JUKI DLN-6390 Engineer's Manual page 46

Troubles
From the previous page
1-5) Thread path components.
1-6) Flopping of cloth.
1-7) Needle position is improper.
1-8) Binder components.
1-9) Setting of needle cooler is
2. Stitch gathering at 2-1) Presser components.
overlapped section
2-2) Binder components.
3. Thread breakage 3-1) Hook components.
To the next page
Cause (1)
improper.
Cause (2)
5)-A Threading is wrong.
6)-A Presser is rising.
6)-B Angle of the presser is
wrong.
6)-C Pressure of the presser is
low.
6)-D Presser foot comes in
contact with the hemming
binder.
7)-A Lateral position of needle
and the needle hole of
throat plate is wrong.
7)-B Lateral position of needle
and the needle hole of
presser foot is wrong.
8)-A E d g e o f f o l d i n g o f
hemming is sewn.
8)-B Sewing is performed in
t h e c o n d i t i o n t h a t
hemming is rolled in more
than three fold.
8)-C Sewing quality of the
p r e v i o u s p r o c e s s i s
i n f e r i o r ( e s p e c i a l l y
lapping seam).
9)-A Air pressure of needle
cooler is too high.
1)-A Pressure of the presser is
too high.
1)-B Position of cooling pipe is
w r o n g a n d t h e p i p e
comes in contact with the
presser foot.
2)-A Sewing is performed in
t h e c o n d i t i o n t h a t
hemming is rolled in more
than three fold.
2)-B Sewing quality of the
p r e v i o u s p r o c e s s i s
i n f e r i o r ( e s p e c i a l l y
lapping seam).
1)-A Blunt or worn-out of the
blade point of hook
1)-B Clearance at the blade
point of hook is improper.
1)-C Hook timing is improper.
1)-D No needle guard
42
Corrective measures
Check the threading according to the
Instruction Manual.
Check the presser lifting base according
to the Instruction Manual.
Correct the angle of presser according to
4-(19).
Adjust the pressure of the presser foot
according to the Instruction Manual.
Correct the position of binder base on the
Instruction Manual. When the presser foot
comes in contact with the hemming binder,
the presser foot rises or the motion is
hindered.
Correct the lateral position of needle.
Alignment of the center of needle hole in
throat plate with the center of needle is
the aim.
Loosen the presser bar bracket and
correct the lateral position of presser. It is
the aim that the center of the needle in
terms of the center of needle hole in the
presser foot is slightly located to the right
side.
Correct the lateral position of hemming
binder to the proper position.
Adjust by handling so that correct
hemming is performed. (When cloth
becomes thicker than necessary due to
inferior rolling, stitch skipping is apt to
occur.)
Check the rolled condition of the previous
process.
(When cloth becomes thicker than
necessary due to inferior rolling of the
previous process, stitch skipping is apt to
occur.)
Set the air pressure to the proper one
(lower is better if possible).
When the air pressure is excessively high,
needle thread becomes unstable and
inferior products are apt to occur.)
Adjust the pressure of presser foot
according to the Instruction Manual.
When excessively tightening the pressure
adjustment dial, the lifting angle of the
presser is limited.
Correct the position of needle cooler pipe
according to the Instruction Manual.
When the installing position of pipe is
improper, pipe comes in contact with
presser foot when the presser rides on the
overlapped section and lift of the presser
may be hindered.
Adjust by handling so that correct
hemming is performed. (When cloth
becomes thicker than necessary due to
inferior rolling, stitch gathering is apt to
occur.), stitch gathering is apt to occur.)
Check the rolled condition of the previous
process
(When cloth becomes thicker than
necessary due to inferior rolling of the
previous process, stitch gathering is apt
to occur.)
Correct the blade point of hook or replace
the hook.
Make small the clearance between needle
and the blade point (near to "0").
Adjust the timing according to 4-(2).
Perform adjustment described in the
Instruction Manual as the aim and in
accordance with the conditions of cloth and
thread, perform fine adjustment according
to 4-(21).
Especially, in case of thick materials, use
the designated hook with needle guard.