TROUBLESHOOTING

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.

□Symptom 1

□Symptom 3

a Lower side of fabric

b Lower thread visible on 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

□Cause 1

The machine is not correctly threaded. <With symptoms 1 and 2 described above> The lower threading is incorrect.

Adjust the upper thread tension and then refer to “Upper Thread is Too Tight” on page 80.

<With symptoms 3 through 5 described above> The upper threading is incorrect.

Adjust the upper thread tension and then refer to “Tangled thread on wrong side of fabric” on page 344 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 “Fabric/Thread/Needle Combinations” on page 69 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.

Note

•If the upper threading and lower threading are incorrect, the thread tension cannot be adjusted correctly, even by adjusting the upper thread tension. Check the upper threading and lower threading first, and then adjust the thread tension.

* When the lower thread is visible on the upper 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 lower side of the fabric. Set the upper thread tension to a higher number. (Tighten the thread tension.)

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