Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 644)

Milling Fixed Cycles
Chapter 26
26-12
4. If a value was programmed for the P parameter, the threading tool
dwells after it reaches the bottom of the hole, and after the spindle has
been commanded to reverse.
The spindle reverses to the clockwise direction.
5. The threading tool retracts at the cutting feedrate to the R point.
6. If a value was programmed for the P parameter, the threading tool
will dwell after it reaches the R point. (Dwells may be ignored if the
system installer has chosen to do so in AMP.)
Then the spindle direction is reversed to counterclockwise.
7. With G98 active, the cutting tool will then accelerate to the rapid
feedrate and retract to the initial point level.
When the single block function is active, the control stops axis motion and
awaits “cycle start” after steps 1, 2 and 7.
If the operator activates a feedhold during steps 3, 4 or 5, axis motion
stops after step 7. Axis motion will also stop during steps 1, 2 and 7.
However, if feedhold is activated during step 7, axis motion will stop
immediately.
Important: Your system installer can enable a tap retract feature for this
cycle through PAL. Tap retract enables you to retract the tapping tool and
resume the cycle, or completely abort the tapping operation. Refer to your
system installers documentation for details.
Use this cycle to cut left-handed threads.
The format for the G74.1 cycle is:
G74.1X__Z__R__F__L__Q__D__S__;
(G74.1): Left-Hand
Solid-Tapping Cycle