JUKI MEB-3200 Engineer's Manual page 43

Adjustment Procedures
Remove the knife cover and perform adjustment following the
procedure described below.
(Looper thread clamp)
1. Loosen two setscrews 9.
2. Turn moving knife 3 in the direction of the arrow mark A, move
looper thread clamp fixing plate 6 in the direction of the arrow
mark B and make clearance C between the top end of looper
thread clamp fixing plate 6 and looper thread hauling plate 8
as small as possible (approximately 1 mm). As the standard,
the clearance is 1 mm.
3. After the adjustment, make sure of the clearances described
below.
1) When the marker dot engraved on moving knife 3 is aligned
with the top end of counter knife 4, the top end of looper
thread clamp fixing plate 6 does not interfere with setscrews
!1 in the looper thread hauling plate. (Clearance D)
2) When looper thread clamp opener 1 rotates in the direction
of the arrow mark A and passes over looper thread clamp
!0 , the top end of the lower face of looper thread clamp
opener 1 does not interfere with the bending section of
looper thread clamp !0 .
(Caution) When the setscrews of moving knife 3 are removed
or loosened, the position of moving knife 3 may change.
In this case, perform the aforementioned adjustment of the
looper thread hauling.
(Looper thread clamp openrer )
1. Loosen two setscrews 2.
2. Turn moving knife 3 in the direction of the arrow mark A, align
the corner of the blade section of moving knife 3 with the top
end of counter knife 4.
3. Move looper thread clamp opener 1 in the direction F and
adjust the position so that the bottom face (slant face) comes
off thread clamp pin ! 2 and looper thread clamp 7 comes in
close contact with looper thread clamp fixing plate 6. Then
tighten two setscrews 2 to fix the opener.
(Looper thread hauling)
1. Loosen two setscrews !1 .
2. Turn moving knife 3 in the direction of the arrow mark A, align
the top end of looper thread clamp fixing plate 6 with the
projection in the center of looper thread hauling plate 8 in the
vertical direction. Then tighten two setscrews !1 .
3. Make sure under the test mode that looper thread is inserted
into looper thread clamp 7 and gimp into gimp clamp !0
referring to "8.- (8) Thread trimming check".
1) When both threads are inserted on the side of looper thread
clamp 7, perform fine adjustment so that the projection in
the center of looper thread hauling plate 8 is slightly raised
upward.
2) When both threads are inserted on the side of gimp clamp
!0 , perform fine adjustment so that the projection in the
center of looper thread hauling plate 8 is slightly lowered
downward.
Results of Improper Adjustment
™ If clearance C between the top
end of looper thread clamp fixing
plate 6 and looper thread
hauling plate 8 is excessively
large, inserting amount of looper
thread and gimp is small. As a
result, retaining is not enough
and stitch skipping at the sewing
start or bird's nest will be
caused.
™ If clearance C between the top
end of looper thread clamp fixing
plate 6 and looper thread
hauling plate 8 is excessively
small, the top end of the lower
face of looper thread clamp
opener 1 interferes with the
bending section of looper thread
clamp ! 0 . As a result, parts
breakage will be caused.
™ If clearance C between the top
end of looper thread clamp fixing
plate 6 and looper thread
hauling plate is excessively
small, the top end of looper
thread clamp fixing plate 6
interferes with setscrews !1 in
the looper thread hauling plate.
As a result, parts breakage will
be caused.
™ If the protruding amount of
m o v i n g k n i f e p i n 5 i s
excessively large, the pin
interferes with the presser plate,
right. As a result, malfunction or
parts breakage will be caused.
™ If the height of looper thread
c l a m p f i x i n g p l a t e 6 i s
excessively low, both threads
are inserted on the side of looper
thread clamp 7 and gimp does
not come off at the sewing start.
As a result, thread trimming
failure or thread clamp failure
will occur.
™ If the height of looper thread
c l a m p f i x i n g p l a t e 6 i s
excessively high, both threads
are inserted on the side of gimp
clamp !0 and looper thread
comes off before starting
sewing. As a result, sewing
failure will occur.
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