14. FUNCTIONS TO SIMPLIFY
This cycle is used to bore a hole.
G88 (G98) G88 (G99)
G88 X_ Y_ Z_ R_ P_ F_ K_ ;
X_ Y_: Hole position data
Z_ : The distance from point R to the bottom of the hole
R_ : The distance from the initial level to point R level
P_ : Dwell time at the bottom of a hole
F_ : Cutting feed rate
K_ : Number of repeats
Point R level
After positioning along the X– and Y–axes, rapid traverse is performed
to point R. Boring is performed from point R to point Z. When boring
is completed, a dwell is performed, then the spindle is stopped. The tool
is manually retracted from the bottom of the hole (point Z) to point R.
At point R, the spindle is rotated clockwise, and rapid traverse is
performed to the initial level.
Before specifying G88, use a miscellaneous function (M code) to rotate
When the G88 command and an M code are specified in the same block,
the M code is executed at the time of the first positioning operation. The
system then proceeds to the next drilling operation.
When K is used to specify the number of repeats, the M code is executed
for the first hole only; for the second and subsequent holes, the M code
is not executed.
When a tool length offset (G43, G44, or G49) is specified in the canned
cycle, the offset is applied at the time of positioning to point R.