Siemens sinumerik 808d Programming And Operating Manual page 47

Determining F
If you already know the starting and final lead of a thread, you can calculate the thread lead
change F to be programmed according to the following equation:
F
Explanation:
K
e
K Inititial thread lead (under I, K progr.) [mm/U]
a
L thread length in [mm]
G
Programming
G34 Z... K... F...
G35 X... I... F...
G35 Z... X... K... F...
Programming example
Table 1- 1
N10 M3 S40
N20 G0 G54 G90 G64 Z10 X60
N30 G33 Z-100 K5 SF=15
N40 G35 Z-150 K5 F0.16
N50 G0 X80
N60 Z120
N100 M2
Turning Part 2: Programming (Siemens instructions)
Programming and Operating Manual, 05/2012, 6FC5398-5DP10-0BA0
K ² − K ²
e a [
= mm
2 × L
G
Thread lead of the axis end point coordinate [mm/rev]
Cylindrical thread, subsequently with decreasing lead
]
/ U ²
;Cylindrical thread with increasing lead
;Face thread with decreasing lead
;Taper thread with decreasing lead
; Switch on spindle
; Approach starting point
;Thread, constant lead 5mm/rev,
; Activation point at 15 degrees
;Starting pitch 5 mm/rev,
; Pitch decrease 0.16 mm/rev,
; Thread length 50 mm,
;Desired lead at end of block 3 mm/rev
; Retraction in X
Programming principles
1.3 Axis movements
47