Operation Manual

HEIDENHAIN CNC PILOT 4290 225
4.20 Contour-Based Turning Cycles
Recess turning cycle G869
G869 machines the contouring area axially/radially from NS to NE as
defined by NS, NE. The workpiece is machined by alternate recessing
and roughing movements. The machining process requires a
minimum of retraction and infeed movements. The contour to be
machined can contain various valleys. If required, the area to be
machined is divided into several sections.
Z
K
X
Z
B
0,1mm
A
I
Ø
X
Ø
Parameters
NS Start block number
 Beginning of the contour section, or
 Reference to a G22/G23-Geo recess
NE End block number (end of contour section)
 NE not programmed: The contour element NS is machined
in the direction of contour definition.
 NS=NE programmed: The contour element NS is machined
opposite to the direction of contour definition.
 NE is inapplicable if the contour is defined by G22/G23-Geo
P Maximum infeed
R Turning depth compensation for finishing (default: 0)
I Oversize in X direction (diameter value) – (default: 0)
K Oversize in Z direction (default: 0)
X Cutting limit (diameter value)—(default: no cutting limit)
Z Cutting limit (default: no cutting limit)
A Approach angle (default: opposite to recessing direction)
W Departure angle (default: opposite to recessing direction)
Q Action (default: 0)
 Q=0: Roughing and finishing
 Q=1: Only roughing
 Q=2: Only finishing
U Unidirectional turning (default: 0)
 U=0: The roughing passes are bidirectional.
 U=1: The roughing passes are unidirectional (from NS to
NE)
H Type of retraction at cycle end (default: 0)
 H=0: Return to starting point (axial recess: first direction Z,
then X; radial recess: first X direction, then Z)
 H=1: Positions in front of the finished contour
 H=2: Retracts to safety clearance and stops