HEIDENHAIN SW 548328-05 DIN Programming - Manual (Page 417)

HEIDENHAIN MANUALplus 620, CNC PILOT 620/640
417
4.35 G functions fr
om pr
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ls Simple longitudinal multi-start thread G351
G351 machines a single or multi-start longitudinal thread (internal or
external thread) with variable pitch. The thread starts at the current
tool position and ends at the end point Z.
Internal or external threads:
See algebraic sign of "U."
Number of cutting passes : "I" is used for the first pass. The cutting
depth is reduced with each further pass until "the remaining cutting
depth J" is reached.
Handwheel superposition (provided that your machine is equipped
accordingly): The superposition is limited to the following range:
 X direction:
Depending on the current cutting depth without
exceeding the starting and end points of the thread.
 Z direction:
Maximal 1 thread groove, without exceeding the
starting and end points of the thread.
Parameters
Z Corner point of thread
F Thread pitch
U Thread depth
 U>0: Internal thread
 U<0: External thread
 U= +999 or –999: Thread depth is calculated
I Maximum infeed (no input: I is calculated from the thread pitch
and the thread depth)
A Approach (infeed) angle (default 30°, range: –60° < A < 60°)
 A>0: Infeed on right thread flank
 A<0: Infeed on left thread flank
D Threads per unit (default: 1)
J Remaining cutting depth (default: 1/100 mm)
E Variable pitch (default: 0)
 E>0: Increases the pitch per revolution by E
 E<=: Decreases the pitch per revolution by E
 Cycle stop becomes effective at the end of a thread
cut.
 The feed rate and spindle speed overrides are not
effective during cycle run.
 Handwheel superimpositioning can be activated with a
switch located on the machine operating panel if your
machine is equipped accordingly.
 Feedforward control
is switched off.