Q&A for How to Adjust the Tension on a Sewing Machine

I suggest you sew test stitches onto a piece of your fabric to see how the tension looks. That way, you'll know whether you need to make any adjustments before starting your project.

Have you oiled your machine? If not, remove the needle and foot. Take the bobbin housing apart, and remove the top cover where the light is, and brush it out with a small brush. Drip a few drops of machine oil onto a soft washcloth and wipe down the inside of the bobbin housing and the shafts in the top part. Put 2-3 drops of oil where specified in your manual. Run the machine at full speed for about 45 seconds. Put it all back together, and it should work great! Also, make sure you are using quality thread, as cheap thread will clog up your machine.

The presser foot must always be in the upper position when pulling the thread to attain an idea of the current tension. But, to fine tune the tension, you must place your project material under the presser foot, clamp it with the foot in the down position and test machine the fabric.

Every type of fabric uses different needle sizes and different tensions. With every project you sew, run a line of stitch in a piece of sample fabric. Doing this will enable you to adjust your tensions and get the the stitches even before you begin. A real time saver!

If the tension is correct, then it could be the slow rate of material feed under the presser foot. Also, check that the material being seamed is actually travelling together. If the bottom travels faster than the top and slip takes place, it will cause a cotton nest. You must help your machine's feed a little, looking to see that the material in front of the presser foot is smooth and perfectly flat with no waves of material. Lastly, check the presser foot's pressure. If it is too tight, the material may stall or not feed evenly. Again, if this happens, it will cotton nest.

There are a number of reasons for thread-breaking. One is cheap cotton that breaks apart as it is pulled through the machine, by losing its outer strands. It then either bunches or simply becomes so weak, it snaps. Ensure that the tension is not too high for the cotton to survive. A machine will sew perfectly with man-made polyester, which is very strong, but won't handle a weaker cotton, such as pure cotton. Also, cotton tends to differ in thickness in places and bunches up in the tensioner. You may have a battle on your hands if the tension continually varies, as can happen with cheap cottons. Lastly, before making adjustments, ensure that your machine is clean.

The tension is off. Turn the tension knob a little at a time. You may need one or two spring tensions for your needle thread.

The tension is unbalanced. Adjust the wheel that the thread runs through, it usually has numbers on it.

Maybe your thread has ran out. Check to see if there is thread in the bobbin and spool.

You probably pulled too much thread out, so maybe pull some back in by rewinding the bobbin and the spool so there isn't too much thread hanging out.

This could be tough one to answer as there are so many variables. The tensioner is set to a point where the stitching, top and bottom, meets in the center of the material you're sewing. If you are sewing a delicate material, you will need a thinner needle to prevent damaging it, whereas stronger materials, like denim, require a thicker, tougher needle to do the job without breaking. Polyester is very strong, smooth, and consistent, and is considered a general purpose sewing cotton. Once you set up your machine for polyester, it will do an amazing range of materials without further adjustment. If the stitching looks good and is even on both sides, then leave the adjustments alone and be happy.

I would suggest renewing the needle and ensuring that the machine is spotlessly clean, especially the tensioner. Make sure that you have threaded it correctly too.

Usually the flat surface of the top end of the needle goes away from the front of the machine.

Before a needle breaks, it bends, so firstly you must find out why it is being bent. Check the presser foot for positioning and ensure that your swing needle setting AND the presser foot being used are compatible. You can be the cause of the needle breaking by the way you manage the material being sewn. If you are sewing thick or multilayered materials and having to pull them under the presser foot, you will bend the needle. It will miss the hole and strike the plate, bending and breaking in the process. Assist a machine -- don't take it by the scruff of the neck and pull at the material being sewn. Lastly, it may be out of sync and in need of professional repair.

It sounds as though you have been unfortunate enough to unscrew it completely. This should not be possible, but it does happen from time to time. The spring inside the tensioner causes its internals to fly apart, the threaded portion is lost to the nut that screws onto it and it goes around and around. A handyman may be able to fix it, but the best thing would be to take it to an expert in a shop.

Little or no tension in the top thread can cause this. Try increasing top tension until you get the correct "yup of war" perfect stitch.

The timing is off on the bobbin, so the top thread is not being looped around the bobbin. Adjust the timing.

Some machines have a button that allows the machine to sew in reverse. Check that setting on your machine.

Most sewing machines have a stir adjuster. You need to choose a stitch that is moved over to the left or right, so it no longer hits your foot. If you don’t have an adjuster, you need to put on a different foot.

This depends on whether you're sewing with a vintage machine or a modern one. Modern machine: Have you just filled a bobbin and forgotten to reset the button/switch back to sewing? Vintage machine: Check the drive belt tension, it's very likely come loose, if so then adjust to tighten it.