HEIDENHAIN TNC 640 (34059x-01) Cycle programming - Manual (Page 352)

352 Cycles: Turning
13.22 L
ONGITUDINAL THREAD (Cy
c
le 831)
Please note while programming:
Program a positioning block to the starting position with
radius compensation R0 before the cycle call.
The TNC uses the set-up clearance Q460 as approach path.
The approach path must be long enough for the feed axes
to be accelerated to the required velocity.
The TNC uses the thread pitch as overrun path. The
overrun path must be long enough to decelerate the feed
axes.
Parameters are available for approach and overrun in
Cycle 832 THREAD LONGITUDINAL EXTENDED.
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).