G84.1): left-hand tapping cycle – Rockwell Automation 8520 9/Series CNC Lathe User Manual

Page 643

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Drilling Cycles

Chapter 26

26-17

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 or live tool reverses to the counterclockwise 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

dwells after it reaches the R point. Dwells may be ignored if the

system installer has chosen to do so in AMP.

The spindle or live tool direction is reversed to clockwise.

7.

With G98 active, the cutting tool then accelerates to the rapid feedrate

and retracts to the initial point level.

When the single block function is active, the control stops axis motion

after steps 1, 2 and 6.

If the operator activates a feedhold during steps 3, 4 or 5, axis motion

stops after step 7. Axis motion also stops during steps 1, 2, and 7.

However, if the operator activates a feedhold during step 7, axis motion

stops 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 G84.1 cycle is:

G84.1X__Z__R__P__F__L__;

Where :

Is :

X

specifies the location of the hole position in the selected plane.

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.

(G84.1): Left-Hand Tapping

Cycle

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