Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 598)

Cylindrical Grinding Fixed Cycles
Chapter 17
17-24
Figure 17.6
G85 Multi-pass Diameter Grinding Motions
Retract
K
Spark-out
passes
Z
X
Q
START
Part
12056-I
Programming a G85 causes the control to execute a multi-pass diameter
grinding cycle. This cycle is typically used to grind the diameter of a part
in a situation where a shifting of the grinding wheel position is necessary
to cover several different surfaces that are to be ground at the same
diameter. Axis 1, the Z axis in our case, is the dither axis and axis 2, the X
axis, is the plunge axis. The G85.1 cycle is identical but begins with a
pre-dress operation prior to the grind.
The G85 cycle differs from the G83 cycle in several ways. First, the Z axis
dither differs from reciprocation in that it is made up motions of that are
centered about the Z axis coordinate and are made only during the plunge
move. Second, the plunge motion is a continuous move to the plunge
depth (X) instead of a series of plunge pick moves as used with the G83
cycle.