Bobbin tension or bottom tension is fixed by adjusting a small screw next to your bobbin case’s thread opening.To adjust, use a tiny screwdriver and turn the tiny screw to the right for tighter tension or the left to loosen bobbin tension. Sewing your project right always depends on the right thread tension.
There are three factors in play to make your sewing work successfully. These are the correct presser foot tension, top thread tension, and bobbin tension. But this time, we will only talk about the effect of bobbin tension on your sewing and how to fix it when something goes awry.
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When should I adjust the bobbin tension?
You will come across people who will tell you never to adjust the bobbin tension on your sewing machine. There is some truth to these words because, supposedly, bobbin thread tension has already been set in the factory. Tension adjustments are commonly made on the needle thread by turning the tension regulating dial.
If you had been using your sewing machine for quite some time, it is possible for your bobbin tension setting to change slightly. You may need to tighten or loosen your bobbin tension. Keep in mind that changing the bobbin tension should not be as frequent as adjusting the needle thread tension.
Aside from your bobbin tension shifting slightly with regular machine use, here are a few reasons why you need to change your bobbin tension.
1. You are sewing on thick or very light fabric.
Bobbin tension is usually set for ordinary sewing. But there would come a time when you need to sew thick fabric or a very light one on your household sewing machine. If you cannot get a proper stitch after adjusting the top thread tension, you may need to adjust your bobbin tension slightly.
2. You are using a very thick or very fine thread.
When you use a very thick or very fine thread, the same thing applies. It is possible you may not get smooth and straight stitches after adjusting the top thread tension. In these instances, you have the liberty to fix the bobbin tension.
3. You are using an unusual thread.
For common stitching, you may typically use the 50wt., all-purpose thread. If your sewing project requires you to use something like a 12wt thread, you may need to adjust the bobbin tension. Unusual thread weights work best with the bobbin tension suitable for these unique types of thread.
4. Your bobbin thread keeps breaking.
You keep getting skipped stitches, and your bobbin thread keeps on breaking, but you see no faults in any other sewing machine parts. It is time to adjust your bobbin tension.
5. You are using elastic thread for shirring.
It would help if you changed the bobbin tension when you are using elastic thread for shirring. Find the best bobbin tension setting that would work with an elastic thread for effective shirring.
6. Bobbin tension was not set at the factory.
This situation may occur very rarely on newly-bought machines. When you have crossed out all the possible factors, but you still create dreadful stitches, you may need to adjust your bobbin tension. Report to your dealer first. You may need your brand-new machine checked by a sewing machine technician.
Adjusting the bobbin thread tension should come to mind last when you are having problems with your stitches. There is a load of reasons you can check first. Do not readily assume that the bobbin thread tension is the culprit. It would be best if you crossed out these reasons first before you think of fixing the bobbin tension.
- Check if you thread your sewing machine correctly.
- Check if you are using the right bobbin size.
- Check if you inserted your bobbin correctly.
- Check if your presser foot is down and your feed dogs are put up when sewing.
- Check if you have the correct needle type and size, and proper thread weight for your fabric.
- Check for lint and dirt in your bobbin case.
- Check for nicks or scratches on the bobbin and bobbin case. Either the bobbin or bobbin case needs to be changed.
- Check if the needle tension assembly is worn out and needs to be replaced.
If none of these reasons are causing the stitching issues, then it is time to check your bobbin tension.
Adjusting the bottom tension of your sewing machine is relatively easy. But as mentioned earlier, changing the bottom tension should be your last resort.
You must know first that there are two ways to load bobbins in your sewing machine – the top-loading bobbin and the front-loading bobbin.
Also called the drop-in bobbin, this type of bobbin loading is commonly found in modern computerized home sewing machines. Bobbin used is usually made of plastic, and you drop the bobbin in (hence the name), and you are good to go. Machine brands that typically use this type of bobbin style are Janome and Viking.
These bobbins usually have metal bobbin cases typical for older sewing machines. Some sewing machine brands with front-loading bobbin are Bernina, Brother, Kenmore, Pfaff, and Singer.
Both bobbin cases use the same method of adjusting the bobbin. Both have an adjusting screw that can be turned to adjust the bobbin tension. Most sewing machines come with a small screwdriver that can be used to adjust the bobbin tension.
