Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 641)

Drilling Cycles
Chapter 26
26-15
6. After the drilling tool retracts an amount d, it then resumes drilling at
the cutting feedrate to a depth d + Q.
This retraction and extension continues until the drilling tool reaches
the depth of the hole as programmed with the Z-word in the drilling
cycle block.
7. The drilling tool then retracts 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 and
awaits “cycle start” after steps 1, 2 and 7.
Use this cycle to cut right-handed threads. The format for the G84 cycle
is:
G84X__Z__R__P__F__L__;
Where : Is :
X specifies location of the hole.
Z defines the hole bottom.
R defines the R point level.
P defines the dwell period at hole bottom.
F defines the cutting feedrate and represents the thread lead along the drilling axis
(Z in this manual). It is mandatory when cutting any threads. The control
interprets the F-word as the number of threads per inch or millimeter.
L defines the number of times the drilling cycle is repeated.
See section 27.3 for a detailed description of these parameters.
Important: When programming and executing a G84 tapping cycle,
remember:
the programmer or operator must start spindle or live tool rotation
override usage - the control ignores the feedrate override switch and
clamps override at 100 percent
during tapping, the feedrate override switch and the feedhold feature are
both disabled; cycle stop is not acknowledged until the end of the return
operation
(G84): Right-Hand Tapping
Cycle