Troubles In Sewing And Corrective Measures - JUKI DLN-6390 Manuel D'utilisation

*. TROUBLES IN SEWING AND CORRECTIVE MEASURES

Causes of troubles in sewing and corrective measures
Troubles Causes (Items to be checked)
Stitch skipping Check whether clearance between needle
at overlapped and blade point of hook is proper.
section
Check whether kind or size of needle is proper.
Check whether blade point of hook has a
scratch or is blunt.
Check whether relation of position between
needle and needle hole is proper.
Check whether tension of thread take-up
spring is too high.
Check whether stroke of thread take-up is too
small.
Check whether thread tension is too tight.
Check whether needle cooler air pressure is
too high.
Check whether position of hemming binder is
proper.
Check whether cloth is properly rolled.
Check whether needle is bent or needle tip is
blunt.
Check whether needle attaching is proper.
(Direction, insuffi cient insertion, etc.)
Check whether threading is not wrong.
Thread breakage Refer to item "Stitch skipping at overlapped
at overlapped section".
section
Loading at Check whether cloth is properly rolled.
overlapped
section
Check whether installing position of needle
cooler air pipe is proper.
Check whether pressure of presser foot (asm).
is too high.
Corrective measures
Make the clearance between needle and blade point
of hook come near to "0" when thread is caught.
Replace the needle with a proper one.
SCHMETZ UY180GVS is recommended.
(Sewing performance is stabilized when using a
thick one if possible.)
Remove the scratch or replace the hook with a new
one.
Adjust the position of throat plate and presser foot
(asm.) to a proper one.
(The proper position of needle in terms of needle
hole in the throat plate is in the center of both sides
and that in terms of needle hole in the presser foot
(asm.) is slightly to the right side.)
Adjust the tension to a proper one.
(0.2 N is recommended.)
Adjust the position of thread take-up thread guide to
a proper one.
(The position of engraved marker line is the
standard. Moving it to the left increases the stroke
of thread take-up.)
Decrease the thread tension.
Set the air pressure to a proper one (it is better to
set it to rather low).
Adjust the position to a proper one. (Stitch skipping is apt
to occur when needle pierces almost the edge of fold.)
Adjust by handling so that hemming of the bottom
can be properly performed.
(Feed force is not stabilized when cloth becomes
thick due to the failure of rolling.)
Replace the needle with a new one.
Properly attach the needle.
Properly pass the thread.
Refer to item "Stitch skipping at overlapped section".
Adjust by handling so that hemming of the bottom
can be properly performed.
(Feed force is not stabilized when cloth becomes
thick due to the failure of rolling.)
Adjust the position to a proper one.
(If the position is improper, the air pipe interferes
with the presser foot (asm.) and may hinder the lift
of the presser foot (asm.).)
Properly adjust the presser foot (asm.) pressure.
(If the presser spring regulator is excessively
tightened, the lifting amount of the presser foot
(asm.) decreases.)
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