JUKI LK-1910 Engineer's Manual page 23

Adjustment Procedures
1) Determine the position of thread trimmer cam 3, and tighten
screw No. 1 1 of the thread trimmer cam from the upper side
of the sewing machine.
2) Turn the main shaft by 1/4 rotation in the normal direction, and
tighten screw No. 2 2 of the thread trimmer cam from the upper
side of the sewing machine as well.
1) Tilt the sewing machine head.
2) Turn the main shaft and fit thread trimmer roller 2 to approach
run section A of slit 6 of the thread trimmer cam.
3) Loosen nut 3 and loosen thread trimmer link stopper screw 4
to the position where it separates from section B of thread
trimmer connecting bar 5.
4) Pressing cam installing link 1 in the direction of arrow, lightly
fit thread trimmer roller 2 to the thread trimmer cam. (It does
not enter the slit of the cam.)
5) Start tightening thread trimmer link stopper screw 4.
The top end of thread trimmer link stopper screw 4 comes in
contact with section B of thread trimmer connecting bar 5,
and when tightening further, cam installing link 1 turns in the
direction of arrow (f). Then thread trimmer roller 2 which was
lightly fit to the thread trimmer cam enters slit 6 of the thread
trimmer cam.
6) Screw further thread trimmer link stopper screw 4 by half turn
from the point where thread trimmer roller 2 entered slit 6 of
the thread trimmer cam. Then tighten nut 3 to fix it.
At this time, fix thread trimmer link stopper screw 4 so that it
does not turn together with nut 3 and tighten nut 3.
Results of Improper Adjustment
™ Thread trimming failure will
occur.
™ Lock of the sewing machine will
occur at the sewing start or at
the time of thread trimming.
™ Returning the initial position of
the thread trimmer mechanism
is delayed, and poor-tightened
stitch of the first stitch at the
sewing start will occur.
(Caution) When the lock of the
™ Thread trimming failure will
occur.
™ Lock of the sewing machine will
occur at the sewing start or at
the time of thread trimming.
™ Returning the initial position of
the thread trimmer mechanism
is delayed, and poor-tightened
stitch of the first stitch at the
sewing start will occur.
(Caution) When the lock of the
18
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sewing machine has
occured, check the
p l a y o f t h e a x i a l
direction of the main
shaft, position and
timing of the thread
trimmer cam or related
components.
sewing machine has
occured, check the
p l a y o f t h e a x i a l
direction of the main
shaft, position and
timing of the thread
trimmer cam or related
components.