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APPENDIX
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Incorrect thread tension
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Symptoms
• Symptom 1: The lower thread is visible from the upper side of the fabric.
• Symptom 2: The upper thread appears as a straight line on the upper side of the fabric.
• Symptom 3: The upper thread is visible from the lower side of the fabric.
• Symptom 4: The lower thread appears as a straight line on the lower side of the fabric.
• Symptom 5: The stitching on the lower side of the fabric is loose or has slack.
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Cause/remedy/check details
Cause 1
The machine is not correctly threaded.
<With symptoms 1 and 2 described above>
The lower threading is incorrect.
Return the upper tension-control dial to “4”,
and then refer to “Upper thread tightened up”
(page 98) to correct the threading.
<With symptoms 3 through 5 described
above>
The upper threading is incorrect.
Return the upper tension-control dial to “4”,
and then refer to “Tangled thread on wrong
side of fabric” (page 99) to correct the upper
threading.
Cause 2
A needle and thread appropriate for the
fabric are not being used.
The sewing machine needle that should be
used depends on the type of fabric sewn and
the thread thickness.
If a needle and thread appropriate for the
fabric are not being used, the thread tension
will not be adjusted correctly, causing
wrinkles in the fabric or skipped stitches.
• Refer to “Needle types and their uses”
(page 31) to check that a needle and thread
appropriate for the fabric are being used.
Cause 3
An appropriate setting on the upper tension-control dial is not selected.
Turn the upper tension-control dial to select an appropriate thread tension.
The appropriate thread tension differs according to the type of fabric and thread being used.
* Adjust the thread tension while test sewing on a piece of scrap fabric that is the same as that used in
your project.
Note
●
If the upper threading and lower threading are incorrect, the thread tension cannot be adjusted
correctly, even by turning the upper tension-control dial. Check the upper threading and lower
threading first, and then adjust the thread tension.
• When the lower thread is visible from the
upper side of the fabric. Turn the upper
tension-control dial to a lower number
(toward the left). (Loosen the thread tension.)
• When the upper thread is visible from the
lower side of the fabric. Turn the upper
tension-control dial to a higher number
(toward the right). (Tighten the thread
tension.)
Symptom 1
Symptom 3
a
Lower side of fabric
b
Lower thread visible from
upper side of fabric
c
Upper thread
d
Upper side of fabric
e
Lower thread
f
Upper thread visible from
lower side of fabric
4
3
5
4
3
5