HEIDENHAIN TNC 320 User Manual page 224

9.2 SL Cycles with Simple Contour
Formula
Fundamentals
SL cycles and the simple contour formula enable you to form contours
by combining up to 9 subcontours (pockets or islands) in a simple
manner. You define the individual subcontours (geometry data) as
separate programs. In this way, any subcontour can be used any
number of times. The TNC calculates the contour from the selected
subcontours.
The memory capacity for programming an SL cycle (all
contour description programs) is limited to 128 contours.
The number of possible contour elements depends on the
type of contour (inside or outside contour) and the number
of contour descriptions. You can program up to 16384
elements.
Properties of the subcontours
Do not program a radius compensation.
The TNC ignores feed rates F and miscellaneous functions M.
Coordinate transformations are allowed. If they are programmed
within the subcontour they are also effective in the following
subprograms, but they need not be reset after the cycle call.
Although the subprograms can contain coordinates in the spindle
axis, such coordinates are ignored.
The working plane is defined in the first coordinate block of the
subprogram.
Characteristics of the fixed cycles
The TNC automatically positions the tool to the set-up clearance
before a cycle.
Each level of infeed depth is milled without interruptions since the
cutter traverses around islands instead of over them.
The radius of "inside corners" can be programmed—the tool keeps
moving to prevent surface blemishes at inside corners (this applies
to the outermost pass in the Rough-out and Side Finishing cycles).
The contour is approached on a tangential arc for side finishing.
For floor finishing, the tool again approaches the workpiece on a
tangential arc (for spindle axis Z, for example, the arc may be in the
Z/X plane).
The contour is machined throughout in either climb or up-cut milling.
The machining data (such as milling depth, finishing allowance and
set-up clearance) are entered as CONTOUR DATA in Cycle 20.
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Example: Program structure: Machining with SL
cycles and complex contour formula
0 BEGIN PGM CONTDEF MM
...
5 CONTOUR DEF
P1= "POCK1.H"
I2 = "ISLE2.H" DEPTH5
I3 "ISLE3.H" DEPTH7.5
6 CYCL DEF 20 CONTOUR DATA...
8 CYCL DEF 22 ROUGH-OUT...
9 CYCL CALL
...
12 CYCL DEF 23 FLOOR FINISHING...
13 CYCL CALL
...
16 CYCL DEF 24 SIDE FINISHING...
17 CYCL CALL
63 L Z+250 R0 FMAX M2
64 END PGM CONTDEF MM
Fixed Cycles: Contour Pocket with Contour Formula