HEIDENHAIN TNC 640 (34059x-01) Cycle programming - Manual (Page 170)

170 Fixed Cycles: Contour Pocket
7.
1 SL Cy
cles
7.1 SL Cycles
Fundamentals
SL cycles enable you to form complex contours by combining up to 12
subcontours (pockets or islands). You define the individual
subcontours in subprograms. The TNC calculates the total contour
from the subcontours (subprogram numbers) that you enter in Cycle
14 CONTOUR GEOMETRY.
Characteristics of the subprograms
„ 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.
„ The TNC recognizes a pocket if the tool path lies inside the contour,
for example if you machine the contour clockwise with radius
compensation RR.
„ The TNC recognizes an island if the tool path lies outside the
contour, for example if you machine the contour clockwise with
radius compensation RL.
„ The subprograms must not contain spindle axis coordinates.
„ Always program both axes in the first block of the subprogram
„ If you use Q parameters, then only perform the calculations and
assignments within the affected contour subprograms.
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.
Example: Program structure: Machining with SL
cycles
0 BEGIN PGM SL2 MM
...
12 CYCL DEF 14 CONTOUR GEOMETRY ...
13 CYCL DEF 20 CONTOUR DATA ...
...
16 CYCL DEF 21 PILOT DRILLING ...
17 CYCL CALL
...
18 CYCL DEF 22 ROUGH OUT ...
19 CYCL CALL
...
22 CYCLE DEF 23 FLOOR FINISHING ...
23 CYCL CALL
...
26 CYCL DEF 24 SIDE FINISHING ...
27 CYCL CALL
...
50 L Z+250 R0 FMAX M2
51 LBL 1
...
55 LBL 0
56 LBL 2
...
60 LBL 0
...
99 END PGM SL2 MM
The memory capacity for programming the cycle is limited.
You can program up to 16384 contour elements in one
cycle.
SL cycles conduct comprehensive and complex internal
calculations as well as the resulting machining operations.
For safety reasons, always run a graphical program test
before machining! This is a simple way of finding out
whether the TNC-calculated program will provide the
desired results.