HEIDENHAIN iTNC 530 (340 420) ISO programming - Manual (Page 331)

HEIDENHAIN iTNC 530 331
8.8 SL Cy
cles with Cont
our F
or
m
ula
8.8 SL Cycles with Contour Formula
Fundamentals
SL Cycles and the contour formula enable you to form complex
contours by combining subcontours (pockets or islands). 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 complete contour from the selected subcontours,
which you link together through a contour formula.
Properties of the subcontours
n
By default, the TNC assumes that the contour is a pocket. Do not
program a radius compensation. In the contour formula you can
convert a pocket to an island by making it negative.
n The TNC ignores feed rates F and miscellaneous functions M.
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 Although the subprograms can contain coordinates in the spindle
axis, such coordinates are ignored.
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 the 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.
Example: Program structure: Machining with SL
Cycles and contour formula
%CONTOUR G71
...
N50 %:CNT: “MODEL“
N60 G120 Q1= ...
N70 G122 Q10= ...
N80 G79
...
N120 G123 Q11= ...
N130 G79
...
N160 G124 Q9= ...
N170 G79
N180 G00 G40 G90 Z+250 M2
N99999999 %CONTOUR G71
Example: Program structure: Calculation of the
subcontours with contour formula
%MODEL G71
N10 DECLARE CONTOUR QC1 = “ARC1“
N20 DECLARE CONTOUR QC2 = “ARC31XY“
N30 DECLARE CONTOUR QC3 = “TRIANGLE“
N40 DECLARE CONTOUR QC4 = “SQUARE“
N50 QC10 = ( QC1 | QC3 | QC4 ) \ QC2
N99999999 %MODEL G71
%ARC1 G71
N10 I+75 J+50
N20 G11 R+45 H+0 G40
N30 G13 G91 H+360
N99999999 %ARC1 G71
%ARC31XY G71
...
...
The memory capacity for programming an SL cycle (all
contour description programs) is limited to 32 contours.
The number of possible contour elements depends on the
type of contour (inside or outside contour) and the number
of contour descriptions. For example, you can program up
to approx. 1024 line blocks.
The SL Cycles with contour formula presuppose a
structured program layout and enable you to save
frequently used contours in individual programs. Using the
contour formula, you can connect the subcontours to a
complete contour and define whether it applies to a
pocket or island.
In its present form, the “SL Cycles with contour formula”
function requires input from several areas in the TNC’s
user interface. This function is to serve as a basis for
further development.