Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set User Manual
Page 651
Milling Fixed Cycles
Chapter 26
26-19
Figure 26.8
G81: Drilling Cycle without Dwell
Hole bottom
R point level
initial point
level
Cutting feed
Rapid feed
R
Z
1
2
3
4
In the G81 drilling cycle, the control moves the axes in the following
manner:
1.
The tool rapids to the initial point level above the hole location.
2.
The drilling tool then rapids to the R point level, slows to the
programmed cutting feedrate and begins the drilling operation.
3.
The drilling tool continues to drill at the programmed feedrate until it
reaches the depth of the hole as programmed with the Z--word.
4.
The control retracts the drilling tool at a rapid feedrate to the initial
point level as determined by G98.
When the single block function is active, the control stops axis motion
after steps 1, 2 and 4.