Siemens SINUMERIK 840D Programming Manual page 173

03.96
04.00
3
3.13 Milling rectangular spigots - CYCLE76 (SW 5.3 and later)
Function
With this cycle you can machine rectangular spigots
in the machining plane. For finishing, a face cutter is
needed. Depth infeed is always performed in the
position reached prior to semi-circular positioning on
the contour.
Sequence of operations
Position reached prior to cycle start:
The starting point is a position in the positive range of
the abscissa with integrated approach semi-circle and
allowance for programmed, abscissa-related blank
dimension.
Sequence of motions for roughing (_VARI=1)
Approach to and exit from contour:
The retraction plane (_RTP) is approached in rapid
traverse so that the tool can be positioned from there on
the starting point in the machining plane. The starting
point is defined as being 0 degrees in relation to the
abscissa.
The tool is fed in at rapid traverse to the safety
clearance (_SDIS) and then traverses to machining
depth at normal feedrate. The tool approaches the
spigot contour along a semi-circular path.
The milling direction can be defined as climb or
opposed milling in relation to the spindle direction.
If the spigot has been circumnavigated once, the tool
lifts off the contour in the plane along a semi-circular
path and is then fed in to the next machining depth.
The contour is then approached again along a semi-
circle and the spigot circumnavigated once. This
process is repeated until the programmed spigot depth
is reached. The tool then approaches the retraction
plane (_RTP) in rapid traverse.
 Siemens AG 2000 All rights reserved.
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide, Cycles (PGZ) - 04.00 Edition
Milling Cycles
Approach to and retraction from the contour in a
semicircle with spindle rotating clockwise and
climb milling
Y
Approach to contour
Retraction from contour
3
X
3-173