Siemens SINUMERIK 840DE Programming Manual page 147

Example of counterclockwise involute with end point over angle of rotation
Specification of end point via angle of rotation
N10 G1 X10 Y0 F5000
N15 G17
N20 INVCCW CR=5 I-10 J0 AR=360
...
Description
Programming methods
1. Direct programming of the end point with X, Y or X, Y, Z
2. Programming of the angle of rotation between the start and end vectors with AR=angle
Fundamentals
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
(cf. also programming of the arc angle when programming circles). If the angle of rotation
is positive (AR > 0), the path on the involute moves away from the base circle; with a
negative angle of rotation (AR < 0), the path on the involute moves towards the base
circle. The maximum angle of rotation for AR < 0 is restricted by the fact that the end
point must always lie outside the base circle.
Programming Motion Commands
4.13 Involute interpolation (INVCW, INVCCW)
;Approach start position
;Select X/Y plane
;Counterclockwise involute, away from
;base circle (pos. angle setting)
with
;one full rotation
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