Machine Stitching: Tension Troubleshooting Tips

Few machine stitching problems vex quilters as much as thread tension troubles. Skipped stitches, loops forming on the top or bottom of the stitch line, puckering always seem to arise at an inconvenient time. (Not that there’s a good time for a tension crisis.)

machine stitching trouble shooting tips

Sometimes problems with tension can be anticipated, such as when you’re stitching on slippery, thin fabric or thick or uneven textiles. But sometimes, tension issues just seem to “happen.” When they do, relax and try these trouble-shooting tips from machine quilting expert Susan Brubaker Knapp:

Tension Troubleshooting Tips

Machine stitching tension problems are tricky to resolve because there are so many variables. Here are some things to try:

1. Completely remove the top thread and the bobbin thread, and re-thread the machine. Always thread your machine with the presser foot up. It sounds too simple a solution to work, but sometimes that’s all it takes. 

2. Make sure the innards of your machine are clean and oiled (if recommended by your machine manufacturer). 

3. Change the bobbin thread. Try a different kind of thread (polyester or monofilament), or a finer (higher number) thread.

4. Try a different type or weight of top thread. Discard old, brittle thread. 

5. Use the correct spool pin. Cross-wound thread should be placed on a horizontal spool pin. Parallel-wound (also called “stacked”) thread should be placed on a vertical spool pin. 

6. Make sure your bobbin is wound correctly. It should be wound at medium speed, and, when done, should be firm and snug on the bobbin. 

machine stitching tension troubleshooting7. Seeing bobbin thread on the top? Bobbin tension could be too loose, or top thread tension could be too tight. Tighten bobbin tension first. If you have a Bernina, try threading it through the little hole in the bobbin case “finger” first. Turn the bobbin case screw clockwise to tighten. Move it a tiny amount at a time. (Caution: Always note the position of the bobbin case screw before you change it. You can make a drawing, take a digital photo, or mark it with a fine-tip permanent marker on the case itself. Some people prefer to purchase a second bobbin case for tension adjustments.) 

NOTE: I’ve had people tell me I should never, ever change my bobbin tension by messing with the screw. To them, I reply, “If you were never meant to change the bobbin tension, why did the manufacturer put that screw there?”

8. If problems persist on the top, loosen the top thread tension (move it to a lower number, one number at a time until the tension is right). 

9. Seeing top thread on the underside? The top thread tension could be too loose, or bobbin tension could be too tight. First, tighten the top thread tension (move it to a higher number, one number at a time). 

10. If problems persist on the underside, loosen bobbin tension. Turn the bobbin case screw counter-clockwise to loosen. (See cautions in tip 7.) machine stitching tension troubleshooting

Susan offers many more tips tricks, and advice on her video tutorials, Master Machine Stitching and Master Machine Quilting.

P.S. Do you have tension trouble-shooting advice? Share it below.


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19 thoughts on “Machine Stitching: Tension Troubleshooting Tips

  1. My father repaired sewing machines for years and he taught me to pre-check my bobbin tension with a simple test. With the bobbin threaded in the case, let it dangle by the thread and then give it a little bounce. If the tension is right for your thread, the bobbin and case will slip down the thread about a half an inch with each bounce. If it slides right through, the tension is too lose. If it doesn’t slide at all, it is too tight. I’ve always found that got me right to or very close to the right tension before beginning. As far as “never” adjusting the bobbin tension screw, that’s what it is there for, it is your tension adjustment in leiu of a knob.

  2. I work for a dealer who has been in business for over 50 years. While most of your suggestions are excellent, the one on bobbin adjustment is where we would differ. We suggest to the customer that they try to adjust their upper tension first. In non Bernina top loading machines, getting to the bobbin case is often tedious. One or two clicks, up or down on the upper tension dial or section of the machine, often does the trick. If it takes more than that, it may be worthwhile to adjust the bobbin tension. I change bobbin tension when needed, but it is not often the first step. My Brother works best with upper tension adjusted downward by two steps. In fact, Brother and Babylock upper level machines have the ability to do a systemwide adjustment of upper tension by the user through the settings screen.

  3. This is the kind of information I read and then promptly forget until late at night when I need it! Then I am frantically searching my owners manual and the internet. This article is much simpler and clearer than either of those. Thanks Susan for sharing your wisdom and thanks Vivika for passing it along!

  4. THANK YOU SO MUCH!!!! I am making purses working with 7 oz and 10 oz 100% cotton and/or duck cloth. I also paint the material and I am having so much trouble with the tension. I have been doing the exact opposite of everything here to solve the problem! I even printed this out. I, too, was told to NEVER mess with the tension set by the manufacture. In my mind I thought the same as you, why would they put a tension screw there??? However I DO change my needle constantly 🙂

    Thank you again! I may not be a very good quilter, but I have been sewing projects for 30 years, and I finally got a great fix for my tension problems besides considering throwing the machine out the window.

    Have a wonderful day, Rasz!

  5. Thank You so much for this article!!!!! Most of us have one machine that has to do multiple duties with multiple fabrics. Thus making tension issues an everyday struggle! My Great-Grandma (who taught me to sew) used to battle with her tension as well. She would refer to this problem as “boogered up”.

    I have printed out this helpful information & tacked it up next to my machine.

  6. Thanks for this list Vivika & also help from others – Here’s my problem – I’ve tried quite a few of these steps already but the borrowed machine I’m working on shows stitches on the top, I adjust, it sews well for awhile, then grabs the thread, the top thread spins off a bunch of thread which immediately makes a big mess underneath
    Will adjusting the bobbin tension deal with this ? What is happening to cause the “grabbing” action ?

  7. I am a thread painter, changing color and type often. I started using Superior Thread chart that lists thread type, bobbin thread recommendation, top tension as well as needle size AND the majority of my problems went away. Most all problems have been managed by adjusting top tension and needle size. Can’t emphasize enough the impact of needle type and size paired to thread type/size.

  8. After steps 1 and 2… CHANGE YOUR NEEDLE. Many times your problems will disappear with a new sharp needle, perhaps a better suited needle for your project. Dull needles can put burrs on your hook. I know from experience 🙁

  9. Thanks so much for this information. This has happened to me and I have sometimes worked for hours to fix the problem. I have even purchased new bobbin cases. I am printing this out to put in my sewing book for future reference.

  10. If the top thread is looping on the underside, check to make sure the presser foot is actually down. Tension disks only engage when the presser foot is down (which is why we’re told to thread the machine with the presser foot up), and with some machines/free-motion feet it’s easy to miss this since fabric slides easily under the free-motion foot even when it’s down.

  11. Cornellya Joss, I have had the same problem, always with horizontally wound “stacked” spools. I don’t know why it happens, but my solution is to drop the spool into an old Rx bottle and run the thread up through the small round end of a safety pin that I tape to the top right edge of the sewing machine, then through the usual thread guides. The bottle sits in the table to the right of the machine. Good luck…this problem is maddening, I know.

  12. Before you start adjusting the tensions, make sure your bobbin thread and top thread are the SAME thread, or at least the same weight (thickness).

  13. Before you start adjusting the tensions, make sure your bobbin thread and top thread are the SAME thread, or at least the same weight (thickness).