Why is this happening and what can I do to correct it?
 

I use a Brother CS6000i and this started this week! I have cleaned it, changed the needle and bobbin and retreaded. I don't mess with the tension. This is on the bottom and happens at the beginning of stitching. It was bird nesting too but that must have straightened out with all the work I did

If it happens only at the beginning of your stitching, try holding both thread tails for the first 5 or so stitches.

There's no law against adjusting your tension. If the ubiquitous "they" didn't want you to change the tension, they wouldn't make knobs and screws for that purpose. :thumbup:

If holding your thread tails doesn't stop the issue, then you need to adjust the tension. If the problem is on the bottom of your stitching, then the issue is with your top thread. Tighten it by turning the knob a quarter turn and then test your stitching again.

It's like the thread doesn't start in the upper tension -- like it has to work up to getting to the tension disks. The thread guide (top, back of the machine) that the thread goes into, before it goes into the tension disks, has 2 positions on it. One position is for bobbin winding, which is the little pre-tensioner on the left. The other position is for sewing, which starts behind and under on the right side.

If you've got it in the correct position, and it isn't working for you, try putting it in the pre-tensioner. For some machines, that little change is just the magic the machine needs.

Also, I have to add that if you're using a funky thread, that could also be an issue. I'm talking about "hand quilting" or "outdoor" thread, etc.

And one last thought... If there's damage on the hook, that can also give you loops.

Good Luck with your machine!

Don't use hand quilting thread on your machine.

Did you put the bobbin case in before you put the needle plate on when you cleaned it out because you have to put needle plate on first before you put bobbin case in

I suspect that there's something blocking the top thread path. Could there be a bit of thread stuck in the tension mechanism?

Turn your wheel where your needle is all the way to the top, thread your needle at this position. Lower pressure foot. Hold your needle thread to the side and bring your needle down thru the fabric, pull on your top thread you are holding onto. This will bring your bobbin thread to the top of your fabric. Lift your presser foot and place your threads towards the back of the machine. Lower foot and start stitching. See if this steps helps.
It looks like your top thread has no tension for the first few stitches. Also clean your tension discs. If the thread is not "seating" in the discs to begin with, it will cause the problem you are having. Also thread not in the take up lever will do the same. however if it was the take up lever, your stitches would continue to loop. It is in the beginning of your sewing.....double check all guides and tension areas as you thread your machine, to make sure your thread is "seated" properly. Your top thread is not under tension for those first seven stitches...Most problems that create tension issues such as having your thread solidly in the tension discs and it is making the loops, means your tension is not correct all the time, so the loops would continue. Yours is only the first seven stitches....that sounds like the thread is not getting solidly into the tension area of your discs, or the inch or so of your thread is loose from the take up lever not being up with your needle in the highest position. Are you bringing your bobbin thread to the top of your machine before placing your fabric under the pressure foot? This would cause nesting and looping, but mostly nesting under your needle plate. Is your thread on the upright spool holder? or do you have it on a spool stand?.
Whatever is happening is happening in the first seven stitches, then it corrects itself. I wish I could be there to help you....sometimes our machines are finicky, sometimes it is a simple thing that we are doing or not doing. It really sounds like your thread is coming out of the take up lever, but then your stitches are OK, so that doesn't make sense to me...so, I would change the type of thread you are using. Thread your machine with the needle position at highest level. Bring your thread to the top of your needle plate or even the top of your fabric, lower the pressure foot. AND WATCH YOUR thread as it is fed from the take up lever to the needle. Here is a link to threading the machine, which I'm sure you have done many times..... but could be a reminder.
https://www.instagram.com/explore/ta...hreadabrother/

This is what causes similar problems in one of my machines at times. If you are showing us the bottom side, it's the top tension that is not feeding the thread correctly. I know that's counterintuitive because the top side of the stitches may actually look quite normal. I don't really understand the logic of machine designers who have made the thread path out of sight for us, so that what might have been a simple problem on an old fashioned machine is completely inside where we can't see it and can't get at it.

The first thing I can suggest is to try a technique when threading it a bit like when you floss between your teeth. Be sure to hold the thread firmly above and below as you pull it through the area where the tension is, so that it has a better chance of engaging. The presser foot should be up when threading so that the tension is disengaged and the thread can get in. The manual will probably specify where it's important to hold the thread firmly as you thread it. If that doesn't work, you may need a technician. If you're lucky, maybe you can find a tech person who will do a diagnostic while you wait and charge a small fee if all he/she has to do is pull out the snarl with tweezers. This is not covered by the Brother warranty (I was told), because it's considered user error. It's certainly an argument for quality thread, but even the best ones will sometimes have a flaw. My Brother is an embroidery machine, but the thread path is very much the same as on my Singer and Baby Lock machines.

If (and only if) the machine is out of warranty, you could look around for a screw or two that might give you access to that area yourself. I have been able to pull out a snarl from my tension (on a new-ish Singer) using a tiny steel crochet hook. Don't bend, scratch or force anything! Unplug first, of course. If you see thread inside there when the machine is not threaded, that's pretty solid evidence of what's wrong. When I did it, I found a short piece of thread wound tightly at least 30 times. It was worth my time to deal with it only because the Singer repair place was an hour and a half away.

One of my machines does this sometimes. I don't fret over it. I use a starter piece of a fabric to sew on first, some call it a leader. If it was a problem that needed a repair it wouldn't magically start sewing correctly. It is usually a user error.

This happened with my crescendo. Tried a old bobbin case and it fixed it. Ordered a new one and set the one that didn't work on the side of the machine. After a few days I noticed that the vibration had dislodged a VERY small piece of thread from the bobbin case. Now it works perfectly and I have an extra case! May not be the same thing with yours but check very carefully for dust or thread bits stuck in the machine.