Siemens SINUMERIK 840Di sl Programming Manual page 156

Motion commands
4.13 Involute interpolation (INVCW, INVCCW)
Parameters
INVCW
INVCCW
X Y Z
I J K
CR=
AR=
Supplementary condition
Both the start point and the end point must be outside the area of the base circle of the
involute (circle with radius CR around the center point determined by I, J and K). If this
condition is not fulfilled, an alarm is generated and the program run aborted.
Note
For more information about machine data and supplementary conditions that are relevant to
involute interpolation, please see References: /FB1/, A2 section "Settings for involute
interpolation".
Example of counterclockwise involute and back as clockwise involute
Counterclockwise involute according to programming method 1 from start to end point and
back again (clockwise involute)
N10 G1 X10 Y0 F5000
N15 G17
156
Travel on an involute in clockwise direction
Travel on an involute path in counterclockwise direction
End point in Cartesian coordinates
Center point of base circle in Cartesian coordinates
Radius of base circle
Opening angle (angle of rotation)
;Approach start position
;Select X/Y plane
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
Fundamentals