Siemens SINUMERIK 840D Programming Manual page 62

Drilling Cycles and Drilling Patterns 03.96
04.00
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2.1 Drilling cycles
FRF (feedrate factor)
With this parameter you can enter a reduction factor for
the active feedrate which only applies to the approach
to the first drilling depth in the cycle.
VARI (machining mode)
If parameter VARI=0 is set, the drill retracts 1 mm after
reaching each drilling depth for chip breaking. When
VARI=1 (for swarf removal), the drill traverses in each
case to the reference plane moved forward by the
safety clearance.
_AXN (tool axis)
By programming the drilling axis via _AXN, it is possible
to omit the switchover from plane G18 to G17 when the
deep hole drilling cycle is used on lathes.
_MDEP (minimum drilling depth)
You can define a minimum drilling depth for drill stroke
calculations based on degression factor. If the
calculated drilling stroke becomes shorter than the
minimum drilling depth, the remaining depth is
machined in strokes equaling the length of the minimum
drilling depth.
_VRT (variable retraction value for
chip breaking with VARI=0)
You can program the retraction path for chip
breaking in seconds or revolutions.
Value > 0 retraction value
Value = 0 retraction value 1 mm
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SINUMERIK 840D/840Di/810D/FM-NC Programming Guide, Cycles (PGZ) - 04.00 Edition