Pilot Drilling (Cycle 21) - HEIDENHAIN TNC 426 B User Manual

PILOT DRILLING (Cycle 21)

When calculating the infeed points, the TNC does not
account for the delta value DR programmed in a TOOL
CALL block.
Process
Same as Cycle 1 Pecking (see "8.2 Drilling Cycles").
Application
Cycle 21 is for PILOT DRILLING of the cutter infeed points. It
accounts for the allowance for side and the allowance for floor as
well as the radius of the rough-out tool. The cutter infeed points
also serve as starting points for roughing.
Plunging depth Q10 (incremental value):
Dimension by which the tool drills in each infeed
(negative sign for negative working direction)
Feed rate for plunging Q11: Traversing speed in mm/
min during drilling
Rough-out tool number Q13: Tool number of the
roughing mill
Example NC blocks:
58 Y L DEF 21.0 PILOT DRILLING
Q10=+5 ;PLUNGING DEPTH
Q11=100 ;FEED RATE FOR PLUNGING
Q13=1 ;ROUGH_OUT TOOL
HEIDENHAIN TNC 426 B, TNC 430
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