Siemens SINUMERIK 840D Programming Manual page 181

3
12.97
12.98
Function
With the cycle CYCLE72 it is possible to mill along
any contour defined in a subroutine. The cycle
operates with or without cutter radius compensation.
The contour does not need to be closed; internal or
external machining is defined by the position of the
cutter radius compensation (center, on left or right of
contour).
The contour must be programmed in the
direction of milling and must be in the same
plane. In addition, its must consist of at least 2
contour blocks (start and end points) since the
contour subroutine is invoked within the cycle.
Cycle functions:
• Selection of roughing (single-pass parallel to the
contour considering a final machining allowance if
necessary at several depths until reaching the final
machining allowance) and finishing (single-pass of
final contour, if necessary at several depths)
• Flexible approach and retraction to/from the contour
either tangentially or radially (quadrant or semicircle)
• Programmable depth infeed
• Intermediate motions either with rapid traverse or
at feedrate.
The requirement for executing a cycle is an NC SW
4.3. or higher that includes the function "Soft
approach and return".
Sequence of operations
Position reached prior to cycle start:
The starting position can be any position from which
the start of the contour at the retraction plane level
can be reached without collision.
© Siemens AG, 2002. All rights reserved
SINUMERIK 840D/840Di/810D Programming Guide Cycles (PGZ) – 11.02 Edition
3.12 Path milling – CYCLE72
3
Milling Cycles
3-181