ZOJE 5780BK, Operation Manual

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Trouble Causes Corrective measures Page
1.Needle thread
breakage
1. Thread tension at parallel section is too
high.
2. Pressure or stroke of thread
take-upspring is too large.
3. There is a burr or scratch on the blade
point of hook.
4. Hook timing is not proper.
5. There is a scratch on the thread path.
6. Attaching needle is wrong.
7. Needle is too thin.
8. Needle tip is damaged.
○
decrease the thread tension at
parallel section.
○
decrease the tension of thread
take-up spring or decrease its stroke.
○ Buff the blade point of hook. Or,
replace the hook.
○ Adjust again the hook timing with
timing gauge.
○ Polish the thread path with sand
paper and buff it.
○
Adjust again the direction, height,
etc.
○
Replace the needle with a thicker
one.
○更 Replace the needle.
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2. Needle thread
slips off.
1. Needle thread trimmer opens too early.
2. Whip stitching is not formed at the
start of sewing.(tension ).
3. Threading needle thread is wrong.
4. Speed at the start of sewing is too fast.
○
Delay the opening timing of the
needle thread trimmer.
○ Decrease tension at the start of
sewing.
○
Thread properly again.
○ Set the soft-start function.
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3. Wobbling at
parallel section
1. Thread tension at parallel section is too
low.
2. Bobbin thread tension is too high.
3. Pre-tension is too low.
○ Increase the thread tension at
parallel section.
○ Decrease bobbin thread tension.
○ increase pre-tension.
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4. Wobbling at the
start of sewing
1. Thread tension at parallel section is too
low.
2. Position of needle thread trimmer is
too high.
3. Stroke of thread take-up spring is too
large.
○ Increase the thread tension at
parallel section.
○ Lower the needle thread trimmer to
such an extent that it does not come in
contact with the presser.
○ Decrease the stroke of thread
take-up spring.
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5.Needle thread
appears on the
wrong side of
material at
bar-tacking section
in dumpling
condition.
1. Bar-tacking thread tension is too low.
2. Bobbin thread tension is too high.
3. Number of stitches of radial shape is
too many.
4. Tension at the end of sewing is too
many.
○ Increase the bar-tacking thread
tension.
○
Decrease the number of stitches
○ Decrease the number of stitches.
○
Increase tension at the end of
sewing.
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6. Stitches float. 1. Bobbin thread tension is too low.
2.Bobbin thread comes off bobbin case.
○
Increase the bobbin thread tension.
○ perform proper threading the bobbin
case.
○
take care that the winding amount of
bobbin thread is not excessive.
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7. Stitch skipping 1. Button hole is small in terms of the ○ Replace the presser with a smaller —
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