Siemens SINUMERIK 840Di sl Programming Manual page 157

N20 INVCCW X32.77 Y32.77 CR=5 I-10 J0
N30 INVCW X10 Y0 CR=5 I-32.77 J-32.77
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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, 11/2006, 6FC5398-1BP10-2BA0
(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.
4.13 Involute interpolation (INVCW, INVCCW)
;E. counterclockwise, end point, radius,
;center point relative to start point
;Start point is end point from N20
;End point is start point from N20,
;radius, center point relative to new
;start point is equal to previous
;center point
;Approach start position
;Select X/Y plane
;Counterclockwise involute, away from base
;circle (pos. angle setting) with
;one full rotation
Motion commands
157