Convex Thread (G335, G336) - Siemens Sinumerik 840D sl Programming Manual

Motion commands
10.10 Thread cutting
Program code
N20 G0 G90 X170
N22 POLF[X]=210 LFPOS
N23 POLFMASK(X)
N25 G33 X100 I10 LFON
N30 X135 Z-45 K10
N40 X155 Z-128 K10
N50 X145 Z-168 K10
N55 X210 I10
N60 G0 Z0 LFOF
N70 POLFMASK()
M30
10.10.5

Convex thread (G335, G336)

The G functions G335 and G336 can be used to turn convex threads (= differing to the
cylindrical form). Application is the machining of extremely large components that sag in the
machine because of their self-weight. Paraxial thread would result in the thread being too small
in the middle of the component. This can be compensated with convex threads.
Figure 10-3
Programming
The turning of a convex thread is programmed with G335 or G336:
G335:
G336:
The programming is performed first as for a linear thread by specifying the axial block end
points and the pitch via parameters I, J and K (see "Thread cutting with constant lead (G33,
SF) (Page 214)").
228
Turning a convex thread
Turning of a convex thread on a circular tool path in a clockwise direction
Turning of a convex thread on a circular tool path in a counter-clockwise direction
Comment
; Activate (enable) rapid retraction from axis X.
; Disable lift for all axes.
Programming Manual, 01/2015, 6FC5398-1BP40-5BA2
Fundamentals