Siemens SINUMERIK 840D Programming Manual page 175

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12.97
12.98
The first path to be milled is always selected so that
the infeed width is exactly _MIDA, and thus no width
exceeds the maximum possible value. The tool
center point thus does not always travel exactly to
the edge (only if _MIDA = mill radius). The
dimension by which the tool traverses outside the
edge always equals
cutter diameter - _MIDA,
even when only 1 surface cut is performed, i.e.
surface width + overrun less than _MIDA. The other
paths for width infeed are calculated internally so as
to produce a uniform path width (<=_MIDA).
• Motion sequence when finishing (VARI=X2):
When finishing, the surface is once milled in the
plane. The final machining allowance for roughing
must also be selected so that the remaining
depth can be machined in one pass with the
finishing tool.
After each surface milling pass in the plane, the
tool retracts completely. The retraction travel is
programmed by the parameter _FDP.
• Machining in one direction stops at the final
machining allowance + safety distance and the next
starting point is reached at rapid traverse.
Roughing in one directions stops when reaching the
calculated infeed depth + safety distance. The
infeed depth is performed towards the same point
as for roughing.
After finishing has been completed, the tool retracts
from the last position reached to the retraction plane
_RTP.
© Siemens AG, 2002. All rights reserved
SINUMERIK 840D/840Di/810D Programming Guide Cycles (PGZ) – 11.02 Edition
3.11 Face milling – CYCLE71
Y
Milling during finishing in one direction
(type of machining 22)
3
Milling Cycles
_FDP
_FDP
X
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