Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set User Manual

Page 543

Dresser/Wheel Radius Compensation

Chapter 15

15-55

Figure 15.48 shows an example of a typical change in dresser/wheel radius
during jog retract with radius compensation active:

Figure 15.48

Change in Dresser/Wheel Radius During a Jog Retract

Original
dresser/wheel
radius

New
dresser/
wheel
radius

Difference in
dresser/wheel radius

Programmed path

Compensated path

Jog retract moves

Jog retract
return moves

dresser/wheel
radius
changed here

Generated offset block
from difference in
dresser/wheel radius

12139-I

If exiting automatic mode, and if either an MDI motion block is executed
or a manual jog motion is made, the radius compensation feature, if active,
is re-initialized when the next motion block is executed in automatic mode.
The compensation feature compensates the dresser/wheel one radius
perpendicular to the path of the next motion block that is executed in
automatic mode. In effect, the control generates its own entry move for
compensation with the first compensated block being the next block
executed in automatic operation.

Important: The dresser/wheel radius compensation feature is not available
for any motion blocks that are programmed in MDI mode. The
dresser/wheel radius compensation mode can be altered by programming
either G41, G42, or G40, or the dresser/wheel radius can be changed in an
MDI program. However, none of the paths executed in MDI are
compensated. Any changes made to dresser/wheel radius compensation
are not applied until the next block executed in automatic mode.

15.7.5
MDI or Manual Motion
During Dresser/Wheel
Radius Compensation