Siemens SINUMERIK 840D sl Programming Manual page 233

Meaning
INVCW:
INVCCW:
X... Y... Z... :
I... J... K... :
CR=... :
AR=... :
Indirect programming of the end point through specification of an opening angle
NOTICE
With the indirect programming of the end point through specification of an opening angle AR,
the sign of the angle must be taken into account, as a sign change would result in another
involute and therefore another path.
This is demonstrated in the following example:
Fundamentals
Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
9.8 Involute interpolation (INVCW, INVCCW)
Command to travel on an involute in clockwise direction
Command to travel on an involute in counterclockwise
direction
Direct programming of the end point in Cartesian coordinates
Interpolation parameters for the description of the center point
of the basic circle in Cartesian coordinates
Note:
The coordinate specifications refer to the starting point of the
involute.
Radius of the basic circle
Indirect programming of the end point through specification of
an opening angle (angle of rotation)
The origin of the opening angle is the line from the circle
center point to the starting point.
The path of the involute moves away from the
AR > 0:
basic circle.
The path of the involute moves towards the basic
AR < 0:
circle.
For AR < 0, the maximum angle of rotation is
restricted by the fact that the end point must
always be outside the basic circle.
Motion commands
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