Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 358)

Coordinate Control
Chapter 13
13-6
Figure 13.4
Results of Example 13.3
Center of
rotation after G52
Initial center
of rotation
Cut during
second
execution
of sub-
program
Cut during
first
execution
of sub-
program
Cut during
fourth
execution
of sub-
program
Cut during
third
execution
of sub-
program
+
+
(55, 60)
(55, 60)
(70, 45)
(65, 15) (45, 15)
(40, 45)
The external part rotation feature simulates a rotation of the machine
coordinate system. Since all work coordinate systems are referenced from
the machine coordinate system, rotating it would effectively rotate all work
coordinate systems. However, software overtravels, programmable zone
limits, homing, and positioning in the machine coordinate system are not
affected.
When external part rotation is activated all work coordinate systems are
rotated together by a specified amount, about a specified point.
External Part Rotation can be executed before or after rotation of the work
coordinate system using the G68 command (as described in section
13.1.1). If a G68 is programmed to rotate the current work coordinate
system, an additional rotation of coordinates will result as shown in
Figure 13.5.
13.1.2
External Part Rotation