The thread started to loop: why and how to fix it?

When the thread starts to loop on an overlock machine, it usually indicates a tension issue or a threading problem. Here's how to diagnose and fix the problem:

Check threading: Ensure that the machine is threaded correctly according to the threading diagram in the manual. Start by rethreading the machine from scratch, making sure to follow each step carefully. Pay close attention to threading the upper and lower loopers and needles. Even a small misstep in threading can cause looping issues.

Check tension: Improper tension settings can also cause looping. Check the tension dials for the upper and lower loopers. Generally, for a balanced stitch, the tension dials should be set to a similar number. However, the exact tension settings may vary depending on the fabric and thread you're using. Refer to your machine's manual for recommended tension settings for different fabrics and stitches. Adjust the tension dials accordingly, and test sew on a scrap piece of fabric to see if the looping improves.

Check needles: Bent or dull needles can also cause looping. Replace the needles with new ones of the appropriate size and type for your fabric. Make sure the needles are inserted correctly and securely into their respective positions.

Check for lint and debris: Buildup of lint, dust, or thread fragments in the machine's tension discs, needle area, or loopers can also cause looping. Clean the machine thoroughly, especially around the tension discs, needle plate, and loopers. Use a brush, compressed air, or a lint roller to remove any debris.

Check differential feed: In some cases, incorrect settings on the machine's differential feed can lead to looping. Ensure that the differential feed is set to the appropriate ratio for the fabric you're using. Experiment with different settings until you achieve smooth stitching.

Check for other issues: If looping persists despite checking and adjusting the above factors, there may be other mechanical issues with the machine, such as timing problems or worn-out parts. In such cases, it's best to consult a professional sewing machine technician for diagnosis and repair.

By systematically checking and addressing these potential causes, you should be able to resolve the looping issue on your overlock machine and achieve smooth and even stitches.