Thread keeps breaking

Incorrect threading.

Bad tension settings top and bobbin.

Bad quality thread. Cotton can go rotten as it is organic.

Other ideas in textual form and videos.

7 Common Causes of Thread Breaks in Embroidery

Lawson Screen & Digital Products https://lawsonsp.com > blogs > education-and-training

Jan 20, 2020 - Thread breakage can cause production issues for embroidery businesses. From improper threading to needle issues, here's an overview.

Embroidery Machine Thread Breaking & Shredding: 10 Fixes

Sewing Machine Fun https://www.sewingmachinefun.com > embroidery-ma...

Jul 10, 2023 - 1. Change Needles. ... If your needle has a burr or is dull or bent, it can cause issues with your thread. To rule out needle issues, switch to a ...

20+ Reasons Your Sewing Machine Thread Keeps ...

Ageberry https://www.ageberry.com > sewing-machine-thread-k...

Jan 31, 2023 - 10. Your Bobbin Isn't inserted Correctly. Your bobbin could be inserted incorrectly, leading to thread breaks. Solution: Check your bobbin to ...
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Make sure the correct length of needle is used and installed correctly. Sometimes it moves slightly out of the holder without falling out but just enough to affect the needle eye position which can cause this kind of problem. For thicker materials use either ball point or denim needles. As last resort the top thread tension might be too tight. Adjust the top thread tension.

1. Set up for regular sewing (not embroidery).
2. Adjust the tension of the bobbin and the top thread so that you have a nice straight stitch.
3. Check your thread quality. Is it fuzzy or have small trails sticking out. No Walmart thread allowed. Only top notch embroidery thread allowed.
4. When you've been successful with the thread and tension go ahead and set up for free arm.
5. Sew free arm but remember machine has to keep up with you. If you go too fast you will be pulling the thread and probably will break the thread.
6. Your erratic stitch is caused by the speed at which you are moving the hoop. Going fast; then slow is going to make a long stitch and then a short stitch, etc.

1. Maybe you are using the wrong size machine needle or poor quality thread.
2. You must always lift the presser foot before threading the machine to release the tension discs.
3. Maybe you have broken thread stuck in the discs or bobbin race. Give them a clean. Pull a thicker thread by hand through the tension discs when the presser foot is up.

The timing needs to be adjusted and if you are the original owner, this has to be done by an authorized Janome dealer to prevent invalidation of your warranty.

This is something that you should not attempt least more problems arise.

My bobbin case was jumping all the time...had it in for repairs and would bring it home and even though the tech had attached a test sew piece with different colored bobbin and top thread I could not get it to sew without the bobbin jumping. I thought that he had lied about that being sewn on this machine...finally, I found that you should start with plenty of thread in your hand when threading machine...so that once you feel it click into the tension...DO NOT PULL the thread, it pops it out of the tensioner...just loosely thread and hold tension with your thumb and forefinger while using the needle threader.

you ten. should be on 2.5

It sounds like the machine needs to be timed, seek out a sewing machine repair shop for this service.

I HAVE THE SAME PROBLEM WITH THREAD BREAKING. HAVE TRIED EVERYTHING. FINALLY I GOT SOME UPHOLSTERY THREAD AND IT SEAMS TO WORK MUCH BETTER. NOW i AM HAVING TROUBLE FINDING THE NEEDLES FOR THIS MACHINE. NOT HAPPY WITH MACHINE AT ALL

Sounds like a bobbin tension problem.  Check to see if a small thread is caught in the bobbin case or try a new bobbine