GSK 988T, User Manual

Page: 133 / 416

Chapter
Ⅱ
G Commands
119
Ⅰ
Programming
Note 7: The tapping cycle temporarily cancels the tool nose radius compensation, and it recovers when
the fixed cycle is cancelled.
Note 8: When the fixed cycle is cancelled in rigid tapping, the used S value is also cleared (its state is the
same that of the specified S0). The specified S for rigid tapping cannot be used in the program
followed by the one for cancelling rigid tapping .
Note 9: Specify S again after cancelling the fixed cycle of rigid tapping.
Note 10: N0.5209#0=0, i.e. drilling axis is selected by the levels in rigid tapping mode”. When G17, G18,
G19 is separately specified in G84, the drilling axes separately correspond to the basic axis X, Z, Y;
when G17, G18, G19 is separately specified in G88, the drilling axes separately correspond to the
basic axis Y, X, Z.
Note 11: In default condition, when G84/88 executes the rigid tapping infeed, the spindle rotates forward;
when the tool retraction is executed, the spindle does CCW. In some special applications, the
spindle rotates reversely, but the spindle does forward when the tool retracts. When the reverse
thread tapping is needed, GSK988T uses the selection signal of the rigid tapping spindle rotation
(RGROD, i.e. G61.2 of PLC address) to realize the reverse thread tapping.
Before G84/G88 is executed, the CNC checks the selection signal’s state of rigid tapping spindle
rotation to confirm the rotation of tapping axis. When RGROD signal is set to 1 and G84/G88
executes the infeed, the spindle rotates forward; when the tool retracts, the spindle rotates
reversely, which is the normal thread tapping; when RGROD signal is set to 1 and the infeed is
done, the spindle rotates reversely, but when the tool retracts, the spindle rotates forward, which
is the reverse thread tapping. After the CNC is turned on, RGROD signal is default to 0.
In the course of G84/G88 rigid tapping, RGROD state is not changed. After G80 is executed,
RGROD state can be reset. Or reset it before G84/G88 is executed.
Adding RGROD signal to the PLC ladder can realize the reverse thread rigid tapping.
Program example:
Suppose that the current system is ISB, and its least input unit is 0.001 mm.
G98
；
feed per minute
M29 S1000
；
switch to the rigid tapping mode, command the
spindle speed 1000. After the block is executed,
the spindle does not rotate.
G0 X50 Z0
；
X and Z position to the stating point
G84 Z-50 P3000 F2000
；
starting point is X50 Z0
，
and the hole position is
the same that the starting point,
；
the hole bottom position is X50 Z-50
，
and the
pause time is 3s
，
；
the thread lead is 2 according to the commanded
F and S value.
；
Q is not commanded and is the standard rigid
tapping cycle.
G80
；
the fixed cycle is cancelled and the motive tool
stops rotation.