HEIDENHAIN TNC 640 (34059x-02) Cycle programming - Manual (Page 380)

Cycles: Turning
13.30 CONTOUR-PARALLEL THREAD
(Cycle 830, DIN/ISO: G830)
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TNC 640 | User's Manual Cycle Programming | 5/2013
Please note while programming:
Program a positioning block to the starting position
with radius compensation
R0 before the cycle call.
The approach path (
Q465) must be long enough
for the feed axes to be accelerated to the required
velocity.
The overrun path (
Q466) must be long enough to
decelerate the feed axes.
Both the approach and overrun take place outside the
defined contour.
When the TNC runs a thread cut, the feed-rate
override knob is disabled. The spindle speed override
knob is active only within a limited range, which is
defined by the machine tool builder (refer to your
machine manual).
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.
With some machine types the turning tool is not
clamped in the milling spindle but in a separate
holder adjacent to the spindle. The turning tool
cannot be rotated through 180° in such cases to
machine internal and external threads with only one
tool for example. If with such a machine you wish
to use an external tool for inside machining, you can
execute machining in the negative diameter range
(-X) and reverse the direction of workpiece rotation.
Note that with pre-positioning in the negative
diameter range, the TNC reverses the effect of the
parameter G471 Thread position (external thread is
then 1 and internal thread 0).
The retraction motion is directly to the starting
position. Always position the tool so that the TNC
can approach the starting point at the end of the
cycle without collisions.