Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 339)

Chapter 11
Coordinate Control
11-23
The control has a feature (G68) that can rotate the work coordinate system.
Another feature, external part rotation, rotates all work coordinate systems
by simulating a rotation of the machine coordinate system. Rotating the
coordinate systems can prove to be useful when grinding a part that
contains symmetrical geometries (see Figure 11.14).
Figure 11.14
Part with Symmetrical Geometry
X
Z
This lobe cut
after G68 rotation
of 180
°
This lobe cut
after G68 rotation
of 90
°
This lobe cut
in sub program
This lobe cut
after G68
rotation
of 270
°
Z10.X10.
12017-I
Important: Reciprocation is not permitted on any axis that is rotated. You
cannot:
perform G68 work coordinate rotation and external part rotation on a
reciprocating axis
rotate the work coordinate system of a plane in which one of the axes
assigned to that plane is the reciprocating axis
start reciprocation on one of the axes assigned to the plane in which you
rotated the work coordinate system
11.6
Rotating the Coordinate
Systems