Sewing Machine Keeps Knotting | 11 Common Issues

There is not a lot of things that are more frustrating when you are sewing than when your machine gets jammed, or your thread knots up.

This can slow down your project or even ruin your seams and fabric. When you spend money on fabric and thread, it can be expensive, so you do not want to waste any.

Knowing why your thread is knotting up can help you avoid it in the future and can help you fix it when it does happen.

Possible Problems:

The sole purpose of a sewing machine is to make your sewing project easier for you.

However, if you are having issues with your sewing machine, it could actually hinder your project completion or could do damage to your project.

There are a few potential issues that you could be experiencing if your thread is knotting or bunching up when you are using the sewing machine.

1. Dull Needle:

The point of the needle is responsible for catching your bobbin thread for you while sewing. When the needle does this, it makes a loop and creates a knot with the top thread.

This is how you create seams with your sewing machine.

However, if your needle is dull, this process might not work properly and can cause a knot to get stuck in the bobbin area instead of the fabric like it is supposed to.

This is a very simple issue and can be fixed by changing out your sewing machine’s needle to a new and sharp needle.

2. Incorrect Threading:

If you did not thread your machine correctly, you could run into issues in regards to your thread not working properly.

Threading the top thread incorrectly does not only affect the top thread, but it can also affect how the bobbin thread works.

If the top thread doesn’t work, the bobbin thread won’t be pulled up into the fabric the way that it should be.

Another potential issue with not properly threading your machine is that your top thread can get stuck or catch on a moving piece of the machine.

The top thread, when not threaded correctly, won’t flow easily through the machine and can create a tangle, knot, or can even break.

To correct this issue, you will want to completely rethread your top thread.

3. Thread Tails too Short:

When you are threading your machine and setting up to start sewing, you need to pay attention to your thread tails.

This is for both the top and bobbin threads. If your thread tails are not long enough, they could get pulled back into the sewing machine, which can cause a few different types of knotting.

When you thread your machine, you will want to make sure that you have a tail that is at least 5-6 inches or about 15 centimeters long. This will help you make sure that your tails do not get sucked back into your machine and cause knotting.

You can also lightly hold onto the thread tails with your fingers while you get your seam started.

If you happen to have your thread tails sucked back into your machine, you will just have to pull the thread out and rethread your machine.

4. Bobbin Placement Issue:

If the bobbin or bobbin case is not properly set in your machine, you could also have a problem. If you put the bobbin in your case wrong, then your bobbin thread might unwind the wrong way.

If your bobbin thread isn’t unwinding correctly, your bobbin thread and the top thread will not interact properly.

The bobbin and top thread won’t form the knots needed to make the stitches. Instead, there will be a large tangles mess underneath your project.

To make sure this doesn’t happen, make sure you properly place your bobbin in the bobbin case. You will want to make sure that the thread is set to unwind in a counter-clockwise direction. This means that your thread will pull from the left side to the right side of the bobbin.

You could also have your bobbin case insert into the machine incorrectly. This most often happens after you take your bobbin area apart to clean your machine.

You just want to make sure that when you take your machine apart to clean, that everything goes back in the place where it is supposed to be.

5. Bobbin Size Issue:

In addition to a bobbin placement issue, you could also have an issue with the size of your bobbin.

Most machines come with a couple of bobbins, but most sewers use tons of them so that they do not have to keep replacing the thread on them so that they are not wasteful.

At any sewing supply store, you can get a pack of new bobbins to use. Bobbins, however, are not all the same. This means that you want to make sure you get the proper bobbin for your specific sewing machine.

If the bobbin is too big or too small, you could have jamming from your bobbin. You could also have issues where your needle knocks into your bobbin, which can bend it or otherwise damage your needle as well as causing your thread to knot up.

To make sure this doesn’t happen to you, you will want to make sure that you buy bobbins that are specifically made to fit your machine or are compatible with your machine.

6. The Tension isn’t Equal:

One of the major issues that can cause knotting and bunching in your thread are tension issues. Tension issues are one of the most common causes of knotting, and bunching is tension issues.

For ideal tension, you will want to make sure the top thread and bobbin thread are set to equal tension.

If your top thread and your bobbin thread do not have the same tension, you could get multiple different types of knotting or other seam issues.

To adjust tension issues, you will want to start by adjusting the top thread. This can be achieved by changing the tension dials on your sewing machine.

If you need to change the tension with your bobbin thread, this is accomplished on the bobbin case. There is a screw on your bobbin case that you can tighten or loosen to increase or decrease the tension of your bobbin thread.

7. The Tension isn’t right for your thread or fabric:

If your tension is equal and you are still having issues, you could still have a problem with your machine’s tension.

This issue could come from the materials that you are using. If you are using a heavier fabric or thread, you will need to change your tension.

You might also need to change the needle that you are using.

You will also need to check your tension if you are using lighter and more delicate fabrics or threads.

The best way to make sure that your tension works with your fabric and thread is to use a test scrap of fabric and make sure that your seams work on it.

This will help you to prevent tangles and issues with the fabric you are using for your project.

What is The Correct tension for my sewing machine?

