APPENDIX
■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.
❏ 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
■Cause/remedy/check details
❏Cause 1
The machine is not correctly threaded.
<With symptoms 1 and 2 described above> The bobbin threading is incorrect.
Return the upper thread tension to the standard setting, and then refer to “Upper thread tightened up” (page 151) to correct the threading.
<With symptoms 3 through 5 described above> The upper threading is incorrect.
Return the upper thread tension to the standard setting, and then refer to “Tangled thread on wrong side of fabric” (page 152) 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 38) to check that a needle and thread appropriate for the fabric are being used.
❏Cause 3
An appropriate setting on the thread tension dial is not selected.
The setting selected for the upper thread tension is not appropriate. Refer to “Changing the tension of the upper thread” (page 58) to select an appropriate thread tension. The appropriate thread tension differs depending on 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
zIf the upper threading and bobbin threading are incorrect, the thread tension cannot be adjusted correctly. Check the upper threading and bobbin threading first, and then adjust the thread tension.
❏If the bobbin thread is visible from the right
side of the fabric
Press 
(Thread tension key) in the operation panel to decrease the tension of the
upper thread.
❏If the upper thread is visible from the wrong side of the fabric
Press 
(Thread tension key) in the operation panel to increase the tension of the
upper thread.
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