APPENDIX
62
Upper thread tightened up
■
Symptom
• The upper thread appears as a single
continuous line.
• The lower thread is visible from the upper side
of the fabric. (Refer to the illustration below.)
• The upper thread has tightened up, and comes
out when pulled.
• The upper thread has tightened up, and
wrinkles appear in the fabric.
• The upper thread tension is tight, and the
results do not change even after the thread
tension is adjusted.
1
Lower side of fabric
2
Lower thread visible from upper side of fabric
3
Upper thread
4
Upper side of fabric
5
Lower thread
■
Cause
Incorrect lower threading
If the lower thread is incorrectly threaded, instead
of the appropriate tension being applied to the
lower thread, it is pulled through the fabric when
the upper thread is pulled up. For this reason, the
thread is visible from the upper side of the fabric.
■
Remedy/check details
Correctly install the lower thread.
• Refer to “Lower threading” (page 14-16).
Tangled thread on wrong side of
fabric
■
Symptom
• The thread becomes tangled on the lower side
of the fabric.
• After starting sewing, a rattling noise is made
and sewing cannot continue.
• Looking under the fabric, there is tangled
thread in the bobbin case.
■
Cause
Incorrect upper threading
If the upper thread is incorrectly threaded, the
upper thread passed through the fabric cannot be
firmly pulled up and the upper thread becomes
tangled in the bobbin case, causing a rattling
noise.
■
Remedy/check details
Remove the tangled thread, and then correct the
upper threading.
1
Remove the tangled thread. If it cannot be
removed, cut the thread with scissors.
• For details, refer to “Cleaning the race” (page
60).
2
Remove the upper thread from the machine.
3
Correct the upper threading by following
the instructions in “Upper threading” (page
16).
• If the bobbin was removed from the bobbin
case, refer to “Lower threading” (page 14)
and “Remedy/check details” in the section
“Upper thread tightened up” (page 62) to
correctly install the bobbin.
Incorrect thread tension
■
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.