For both of these bobbin types, turning the adjusting screw to the right will increase the tension, and turning it to the left will loosen the tension. If the adjusting screw is difficult to turn, do not use force. Turning the screw too much in either direction may damage the bobbin case. It would be best to ask for help from a sewing machine technician.
How do I fix the tension on my bobbin thread?
Your sewing machine has good thread tension when it makes well-formed stitches. You will know if you sew stitches correctly when your top thread and your bobbin thread evenly lock together in the middle of your fabric. Simply said, your top thread is only on the top side of your fabric, and your bobbin thread is underneath the fabric.
If your bobbin tension is not behaving as it should be, you will know by looking at your two threads on the fabric. Your clue if you need to fix the tension on your bobbin thread is if it shows on the top of the fabric. Another hint is when your upper thread is too loose that you can pull it out quickly.
Before you do any tinkering on the bobbin adjusting screw to fix the tension, check first your bobbin tension to know if you need to loosen it or tighten it. Sewing machines have two ways of loading the bobbin; drop-in or top-loading bobbin and front-loading bobbin. These two types differ in checking bobbin tension but are similar in fixing the tension in bobbin thread.
- Front-loading Bobbin
To check your bobbin tension for the front-loading bobbin:
- Start by pulling out the bobbin case from the machine.
- Load in a freshly wound bobbin into your bobbin case.
- Make sure it is loaded with thread in the right direction.
Put your bobbin inside the bobbin case and guide the thread through a tiny slit on the side. Place your thread underneath the tensioning plate until you hear it click into place. If your bobbin thread has an extra little arm for embroidery functions, there is no need to put your thread on it.
Then, place your index finger and thumb where the thread comes out of the bobbin case and pinch the thread. Flick your wrist in a downward motion as if playing with a yoyo. But first, make sure that you have a soft surface if your bobbin or bobbin case drops.
Your bobbin test can have any of these results:
- Your bobbin is stuck with your thumb and index finger. No thread is coming out of the case. It means your tension is too tight. Your bobbin thread will not be able to lock together with your top thread.
- Your bobbin case almost drops to the soft surface you held it over means your tension is too loose. When your bobbin tension is too loose, you will see your bobbin thread on the top of your fabric.
- If your bobbin case drops one or two inches below your fingers, it means your bobbin thread has good tension. Your bobbin thread will lock equally with the top thread to make proper stitches on your fabric.
Now you already know how to check your bobbin tension for the front-loading bobbin. It is time you learn how to fix it if something is not in place.
When you have found out if your bobbin tension is too tight or too loose, you may start adjusting it to meet your goal. Outside your bobbin case, you will see a flat head screw and a Phillips screw. Do not turn the Phillips screw as it may damage the bobbin case, rendering it useless.
Use a small screwdriver to turn the flat head screw clockwise in tiny increments to tighten the tension. To loosen the bobbin tension, turn the screw counterclockwise or to the left. Test the tension between each adjustment of the screw by sewing on a sample fabric nearest to the one you will use on your sewing project.
- Top-loading or drop-in Bobbin
Checking the bobbin tension for the drop-in bobbin type is totally different from the front-loading bobbin type. Start by setting your top thread tension dial according to what you will use on your sewing project. Fixing your bobbin tension is done simultaneously by checking the tension.
Once your top thread tension is set, sew straight stitches on a scrap of fabric (like the one you will use for your sewing project). You will see what your stitches look like with the current bobbin tension. If bobbin thread shows on top of the fabric, the tension is too loose, but if you see a lot of the top thread underneath the fabric, the tension is too tight.
To take out the bobbin case for adjustment, you have to remove the throat plate also. Never adjust the bobbin tension while the bobbin case is still plugged in the machine. You can tighten your bobbin tension by turning the flat head screw to the right. By adjusting the screw to the left, you loosen the tension.
Keep turning the flat head screw until you find your top thread and bobbin thread’s right tension balance. Do not tamper on the Phillips screw as it will not help with tension issues and may damage your bobbin instead.
It is easy to adjust your bobbin tension, but it would be a lot easier sewing without tension issues. If you can avoid adjusting your bobbin tension, please do so. Sewing pros suggest on one bobbin case for regular sewing and another one you can adjust only when you need it.