HEIDENHAIN TNC 426, User Manual

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HEIDENHAIN TNC 426, TNC 430 285
8.6 SL c
y
cles
8.6 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 enter in Cycle 14
CONTOUR GEOMETRY.
Characteristics of the subprograms
n
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.
n
The TNC ignores feed rates F and miscellaneous functions M.
n
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.
n
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.
n
The subprograms must not contain tool axis coordinates.
n
The working plane is defined in the first coordinate block of the
subprogram. The secondary axes U,V,W are permitted.
Characteristics of the fixed cycles
n
The TNC automatically positions the tool to set-up clearance before
a cycle.
n
Each level of infeed depth is milled without interruptions since the
cutter traverses around islands instead of over them.
n
The radius of “inside corners” can be programmed—the tool keeps
moving to prevent surface blemishes at inside corners (this applies
for the outermost pass in the Rough-out and Side-Finishing cycles).
n
The contour is approached in a tangential arc for side finishing.
n
For floor finishing, the tool again approaches the workpiece in a
tangential arc (for tool axis Z, for example, the arc may be in the Z/X
plane).
n
The contour is machined throughout in either climb or up-cut milling.
The machining data (such as milling depth, finishing allowance and
setup clearance) are entered as CONTOUR DATA in Cycle 20.
Example: Program structure: Machining with SL
cycles
0 BEGIN PGM SL2 MM
...
12 CYCL DEF 14.0 CONTOUR GEOMETRY ...
13 CYCL DEF 20.0 CONTOUR DATA ...
...
16 CYCL DEF 21.0 PILOT DRILLING
17 CYCL CALL
...
18 CYCL DEF 22.0 ROUGH-OUT
19 CYCL CALL
...
22 CYCL DEF 23.0 FLOOR FINISHING ...
23 CYCL CALL
...
26 CYCL DEF 24.0 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 an SL cycle (all
contour subprograms) is limited to 48 kilobytes. The
number of possible contour elements depends on the
type of contour (inside or outside contour) and the number
of subcontours. For example, you can program up to
approx. 256 line blocks.
With MP7420 you can determine where the tool is
positioned at the end of Cycles 21 to 24.