Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set User Manual

Page 645

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Milling Fixed Cycles

Chapter 26

26-13

Where :

Is :

X

specifies location of the hole.

Z

defines the hole bottom.

R

defines the R point level.

F

represents the thread lead along the drilling axis (Z in this manual). It is
mandatory and modal in any subsequent solid tapping cycle blocks until a new
F-word is programmed.

The control interprets the F-word as the thread lead in inches per revolution or
millimeters per revolution, depending on the inch/metric mode active.

L

defines the number of times the drilling cycle is repeated.

Q

defines the angle at which to orient the spindle before starting the tap. It is modal
in any subsequent solid tapping blocks until a new Q-word is programmed or the
tapping cycle is cancelled by a G80. To retap a hole, a Q-word must have been
programmed when the hole was originally tapped.

D

defines the return spindle speed, but cannot exceed the maximum tapping
spindle speed set in AMP. This will adjust your Z-axis feedrate according to the
thread lead defined in F.

S

defines spindle speed in rpm.

See section 26.3 for a detailed description of these parameters.

Important: When programming and executing a G74.1 solid tapping
cycle, remember:

the feedrate of the tapping phases is derived as

(spindle {RPM}

*

F-lead {IPR}) = IPM

the spindle speed that is active at the start of the cycle determines the
effective Z feedrate

the direction of spindle rotation for tap-in and tap-out phases will be
automatically generated by the control

spindle speed override has no effect on the solid tapping cycle; you can
use feedrate override to adjust the tapping operation

D cannot exceed the maximum tapping spindle speed set in AMP

you cannot select tools via D-word while in solid tapping mode

gear changes are locked out

cycle stop is acknowledged throughout the cycle, but can be disabled by
G63

you can use active reset to abort the cycle after the cycle stop request
has been acknowledged

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