JUKI MEB-3200 Engineer's Manual page 31

Adjustment Procedures
™ J and C type (short thread trimming)
1. The clearance between needle thread trimming knife J 2 and
the needle is approximately 1 mm. Loosen setscrew 1 and
move needle thread triming knife J 2 to adjust the clearance.
2. The overlapping amount between looper thread presser 3 and
the top end section of throat plate 4 is 0 to 0.2 mm, and adjust
so that no clearance is provided between them.
Loosen adjustment nut 5 and adjust the position of the top
end of looper thread presser 3 with adjustment screw 6.
3. The height of needle thread trimming knife J 2 is determined
by the adjustment value of looper thread presser 3. After the
adjustment of step 4) below, confirm that clearance A between
the looper thread presser and throat plate 4 and that B between
the looper thread presser and right spreader 7 are securely
obtained.
4. The height of looper thread presser 3 is the position where
the top end is lowered by 0 to 0.5 mm from the flat face of
throat plate 4. Loosen setscrew 8 and move needle thread
trimming knife adjustment base 9 up or down to adjust the
height of the top end of looper thread presser 3.
(Caution) When needle thread trimming knife J 2 comes in
contact with throat plate 4 and spreader, right 7, breakage
of components will be caused. Make sure of the clearances
"A" and "B".
5. The initial position of needle thread trimming knife J 2 and
looper thread presser 3 is the position where the left corner of
the top end of looper thread presser 3 is aligned with the right
corner of the slot of throat plate 4. Loosen adjustment nut !1
and adjust the initial position with adjustment screw !2 .
6. The operating position of needle thread trimming knife J 2 is
the position where needle thread trimming knife J 2 comes
out by 1.2 to 1.5 mm from throat plate 4 when needle thread
trimming actuating arm !0 is moved counterclockwise and
stopper B !3 of the needle thread trimming actuating arm comes
in confact with the top surface of the looper bracket.
When the adjustment is necessary, remove needle thread
trimming adjusting base 9 once with setscrew 8 and adjust
the protruding amount of stopper B of the needle thread
trimming actuating arm !3 to 1 to 1.2 mm.
(Caution) Stopper B !3 of the needle thread trimming actuating
arm is a double thread screw.
Results of Improper Adjustment
27
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