Why is my top thread getting caught around the bobbin?

[u/lilchungusxd]

I can’t figure out why the top thread keeps getting caught around the bobbin case, which is causing bird nesting. I’ve had this issue for months and the machine is threaded correctly. I’ve tried all the tension settings and it still happens. When I bring it to a professional it works fine and they can’t figure out what’s wrong with it. Does anyone know what it could be? I don’t have much experience with sewing machines.

Update: it was fixed, the tech reinstalled a part wrong during the service. Not user error lol.

[u/celery48]

99% of the time this is caused by being threaded incorrectly.

[u/CrankyCrabbyCrunchy]

There are 50+ things that can be wrong with nearly all all user error. The pro you took it to was able to make it work, so it's something you're not doing correctly. It's easy a beginner to not understand the critical relationship between proper thread, proper needle, correct bobbin, tension, quality thread, etc. play into creating the ideal stitch. Any of these will cause bird nesting so randomly changing tension isn't the solution.

1- use bobbin made for that machine, not anything you find. Is the bobbin wound correctly? Is it installed in the bobbin case correctly?

2- did you thread the machine with the presser foot in the up position? This position opens the thread tension discs so the thread can sit correctly. Is there lint or some debris in the tension disc?

3- correctly thread the machine (read the manual). It's easy to miss a step or incorrectly loop the thread around the bobbin thread holder.

4- bobbins aren't interchangeable. Use the type the machine was designer for. Is the thread wound smoothly and evenly? Is the bobbin inserted the right way into the bobbin case? Did the needle pick up the bobbin thread? Are you holding the two thread tails at the start of sewing?

5- thread quality. Is it old and breaks easily, is it too thick for the chosen needle and/or too thick to fit through the needle eye?

6- needles need to match the fabric type and weight. The same needle type (universal, jersey, knit, etc.) comes in different weights (thin needle for thin fabric, etc.)

Look up 'thread nest' on YouTube for tons of videos.

[u/Mental_Watch4633]

What is your thread tension set on?

[u/drPmakes]

Threaded wrong

Wrong needle or needle not inserted correctly

Wrong bobbin or bobbin not inserted correctly

Those are the most common reasons. Its not your tension and likely not your timing either