There is no such thing as a “correct” or “one-size-fits-all” tension. The tension that you need will depend on the thread and fabric that you are using.

If there is a type of thread that you use often, you can keep an extra bobbin case set to the corresponding tension, so you do not have to constantly adjust it whenever you choose a new thread.

This way, it will be easy to change out threads that you use often and will help to take the guesswork out of changing the bobbin tension.

You will know that your tension is correct on your machine if you can sew an even and flat seam on your fabric.

8. Dirty Machine:

If you do not regularly clean your sewing machine, you could also have issues with your project and your thread.

When you do not regularly clean your machine, it can be clogged with lint, debris, thread pieces, or even old fabric.

When your machine is full of dirt and other debris, the needle and thread can get stuck or jammed and cause knotting and other issues.

To fix this, you will want to clean out your machine and bobbin area. A good way to clean out all the dirt and debris is to use canned air. This is an easy way to clean the parts of your machine that you cannot reach and won’t damage your machine.

If you don’t have canned air and you have areas in the machine that you can’t reach, you will want to clean the area as carefully as possible.

Bumping or accidentally moving the inner parts of your machine can cause unseen damage or can knock your components out of place.

Cleaning your machine regularly is a good way to preserve the life of your machine and should be done often, even with everything in good working order.

9. The Machine is Not Oiled:

Another regular maintenance task that you should do with your machine is to oil it regularly.

Oiling your machine can keep it running smoothly and prevent your parts from wearing on each other. This also means that your machine will run longer and is less likely to get jammed.

If your machine is not running properly, you could get jams in the machine.

Not only that, but your machine timing could also be thrown off. If your machine timing is off, your needle and bobbin will not work together properly.

This can cause bunching, knotting, and other issues.

Keeping your machine oiled can also prevent you from having to take your sewing machine in to get serviced for a timing issue, wear and tear, or other issues that can make your machine stop working.

10. Where you Start your Seam:

If you try to start your seam too close to the edge of your fabric, you can be asking for your thread to form knots or jam.

If your needle catches your thread where there is not any fabric, you can cause knotting in your thread.

To avoid this, you will want to start sewing slightly farther into your project. A good practice to start your seam is to start sewing slightly away from the edge of your fabric.

Then you will want to reverse the stitch to make sure the stitch is solid and does not have a chance to unravel.

11. Thread Bunching in Bobbin Case:

If you have thread bunching in your bobbin case or you have other types of debris gathering in your bobbin case, you can have build up in under your needle plate.

This can cause your thread to bunch into a ball and create what looks like a birdnest.

This is a very easy situation to resolve if you are experiencing it. One of the most common reasons that this can happen starts in the bobbin.

Knotting, birdnesting, and bunching – is it all the same thing?

Knotting, birdnesting, and thread bunching are very similar but are not all the exact same problems.

All three of these problems can be very frustrating when you are sewing as they can ruin your project and can hinder your progress.

The main difference that exists between these types of thread issues is not what the thread is doing but instead is about where the knotting of the thread is located.

Each of these types of thread malfunctions can be caused by the issues that were listed above in this article.

More specific descriptions of these issues include:


Knotting in your thread is when the top thread and the bobbin thread are not interacting properly.

When your threads experience knotting, it usually occurs on the backside of the fabric.

This is normally due to the bobbin continuing to pull and jam while collecting a lot of thread beneath your fabric.

You will also likely experience large loops on the back of your fabric amid the knots.


Birdnesting is when the thread bunches up underneath your needle plate. Birdnesting can cause issues of its own.

These issues include broken threads, uneven tension, and even skipped stitches.

If you do not fix your birdnesting issue, it can cause other issues. After you diagnose the reason that your machine is birdnesting, you will want to make sure that you completely clean out the area underneath your needle plate.

If you leave some small thread or fabric fragments underneath the needle plate, you could have other issues occur in the future.

Birdnesting can occur anytime that there is a build-up of thread underneath the needle plate.

This could be caused by a few of the possible problems listed in the article above.


Fabric bunching takes place on top of your fabric.

This is very similar to the knotting that can occur underneath your fabric but instead rests on top of it.

This can be extra frustrating when it happens on top of your fabric because it can ruin the front face of your fabric and project.

Like the other issues, the cause could be a tension issue or another one of the above issues that have already been listed in this article.

So What Can I Do?

The main thing that you can do when you are trying to avoid thread issues is very simple.

These things include:

  • Keep your machine clean.
  • Keep your machine oiled.
  • Pay attention to your thread tension.
  • Make sure your bobbin is threaded and placed properly.
  • Make sure you are using the proper needle and tension for your thread or fabric.
  • Use the same thread for your top thread and your bobbin thread.
  • Make sure you are following the directions from your user manual.
  • Tug on both of your threads to see if they both pull easily.
  • Make sure nothing is damaged.
  • Test your seam on a test scrap of fabric.

If you follow the directions above, you can help yourself avoid any thread issues.

But if you do happen to have a thread issue, you will want to resolve it immediately to ensure you don’t have any more problems.

Taking care of any issues that you have can save your machine and your project from damage.

Both your sewing machine and your fabric cost money, so you will want to make sure that you do not allow anything that might cause damage.