
B-63944EN-2/02 PROGRAMMING 5.FUNCTIONS TO SIMPLIFY PROGRAMMING
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5.1.3 Fine Boring Cycle (G76)
The fine boring cycle bores a hole precisely. When the bottom of the
hole has been reached, the spindle stops, and the tool is moved away
from the machined surface of the workpiece and retracted.
Format
G76 X_ Y_ Z_ R_ Q_ 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
Q_ : Shift amount at the bottom of a hole
P_ : Dwell time at the bottom of a hole
F_ : Cutting feedrate
K_ : Number of repeats (if required)
G76 (G98) G76 (G99)
Spindle CW
Initial level
Point R
Point Z
q
P
OSS
Spindle CW
Point R level
Point R
Point Z
q
P
OSS
Explanation
- Operations
When the bottom of the hole has been reached, the spindle is stopped
at the fixed rotation position, and the tool is moved in the direction
opposite to the tool nose and retracted. This ensures that the
machined surface is not damaged and enables precise and efficient
boring to be performed.
- Spindle rotation
Before specifying G76, use a Auxiliary function (M code) to rotate the
spindle.
- Auxiliary function
When the G76 command and an M code are specified in the same
block, the M code is executed at the time of the first positioning
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.
Shift amount q
Spindle orientation
Tool