You may need to change the thread tension, depending on the fabric and thread being used. Follow the steps below to make any necessary changes.
Proper Thread Tension
The upper thread and the bobbin thread should cross near the center of the fabric. Only the upper thread should be visible from the right side of the fabric, and only the bobbin thread should be visible from the wrong side of the fabric.
If the bobbin thread is visible from the right side of the fabric, the upper thread is too tight.
If the bobbin thread was incorrectly threaded, the upper thread may be too tight. In this case, refer to How do I set the bobbin ? and rethread the bobbin thread.
(1) Bobbin thread
(2) Upper thread
(3) Surface
(4) Locks appear on surface of fabric
Press , to loosen the upper thread.
When you finish sewing, remove the bobbin cover and then make sure that the thread is shown as below. If the thread is not shown as below, the thread is not inserted through the tension-adjusting spring of the bobbin case correctly. Reinsert the thread correctly. For details, refer to How do I set the bobbin ?
Upper Thread is Too Loose
If the upper thread is visible from the wrong side of the fabric, the upper thread is too loose.
If the upper thread was incorrectly threaded, the upper thread may be too loose. In this case, refer to How do I thread my machine ? and rethread the upper thread.
(1) Upper thread
(2) Bobbin thread
(3) Wrong side
(4) Locks appear on wrong side of fabric
Press , to tighten the upper thread.
Press to return the thread tension to the original setting.