
PROGRAMMING
13. FUNCTIONS TO SIMPLIFY
PROGRAMMING
B–64114EN/01
156
When feed hold is applied during threading in the multiple thread cutting
cycle (G76), the tool quickly retracts in the same way as in chamfering
performed at the end of the thread cutting cycle. The tool goes back to
the start point of the cycle. When cycle start is triggered, the multiple
thread cutting cycle resumes.
See notes in 13.1.2.
NOTE
1 The meanings of the data specified by address P, Q, and R determined by the presence of X
(U) and X (W).
2 The cycle machining is performed by G76 command with X (U) and Z (W) specification.
By using this cycle , one edge cutting is performed and the load on the tool tip is reduced.
Making the cutting depth nd for the first path, and nd
n
for the nth path, cutting amount per one
cycle is held constant.
Four symmetrical patterns are considered corresponding to the sign of each address.
The internal thread cutting is available. In the above figure, the feed rate between C and D is
specified by address F, and in the other path, at rapid traverse. The sign of incremental
dimensions for the above figure is as follows:
U, W : minus (determined by the direction of the tool path AC and CD.)
R : minus (determined by the direction of the tool path AC.)
P : plus (always)
Q : plus (always)
3 Notes on thread cutting are the same as those on G32 thread cutting and G92 thread cutting
cycle.
4 The designation of chamfering is also effective for G92 thread cutting cycle.
5 The tool returns to the cycle start point (cutting depth nd
n
) as soon as the feed hold status is
entered during thread cutting. (nd
n
: cutting depth in nth cut)
6 If start point of thread cutting cycle is close to a workpiece, tool may interfere with the workpiece
during retract cycle because of passing along the retract cycle route described at Note 5.
Therefore start point of thread cutting cycle must be at least k(height of thread) away from the
top of thread.
Normal cycle
Retract cycle
top of
thread
bottom
of thread
start point of thread
cutting cycle
start point of the nth
cycle
1st cycle
2nd cycle
3rd cycle
nth cycle
nd
n
nd
n
k
D Thread cutting cycle
retract