Checking The Receding Position Of The Moving Knife And The Correcting Method - JUKI DLN-6390 Manual De Instrucciones

IX. THREAD TRIMMER COMPONENTS

1. Checking the receding position of the moving knife and the correcting method

❸
❻
❺
❶
C
B
❽

E
E
I
I
C o r r e c t p o s i t i o n
Moving knife
where moving knife
waiting position
has fully receded
N

❷
❷
❹
J
A
G
F
E
I
H
D

❸
1) Make sure that the power to the sewing machine is
turned OFF.
2) Remove setscrews ❶ , setscrews ❷ and setscrews ❸ .
Then remove hemming binder ❹ , auxiliary throat plate
❺ and throat plate ❻ .
3) Replace the connectors.
• Disconnect connector Z from SC-921.
• Disconnect connector Y and connect connector Y
to the detector of SC-921 to which connector Z is
connected.
• Remove connector X to connect the motor of SC-
921 and the control box.
(Refer to "Wiring diagram of pneumatic and electric
components" on the next page.)
4) Turn ON the power to the sewing machine.
5) Turn the handwheel ❼ by hand in the normal direction
of rotation of the sewing machine A.
(Normal direction of rotation of the sewing machine A
is the counterclockwise direction as observed from the
handwheel side.)
6) When the needle bar goes up and the top end of nee-
dle comes higher than the moving knife, depress the
back part of pedal ❽ in the direction B.
❼
At this time, never depress the front part
of pedal ❽ in the direction C.
(By depressing the front part of the pedal, the thread
trimmer magnet is turned ON and the roller enters the
thread trimmer cam in the sewing machine.)
7) Then turn the handwheel ❼ by hand in the normal
direction of rotation of the sewing machine.
8) Moving knife lever ❾ turns counterclockwise in the
direction D and moving knife  starts receding in the
direction E.
9) When moving knife  has fully receded, the position
where convex F of moving knife  aligns with end
G of the thread pulling plate is the correct position of
moving knife receding position.
The power switch has been turned ON
during the operation of steps 4) through 9).
Never depress the front part of pedal ❽ in
the direction C.
10) At this time, if the receding amount is not proper, be
sure to turn OFF the power switch of the sewing ma-
❾
chine, loosen moving knife tightening screw  , and
tighten moving knife tightening screw  (tightening
torque : 3 to 4 N·m) so that convex F of moving knife
 aligns with end G of the thread pulling plate to ad-
just the moving knife to the correct receding position.
＊
Checking the fully receded position of the moving
knife and the correcting operation have been complet-
ed in steps 1) through 10). Be sure to return the con-
nectors replaced in step 3) and return the components
removed in steps 1) and 2) as well. Then securely
tighten the setscrews.
＊ When installing the throat plate, push it in the direction
of arrow mark N and tighten setscrews ❸ in the state
that stopper  comes in contact with the frame.
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