HEIDENHAIN CNC Pilot 4290 - Manual (Page 155)

HEIDENHAIN CNC PILOT 4290 143
4.9 Dr
illing Cy
cles
4.9 Drilling cycles
Simple drilling cycle G71
G71 is used for axial and radial bore holes using driven or stationary tools.
The cycle is used for:
■ Individual bore hole without contour description
■ Bore holes with contour definition (individual bore hole or hole
pattern) in the following program sections:
■ FRONT
■ REAR SIDE
■ SURFACE
The type of drill determines when a feed rate reduction begins:
■ Indexable inserts and twist drills with 180° drilling angle:
Reduction at end of hole – 2 * safety clearance
■ Other drills:
Drill end – length of first cut – safety clearance
(length of first cut=drill tip; safety clearance: see machining
parameter 9 ”Drilling” or G47, G147).
Parameters
NS:
Contour block number with geometry of bore hole (G49, G300/
G310-Geo) – no input: Individual bore hole without contour
definition
X, Z: Position, length – end point of axis/radial holes (X diameter
value)
E: Period of dwell in seconds (for chip breaking at end of hole) –
default: 0
V: Feed rate reduction (50%) – default: 0
■ V=0 or 2: Reduction at start
■ V=1 or 3: Reduction at start and at end
■ V=4: Reduction at end
■ V=5: No reduction
Exception with V=0 and V=1: No reduction when boring when
indexable insert drills and twist drills with 180° drilling angle are
used
D: Retraction speed – default: 0
■ D=0: Rapid traverse
■ D=1: Feed rate
K: Retraction plane (radial holes, holes in the YZ plane: diameter) –
default: to starting position or to safety clearance
Cycle run
1 Bore hole without contour definition
Precondition: Tool is located at the safety distance
from the bore hole (”starting position”).
Bore hole with contour definition:
The tool approaches the starting position at rapid
traverse:
■ If K is not programmed: Approach to clearance height
■ If K is programmed: Approach to K, and then to
clearance height.
2 Start drilling bore hole – feed rate reduction
according to ”V.”
3 Drill hole at feed rate.
4 Drill through – feed rate reduction according to ”V.”
5 Retract at rapid traverse or feed rate according to
”D.”
6 Position to which the tool retracts:
■ If K is not programmed: Retraction to the starting
point
■ If K is programmed: Retraction to position K
■ Single hole without contour description:
Program „X or Z“ as alternative.
■ Hole with contour description: Do not
program X, Z.
■ Hole pattern: NS refers to the bore hole
contour (and not the definition of the pattern)).