HEIDENHAIN SW 54843x-02 DIN Programming - Manual (Page 297)

HEIDENHAIN MANUALplus 620, CNC PILOT 640 297
4.1
9
Thr
ead cy
cles
Thread single path G33
G33 conducts a single thread cut. The direction of the single thread
path is as desired (longitudinal, tapered or transverse threads; internal
or external threads). You can make successive threads by
programming G33 several times in succession.
Position the tool in front of the thread by the run-in length B if the slide
must accelerate to the feed rate. And remember the run-out length P
before the end point of thread if the slide has to be decelerated.
Run-in length B: The slide requires a run-in distance at the start of
thread in order to accelerate to the programmed feed rate before
starting the actual thread.
Default: cfgAxisProperties/SafetyDist
Run-out length P: The slide needs an overtravel at the end of the
thread to decelerate again. Remember that the paraxial line P needs
overtravel even with an oblique thread run-out
 P=0: Start of a successive thread
 P>0: End of a successive thread
Starting angle C: At the end of the "run-in path B" the spindle is at the
"starting angle C" position.
Example: G33
. . .
N1 T5 G97 S1100 G95 F0.5 M3
N2 G0 X101.84 Z5
N3 G33 X120 Z-80 F1.5 P0 [thread single
path]
N4 G33 X140 Z-122.5 F1.5
N5 G0 X144
. . .
Parameters
X
End point of thread (diameter)
Z End point of thread
F Thread pitch
B Slop. length (run-in length; length of the acceleration path)
P Overflow length (run-out length; length of the deceleration
path)
C Starting angle (thread start is defined with respect to
rotationally nonsymmetrical contour elements)—(default: 0)
H Reference direction for thread pitch (default: 0)
 0: Feed rate on the Z axis (for longitudinal and taper threads
up to a max. angle of +45°/–45° to the Z axis)
 1: Feed rate on the X axis (for transverse and taper threads
up to a max. angle of +45°/–45° to the X axis)
 3: Contouring feed rate
E Variable pitch (default: 0)—(no effect at present)
I Retraction distance in X—retraction path for cycle stop in the
thread, incremental value
K Retraction distance in Z—retraction path for cycle stop in the
thread, incremental value
 Cycle stop—the control retracts the tool from the thread
groove and then stops all tool movements. (Lift-off
distance: OEM configuration parameter:
cfgGlobalPrperties-threadliftoff)
 Feed rate override is not effective
 Create thread with G95 (feed rate per revolution)