Siemens SINUMERIK 840D sl Programming Manual page 259

K... :
F...:
Example
Program code
N1608 M3 S10
N1609 G0 G64 Z40 X216
N1610 G33 Z0 K100 SF=R14
N1611 G35 Z-200 K100 F17.045455
N1612 G33 Z-240 K50
N1613 G0 X218
N1614 G0 Z40
N1615 M17
References
Function Manual, Basic Functions; Feedrates (V1), Section "Linear increasing/decreasing
thread lead change with G34 and G35"
Fundamentals
Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
9.11 Thread cutting with increasing or decreasing lead (G34, G35)
Thread lead in Z direction
Thread lead change
If you already know the starting and final lead of a thread, you can
calculate the thread lead change to be programmed according to
the following equation:
The identifiers have the following meanings:
k : Thread lead (thread lead of axis target point coordinate)
a
[mm/rev]
k : Starting thread lead (programmed under I, J, or K) [mm/rev]
G
I : Thread length [mm]
G
Comment
; Spindle on.
; Approach starting point.
; Thread cutting with constant lead
(100 mm/rev)
; Lead decrease: 17.0454 mm/rev2
Lead at end of block: 50mm/rev
; Traverse thread block without jerk.
Motion commands
259