Troubles And Corrective Measures - JUKI LBH-1790 Instruction Manual

(. TROUBLES AND CORRECTIVE MEASURES

Troubles
. Needle thread break- . Thread tenson at parallel secton s too hgh.
age
2. Pressure or stroke of thread take-up sprng s
3. There s a burr or scratch on the blade pont
4. Hook tmng s not proper.
5. There s a scratch on the thread path.
6. Attachng needle s wrong.
7. Needle s too thn.
8. Needle tp s damaged.
2. Needle thread slps off. . Needle thread trmmer opens too early.
2. Whp sttchng s not formed at the start of
3. Threadng needle thread s wrong.
4. Speed at the start of sewng s too fast.
3. Wobblng at parallel . Thread tenson at parallel secton s too low.
secton
2. Bobbn thread tenson s too hgh.
3. Pre-tenson s too low.
4. Wobblng at the start . Thread tenson at parallel secton s too low.
of sewng
2. Poston of needle thread trmmer s too hgh.
3. Stroke of thread take-up sprng s too large.
5. Needle thread ap- . Bar-tackng thread tenson s too low.
pears on the wrong 2. Bobbn thread tenson s too hgh.
sde of materal at
bar-tackng secton n 3. Number of sttches of radal shape s too many.
dumplng condton. 4. Tenson at the end of sewng s too low.
6. Stitches float. . Bobbn thread tenson s too low.
2. Bobbn thread comes off bobbn case.
7. Sttch skppng . Button hole s small n terms of the sze of
2. Material flops because of light-weight.
3. Attachng needle s wrong.
4. Needle s bent.
5. There s a burr or scratch on the blade pont
8. Thread frays. . Number of sttches of te sttchng s too small.
2. Wdth of te sttchng s too wde.
9. Length of needle . Wdth of te sttchng s too narrow.
thread remanng at
the end of sewng s 2. Tenson of te sttchng s too low.
too long.
0. Needle thread . Tenson at the start of sewng s too low.
breaks at the start of
sewng, or the wrong
sde of seam s drty.
Causes
too large.
of hook.
sewng.(Tenson at the start of sewng s too
hgh.)
presser.
of hook.
™ Decrease the thread tenson at parallel
secton.
™ Decrease the tenson of thread take-up
sprng or decrease ts stroke.
™ Buff the blade pont of hook. Or, replace
the hook.
™ Adjust agan the hook tmng wth tmng
gauge.
™ Polsh the thread path wth sand paper
and buff t.
™ Adjust agan the drecton, heght, etc.
™ Replace the needle wth a thcker one.
™ Replace the needle.
™ Delay the openng tmng of the needle
thread trmmer.
™ Decrease tenson at the start of sewng.
™ Thread properly agan.
™ Set the soft-start functon.
™ Increase the thread tenson at parallel
secton.
™ Decresase bobbn thread tenson.
(Purl sttchng : 0.05 to 0.N )
™ Increase pre-tenson.
™ Increase the thread tenson at parallel
secton.
™ Lower the needle thread trmmer to such
an extent that t does not come n contact
wth the presser.
™ Decrease the stroke of thread take-up
sprng.
™ Increase the bar-tackng thread tenson.
™ Decresase the bobbn thread tenson.
(0.05 to 0.N )
™ Decrease the number of sttches.
™ Increase tenson at the end of sewng.
™ Increase the bobbn thread tenson.
™ Perform proper threadng the bobbn case.
™ Take care that the wndng amount of bob-
bn thread s not excessve.
™ Replace the presser wth a smaller one.
™ Delay the hook-to-needle tmng.
(Lower the needle bar by 0.5 mm.)
™ Adjust agan the drecton, heght, etc.
™ Replace the needle.
™ Buff the blade top of hook. Or, replace the
hook.
™ Increase the number of sttches of te
sttchng at the end of sewng.
™ Narrow the wdth of te sttchng at the end
of sewng.
™ Wden the wdth of te sttchng at the end
of sewng.
™ Increase tenson at the end of sewng.
™ Increase tenson at the start of sewng.
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Correctve measures
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