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Trouble
Cause (1)
Cause (2)
Check and corrective measures
16. Faulty thread trimming
(The needle thread is not
trimmed.)
(The bobbin thread is not
trimmed.)
16-1) Wear of the cutting portion
of a thread trimming knife or
loop spreading knife
It is replaced by a new knife.
16-2) The thread loop formation is
unstable.
2-A)
The high-count filament type
thread is being used.
The thread trimming cam timing is corrected
by changing a maker dot from a green one to a
red one.
17. Faulty thread trimming
(The needle thread is trimmed
short.)
17-1) The strength of the thread is
weak.
1-A)
The high-count filament type
thread or cotton thread is being
used.
The rotating speed for trimming thread is low-
ered.
The edge lines other than cutting portion of a
thread trimming knife are buffed to the extent
of R0.5.
