HEIDENHAIN CNC Pilot 4290 V7.1 - Manual (Page 252)

252
4.23 Dr
illing Cy
cles
The cycle is used for:
„ Single hole without contour description
„ Hole with contour description (single hole or hole pattern)
“1st drilling depth P” is used for the first pass. MANUALplus then
automatically reduces the drilling depth with each subsequent pass by
the reduction value I, however, without falling below the minimum
drilling depth J. After each pass, the tool is retracted either by
retraction distance B or to the starting point of the hole.
Feed rate reduction:
„ Indexable insert drill and twist drill with 180° drilling angle
„ Beginning of hole: No feed rate reduction (even with V=0 or V=1)
„ End of hole: Reduction as of hole end point – 2*safety clearance
„ Other drills
„ Beginning of hole: Feed rate reduction as programmed in V
„ End of hole: Reduction as of hole end point—length of first cut—
safety clearance
„ Length of first cut = tool tip
„ Safety clearance: see machining parameter 9 “Drilling” or G47,
G147).
„ 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 hole contour, and not the
definition of the pattern.
„ A “feed rate reduction at end” goes into effect only at
the last drilling stage
Cycle run
1 „ Hole without contour definition: Tool is located at the
starting point (safety distance from the bore hole).
„ Hole with contour description: Tool moves at rapid traverse
to the starting point:
„ K not programmed: Moves up to the safety clearance
„ K programmed: Moves to the position K and then to the
safety clearance
2 Spot drilling. Feed rate reduction depending on V
3 Drill hole in several passes.
4 Through drilling. Feed rate reduction depending on V
5 Retract depending on D at rapid traverse or feed rate.
6 Retraction position depends on K:
„ K not programmed: Retraction to the starting point
„ K programmed: Retraction to the position K