Linear Progressive/Degressive Thread Pitch Change (G34, G35) - Siemens SINUMERIK 840DE Programming Manual

Programming Motion Commands

4.16 Linear progressive/degressive thread pitch change (G34, G35)

Note
DITE acts at the end of the thread as an approximate distance. This achieves a smooth
change in the axis movement.
When a block containing command DITS and/or DITE is loaded to the interpolator, the path
programmed in DITS is transferred to SD 42010: THREAD_RAMP_DISP[0] and the path
programmed in DITE to SD 42010 THREAD_RAMP_DISP[1].
The programmed run-in path is handled according to the current setting (inches, metric).
4.16 Linear progressive/degressive thread pitch change (G34, G35)
Function
You can use the functions G34/G35 to produce self-cutting threads.
Both the functions G34 and G35 offer the functionality of G33, but provide the additional
option of programming a pitch change under F.
Programming
G34 X... Y... Z... I... J... K... F...
Or
G34 X... Y... Z... I... J... K... SF=...
Or
G35 X... Y... Z... I... J... K... F...
Or
G35 X... Y... Z... I... J... K... SF=...
Parameters
G34
G35
X Y Z
I
J
K
F
SF=
4-56
Progressive change in thread lead (tapping with linear
pitch increase)
Degressive change in thread lead (tapping with linear
pitch decrease)
End point in Cartesian coordinates
Thread lead in X direction
Thread lead in Y direction
Thread lead in Z direction
Thread lead change (in mm/rev
If you already know the initial and final lead of a
thread, you can calculate the lead change to be programmed
according to the following equation:
2 2
|k - k |
e a
F = ------------- [mm/rev
2*I
G
The identifiers have the following meanings:
Ke: thread lead of axis target point coordinate in
[mm/rev]
Ka: initial thread pitch (progr. under I, J, and K) in
[mm/rev]
I : Thread length in [mm]
G
Starting point offset, only needed for multiple threads
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
2
)
2
]
Fundamentals