Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 614)

Cylindrical Grinding Fixed Cycles
Chapter 17
17-40
Execution of the G89 multi-step plunge with blend cycle performs the
following moves:
1. All Z axis motion that must occur to reach the proper Z endpoint by
the end of the plunge takes place first. This move takes place at the
rapid feedrate.
2. The W axis rapids to the R plane.
3. The W axis plunges to the I level at the feedrate F.
4. The W axis plunges to the Q level at the feedrate E.
5. The W axis plunges to the final depth programmed for X at the
feedrate ,F. If the system installer has configured a micro-feed, it
takes place in this phase. Any micro-feed amount modifies the end
point of the programmed X plunge depth. Micro-feeds are performed
at the ,F feedrate. Be aware that any micro-feed that occurs is not
compensated for on the Z axis. This can cause overcutting (see
page 17-42).
6. If a spark-out is programmed (L word) it is performed after the W
axis has completed its plunge.
7. The Z axis performs the blend. This is programmed with the K
parameter and is performed at the ,E feedrate.
8. The W axis retracts at rapid to the level of the start point.
9. The Z axis returns to the start point at rapid if any micro-feed has
occurred during the W axis plunge.
On some machines and processes, a substantial amount of wheel wear can
occur during the execution of the G89 cycle. This can result in a part that
is not within specifications. Use the micro-feed feature to correct for
wheel wear that can occur between dressing operations.
Wheel wear is compensated for during the fine feed portion of the G89
cycle by adding an additional micro-feed amount to the programmed X
axis plunge depth.
17.11.3
Micro-Feed During the
G89/G89.1 Cycles