Siemens SINUMERIK 840D sl Programming Manual page 235

parameters in the center point programming must be programmed with IR=..., JR=... and
KR=....
IR=...:
JR=...:
KR=...:
Note
IR, JR and KR are the default values of the interpolation parameter names for a convex thread
that can be set via machine data (MD10651 $MN_IPO_PARAM_THREAD_NAME_TAB).
Differences to the default values must be taken from the specifications of the machine
manufacturer.
Optionally, a starting point offset SF can also be specified (see "Thread cutting with constant
lead (G33, SF) (Page 221)").
Syntax
The syntax for the programming of a convex thread therefore has the following general form:
G335/G336 <axis target point coordinate(s)> <pitch> <arc> [<starting
point offset>]
Examples
Example 1: Convex thread in the clockwise direction with end and center point programming
Program code
N5 G0 G18 X50 Z50
N10 G335 Z100 K=3.5 KR=25 IR=-20 SF=90
Figure 2-7
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
Cartesian coordinate for the circle center point in the X direction
Cartesian coordinate for the circle center point in the Y direction
Cartesian coordinate for the circle center point in the Z direction
Convex thread in the clockwise direction with end and center point programming
Fundamentals
2.9 Motion commands
Comment
; Approach starting point.
; Turn convex thread in the clock-
wise direction.
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