Incorrect Thread Tension
Symptoms
Symptom 1: The bobbin thread is visible from the right side of the fabric.
Symptom 2: The upper thread appears as a straight line on the right side of the fabric.
Symptom 3: The upper thread is visible from the wrong side of the fabric.
Symptom 4: The bobbin thread appears as a straight line on the wrong side of the fabric.
Symptom 5: The stitching on the wrong side of the fabric is loose or has slack.
Symptom 1 | Symptom 3 |
 |  |
- Wrong side of fabric
- Bobbin thread visible on right side of fabric
- Upper thread
- Right side of fabric
- Bobbin thread
- Upper thread visible from wrong side of fabric
Cause/Remedy
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 Setting the Bobbin to correct bobbin 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 Upper Threading to correct the upper threading.
Cause 2
A needle and thread appropriate for the fabric are not being used.
The 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 Fabric/Thread/Needle Combinations to check that a needle and thread appropriate for the fabric are being used.
Cause 3
An appropriate upper tension is not selected.
Adjust the upper thread tension 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.
- If the upper threading and bobbin threading are incorrect, the thread tension cannot be adjusted correctly, even by adjusting the upper thread tension. Check the upper threading and bobbin threading first, and then adjust the thread tension.
When the bobbin thread is visible on the right side of the fabric, set the upper thread tension to a lower number. (Loosen the thread tension.)
When the upper thread is visible on the wrong side of the fabric, set the upper thread tension to a higher number. (Tighten the thread tension.)
