside of the part.
stepover distance The width of the overlap between two successive passes.
stop contours The two contours connecting the ends of two guide contours in contour-driven machining (between contours option). The ends of each pass lie on the stop contours.
sweeping operations Sweeping operations machine the whole part and are used for finishing and semi-finishing work.  The tool paths are executed in vertical parallel planes.
sweep roughing An operation where a part is rough-machined by vertical planes.

## U

upper plane One of the two planes normal to the tool axis that confines the area to machine. The operation will only machine between this plane and the lower plane.

## Z

ZLevel machining An operation where the tool progressively follows the part surface at different constant Z values (heights).