JUKI
MH-380, Инструкция по эксплуатации

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Troubles Causes Corrective measures
2 An independent seam is skipped on the
looper thread.
Needle
Looper
This trouble is caused when the needle
failed ·to come down through a trian-
gular loop formed by the looper thread.
™ Verify the looper motion.
Verify the clearance between the looper and
the needle.
Refer to “17. NEEDLE-TO-LOOPER RELA-
TION”.
™ Check the timing of the looper thread take-up.
Refer to “19. POSITIONING THE LOOPER
THREAD TAKE-UP”.
™ Increase the looper thread tension slightly.
Refer to “8. THREAD TENSION”.
™ Verify the thread is correctly passed through.
Refer to “6. THREADING THE MACHINE
HEAD” and “7. THREADING THE LOOP-
ERS”.
3
Seam is skipped on the needle thread
due to insuf fi cient interlooping.
Needle
Looper
This trouble is caused when the needle
thread is inclined extremely to the left.
™ Verify the looper motion.
Verify the clearance between the looper and
the needle.
Refer to “17. NEEDLE-TO-LOOPER RELA-
TION”.
If it is caused in the use of a chemical
fi ber thread.
™ Reduce the sewing speed.
™ Apply silicon oil lubricant.
Refer to “11. ATTACHING THE NEEDLE”.
™ Use a needle for chemical fi ber threads.
If it is caused in the use of a synthetic
fi ber thread.
™ Reduce the sewing speed,.
™ Apply silicon oil lubricant.
Refer to “11. ATTACHING THE NEEDLE”.
3. Inadequate tight-
ness of stitches
1 Needle thread tension is too low. ™ Tighten the needle thread tension nut.
Refer to “8. THREAD TENSION”.
2
Looper thread tension is too high. ™ Loosen the looper thread tension nut.
Refer to “8. THREAD TENSION”.
3
Looper thread take-up does not supply
a suf fi cient length of thread.
™ Change the threading order in the looper thread
guide.
Refer to “19. POSITIONING THE LOOPER
THREAD TAKE-UP”.
4
Thread is too thick for the needle size. ™ Try to use a different needle.
Refer to “11. ATTACHING THE NEEDLE”.
5
Set position of the frame thread eyelet
is not suitable.
™ Try to lower the position.
Refer to “21. POSITION OF THE FRAME
THREAD EYELET”.
6 Position of the thread take-up lever is
not suitable.
™ Try to push it up.
Refer to “20. POSITION OF THE THREAD
TAKE-UP LEVER”.
7
Throat plate does not fi t. ™ Replace it with other throat plate which has
larger needle hole.
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