JUKI LH-3528 User Manual

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9. TROUBLES AND CORRECTIVE MEASURES
CORRECTIVE MEASURES
™
Remove sharp edge or burr using a fine
sandpaper. Polish the surface of the
bobbin case resting groove on the throat
plate using a bufng wheel.
™
Adjust the needle thread tension.
™
Reduce the clearance. (Refer to "6-4.
Adjusting the inner hook guide".)
™
Refer to "4-14. Needle-to-hook relation".
™
Increase the amount of oil supplied to
the hook according to "4-3. Adjusting the
amount of oil in the hook".
™
Adjust the needle thread tension.
™
Reduce the tension of the spring and
increase the stroke.
™
Refer to "4-14. Needle-to-hook relation".
™
Wind the thread on the needle.
™
Use the thread guide equipped with felt
pad.
™
Refer to "4-14. Needle-to-hook relation".
™
Refer to "4-14. Needle-to-hook relation".
™
Tighten the presser spring regulator.
™
Refer to "4-14. Needle-to-hook relation".
™
Replace the needle by thicker ones.
™
Wind the thread on the needle.
™
Thread the bobbin case correctly.
™
Remov e rough surfac e u s i ng a f i ne
sandpaper or polish the surface using a
bufng wheel.
™
Replace the bobbin or the hook.
™
Refer to "6-4. Adjusting the inner hook
guide".
™
Adjust the bobbin thread tension.
™
Adjust the tension components on the
bobbin winder.
TROUBLES
1. Thread
breakage
(Thread is
untwisted or
scraped.)
(Needle thread 2
to 3 cm is left on
the wrong side
of the fabric.)
2. Stitch skipping
3. Loose stitch
CAUSES
1
There is a sharp edge or burr on the
thread path, needle point, hook blade
point or bobbin case resting groove on
the throat plate.
2
Needle thread tension is too high.
3
Bobbin case opening lever provides an
excessive clearance at the bobbin case.
4
Hook blade point hits the needle.
5
Hook is not lubricated properly.
6
Needle thread tension is too low.
7
Thread take-up spring is too tight and its
stroke is too small.
8
Needle-to-hook timing is wrong.
9
Thread untwists.
!0
Uniform thread loops cannot be formed
when making chain-off thread.
1
Clearance between the needle and the
hook blade point is too great.
2
Needle-to-hook relation is wrong.
3
Pressing force of the presser foot is not
enough.
4
Needle bar height is wrong.
5
Needles are a little too thin.
6
Synthetic thread or thin thread is used.
1
Bobbin thread does not pass through
the forked end of the tension spring on
the bobbin case.
2
Thread path has rough surface.
3
Bobbin does not spin smoothly.
4
Bobbin case opening lever provides too
much clearance at the bobbin.
5
Bobbin thread tension is too low.
6
Bobbin is wound too tightly.

JUKI LH-3528 Specifications

General

Brand	JUKI
Model	LH-3528
Category	Sewing Machine
Language	English