HEIDENHAIN TNC 640 (34059x-02) Cycle programming - Manual (Page 338)

Cycles: Turning
13.18 RECESSING CONTOUR RADIAL
(Cycle 840, DIN/ISO: G840)
13
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TNC 640 | User's Manual Cycle Programming | 5/2013
Finishing cycle run
1 The TNC positions the tool at rapid traverse to the first slot side.
2 The TNC finishes the side walls of the slot at the defined feed
rate
Q505.
3 The TNC finishes the slot floor at the defined feed rate.
4 The TNC positions the tool back at rapid traverse to the cycle
starting point.
Please note while programming:
The cutting limit defines the contour range to be
machined. The approach and departure paths can
exceed the cutting limits.
The tool position before the cycle call influences the
execution of the cutting limit. The TNC 640 machines
the area to the right or to the left of the cutting
limit, depending on which side the tool has been
positioned before the cycle is called.
Program a positioning block to the starting position
with radius compensation
R0 before the cycle call.
The tool position at cycle call defines the size of the
area to be machined (cycle starting point).
Before calling the cycle you must program the cycle
14 CONTOUR to define the subprogram number.
When you use local
QL Q parameters in a contour
subprogram you must also assign or calculate these
in the contour subprogram.
From the second infeed, the TNC reduces each
further cutting traverse by 0.1 mm. This reduces
lateral pressure on the tool. If the offset width
Q508
was input into the cycle, the TNC reduces the cutting
traverse by this value. After clearance roughing, the
remaining material is removed with a single cut. The
TNC generates an error message if the lateral offset
exceeds 80 % of the effective cutting width (effective
cutting width = cutting width –2*cutting radius).