JUKI MEB-3200 Engineer's Manual page 35

Adjustment Procedures
1) Adjusting the initial position
1. Perform the adjustment in the state that the power is turned
OFF and the air is being supplied since the adjustment is
performed in the state that needle thread trimming cylinder is
OFF (extended). Turn looper bracket 4 in the rear (180˚).
2. Insert a tool from the hole on the machine bed side and loosen
clamp screw !4 in vertical moving arm bracket !3 . Move needle
thread trimming vertical moving arm !5 up or down and adjust
clearance A (0.2 mm) of pin !7 of needle thread trimming moving
arm ! 6 . At this time, make sure that clearance C between the
arm and feed base ! 8 is 1 mm or more. After the adjustment,
securely tighten clamp screw !4 .
3. After adjusting the initial position, be sure to adjust the operating
position.
(Caution) If there is interference in clearance C, defective feed
will be caused. If there is no clearance C, check again the
adjustment of needle thread trimming knife.
* In case of the aforementioned step 3), when the machine is
the short thread trimming (J/C) type, needle thread trimming
vertical moving arm can be drawn upward. When the machine
is the long thread trimming (S/R) type, loosen setscrews !2 in
looper thread haul arm 5 to draw the arm. When returning
needle thread trimming vertical moving arm !5 , apply a small
quantity of grease to the shaft section and insert oil wick ! 9 on
vertical moving arm bracket !3 .
2) Adjusting the operating position
1. Operating position changes when the initial position adjustment
is performed.
2. Turn looper bracket 4 in the rear (180˚) in the state that the
power is turned ON (test mode 2) and the air is being supplied.
(State that the needle thread trimming cylinder is ON)
3. Turn ON the needle thread trimming cylinder in the test mode
2. Loosen nut ! 9 and turn adjusting screw @ 0 . Then needle
thread trimming vertical moving arm !5 moves up or down.
Move needle thread trimming moving arm !6 by hand and adjust
clearance B between pin !7 of needle thread trimming moving
arm !6 and needle thread trimming vertical moving arm !5 when
stopper adjusting screw 3 comes in close contact with looper
bracket 4.
4. After the adjustment, securely tighten nut !9 .
5. After the aforementioned adjustment, perform "(24) Adjusting
the looper thread haul amount (long thread trimming/short
thread trimming" and "(25) Adjusting the looper thread haul
driving arm (long thread trimming)".
Results of Improper Adjustment
When clearance A in the initial
position is large :
™ Clearance B does not become
small by the operating position
adjustment and stroke of needle
t h r e a d t r i m m i n g k n i f e i s
insufficient. As a result, thread
trimming failure will be caused.
™ Clearance C between the arm
and feed base !8 interferes and
defective feed will be caused.
When there is no clearance A in the
initial position :
™ When looper bracket 4 turns,
pin ! 7 of needle thread trimming
moving arm ! 6 interferes with
needle thread trimming vertical
moving arm !5 . As a result,
turning failure will be caused.
™ Smilarly, pin !7 comes in contact
with needle thread trimming
moving arm !5 when the bracket
turns and the needle thread
trimming knife moves. As a
result, defective sewing or
sewing components breakage
will be caused.
When clearance B in the operating
position is large :
™ The stroke of needle thread
trimming knife is insufficient. As
a result, thread trimming failure
will be caused.
When there is no clearance B in the
operating position :
™ Excessive force is applied to
needle thread trimming moving
arm ! 6 . As a result, component
breakage will be caused.
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