
B–63832EN/01
13. FUNCTIONS TO SIMPLIFY
PROGRAMMING
NC FUNCTION
119
A program instruction can specify to apply override to a pull–out
operation. (Using this method requires setting an additional parameter.)
To specify pull–out override with a program instruction, specify a
pull–out spindle rotation speed as one of the hole making data items in
a G84 block, using the J address.
This instruction applies override with a value obtained in the following
expression to a pull–out operation.
Spindle rotation speed
(instruction with the J address)
for a return
Spindle rotation speed
(instruction with the S address)
100 = Pull–out override value
If the result of conversion made with the above expression does not fall
in a pull–out override range of from 100% to 2000%, the spindle rotation
instruction is disabled for the pull–out operation; the actual spindle
rotation becomes 100%.
If the J instruction value is greater than the maximum permissible spindle
rotation speed (specified in a parameter) for rigid tapping, the actual
spindle rotation speed is clamped at or near the maximum permissible
spindle rotation speed.
Example)
To make a pull–out operation twice faster than a cut–in operation, use
the following instructions:
@
M29 S1000;
G84 Z–1000. F1000 J2000 ;
@
Appropriate parameter setting enables the conventional feedrate override
select signal and override cancel signal even when rigid tapping is under
way.
In this case, the override value selected by the override select signal can
be used for rigid tapping.
D <G012#0–7> is used as the override select signal.
D <G006#4> is used as the override cancel signal.
D The override value can be changed even when rigid tapping is under
way.
D Using an applicable option enables the second feedrate override
function. This function is applied to the second feedrate that is
determined according to the first feedrate override function.
D The spindle override value is fixed at 100% when rigid tapping is
under way. Because the spindle operation is synchronized with the
operation of the tapping axis, the spindle speed is affected indirectly
by the feedrate override value.
D Enabling the feedrate override select signal disables pull–out override
(regardless of whether it is specified by a program instruction or owing
to a rigid tapping return), causing feedrate override to be applied to the
pull–out operation.
D Program
instruction–based
method
Feedrate override