JUKI LH-3500 Series, Инструкция по эксплуатации, Страница: 49 / 50

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9. TROUBLES AND CORRECTIVE MEASURES
TROUBLES CAUSES CORRECTIVE MEASURES
. Thread breakage
(Thread s
untwsted or
scraped.)
(Needle thread 2 to
3 cm s left on the
wrong sde of the
fabrc.)
1
There s a sharp edge or burr on
the thread path, needle pont,
hook blade pont or bobbn case
restng groove on the throat plate.
2
Needle thread tenson s too hgh.
3
Bobbn case openng lever
provdes an excessve clearance
at the bobbn case.
4
Hook blade pont hts the needle.
5
Hook s not lubrcated properly.
6
Needle thread tenson s too low.
7
Thread take-up sprng s too tght
and ts stroke s too small.
8
Needle-to-hook tmng s wrong.
9
Thread untwsts.
!0
Unform thread loops cannot be
formed when makng chan-off
thread.
™
Remove sharp edge or burr using a fine
sandpaper. Polsh the surface of the
bobbn case restng groove on the throat
plate using a buffing wheel.
™
Adjust the needle thread tenson.
™
Reduce the clearance.
(Refer to "6-4. Adjusting the inner hook
guide", P. 30 .)
™
Refer to "4-15. Needle-to-hook
relation", P. 21 .
™
Increase the amount of ol suppled to the
hook accordng to "4-4. Adjusting the
amount of oil in the hook", P. 10 .
™
Adjust the needle thread tenson.
™
Reduce the tenson of the sprng and
ncrease the stroke.
™
Refer to "4-15. Needle-to-hook
relation", P. 21 .
™
Wnd the thread on the needle.
™
Use the thread gude equpped wth felt
pad.
2. Sttch skppng
1
Clearance between the needle
and the hook blade pont s too
great.
2
Needle-to-hook relaton s wrong.
3
Pressng force of the presser foot
s not enough.
4
Needle bar heght s wrong.
5
Needles are a lttle too thn.
6
Synthetc thread or thn thread s
used.
™
Refer to "4-15. Needle-to-hook
relation", P. 21 .
™
Refer to "4-15. Needle-to-hook
relation", P. 21 .
™
Tghten the presser sprng regulator.
™
Refer to "4-15. Needle-to-hook
relation", P. 21 .
™
Replace the needle by thcker ones.
™
Wnd the thread on the needle.
3. Loose sttch
1
Bobbn thread does not pass
through the forked end of the
tenson sprng on the bobbn case.
2
Thread path has rough surface.
3
Bobbn does not spn smoothly.
4
Bobbn case openng lever
provdes too much clearance at
the bobbn.
5
Bobbn thread tenson s too low.
6
Bobbn s wound too tghtly.
™
Thread the bobbn case correctly.
™
Remove rough surface using a fine
sandpaper or polsh the surface usng a
buffing wheel.
™
Replace the bobbn or the hook.
™
Refer to "6-4. Adjusting the inner hook
guide", P. 30 .
™
Adjust the bobbn thread tenson.
™
Adjust the tenson components on the
bobbn wnder.