Thread Tension Adjustment Explained

Thread Tension Adjustment Explained

This is an industrial sewing machine
tensioner. Does the thought of adjusting your thread tension give you a tension
headache? In this video I’ll give examples of good tension and bad tension
and I’ll try to take some of the stress out of thread tension so be sure to pay
attention. Sewing has always been about the amount of tension that gets put on the thread in order to make a stitch and when sewing by hand you often
see this type of a movement this this testing your tension to make sure you
get the right amount of pressure on the thread so that the stitch is formed and
just tight enough, you don’t want it too tight, you don’t want it too loose so you
often see this sort of testing the thread tension and so the thread tension
when you’re sewing by hand is completely intuitive and you don’t really think of
it as thread tension but this sort of judgment call that you do when you’re hand stitching has to be dialed into a machine somehow that’s where the thread tensioner comes in most of your sewing machines are of the lock stitch variety.
For a sewing machine to make a lock stitch it uses two threads, one thread is
on the bobbin and the other thread comes from a spool and so this top thread and
this bottom thread are used together to make a lock stitch setting thread
tensions between the top and the bottom it’s a balancing act and you want those to
meet in the middle so in this figure you can see the top thread and the bottom
thread meet halfway in the middle in this next figure we see an example of
the top tension being too tight pulling the bottom thread all the way up to the
top and finally in figure three an example of the top tension being too loose and
so in this example the machine is unable to pull the bottom thread up into the
fabric so what we’re looking for is that Goldilocks adjustment where the machine
can pull the bottom thread up into the fabric half way, not too tight not too
loose so when we talk about thread tension 90 to 95 percent of all our
adjustments will be done right here at the upper thread tensioner, will just say
thread tensioner. So one thing you need to know is righty tighty lefty loosey so
if we turn it to the right we tighten the tension if we turn to the left we
loosen the tension righty tighty lefty loosey so it’s pretty easy to make the
adjustments a lot of times you can make adjustments on the fly based on what
you’re seeing in your sewing project when you change threads when you change sewing projects you may need to tweak this some different thread sizes
different project thicknesses and consistencies can cause you to need to
change thread tension and the easiest way to do it is right here so let’s look
at some different stitches so that we know when that we need to make an
adjustment here I have two colors of thread I’ve got white thread in the
bottom in the top I’ve got a black thread so what I’m going to do now is
loosen this top tension and make it way too loose this is a common problem and
what it causes is what people describe as a rat’s nest so if you have a rat’s
nest your problem may be a thread tension that’s too loose like this that doesn’t sound very good now and now my work is stuck in the
machine so we’ve definitely got a problem here so a seemingly simple
adjustment on this has caused my machine to lock up and I’ve caused myself quite
a problem but I’m gonna get to the bottom of it and then I’ll let you see
what it looks like all right classic rat’s nest let’s look at the top
here we are on the top everything looks good but in the bottom we’ve got all
this black thread all this top thread is on the bottom of the work so again
blacks on top whites on bottom but we’ve got all this black thread on the bottom
and we’ve got great big loops of it so what’s happening here is the sewing
machine makes loops to form the stitch when you have the proper tension the
take-up lever pulls that thread back up when you don’t have enough tension that
take-up lever moves up and nothing happens that loop stays down in the
bottom of the machine underneath the fabric like this and causes all sorts of
havoc so if you see this that rat’s nest then your top tension is probably too
loose and your work is going to be stuck in the machine and you may think that
there’s something horribly wrong with your machine in fact it’s just a tension
issue so I cut all this off just so it doesn’t
cause me any more issues let’s see if we can get this a little less messed up all
right now at least we don’t have a rat’s nest but you can see some black thread
within the stitch if the bottom has too much tension or the top not enough then
the top thread shows on the bottom so that tells me the top tension is not
tight enough rat’s nest way too loose black threads on the bottom just
slightly loose so now I can make adjustments in the quarter half-turn
range make a half turn and try again see where you’re at all right now I’m not
seeing any black thread on the bottom and there’s no no white thread on the
top so I’m back in business let’s just keep going let’s tighten it
up three half turns and see what happens okay now I’m starting to see some white
thread in the top let’s tighten it up just a little bit more see if we can
make this even worse alright now we’ve got a stitch that’s good and out of out
of adjustment all kinds of white showing up on the top so the bottom looks good
what’s happening is that the top thread is so tight that it’s pulling that
bottom thread to the top now if I grab this top thread and pull on it in effect
putting too much tension on the top thread you can see that the bottom
thread is pulled to the top it’s like a tug-of-war between the bottom thread and
the top thread and right now on this line the top thread is is winning we
want the top thread and the bottom thread to be equally matched and meeting
in the middle so when this is the case you want to loosen your top tension
a little more all right so I’ve got it back into yeah there’s no black on the
bottom there’s no white on the top so now the top thread and the bottom thread
are meeting somewhere in the middle of this thickness of the project there’s a
top tensioner and there’s a bottom tensioner the old wisdom has it that you
should never touch the bottom tension and only the top tension but if that
were true why would there be a tensioner on the bottom it is true that typically
most of your tension adjustments can be handled here on the top tensioner but
there are cases when the bottom tensioner does need to be adjusted some
of those cases might include if you go from a very small thread to a very large
thread the tensioner is basically a clearance and so that bigger thread is
going to not fit through that clearance quite as easily and so you might
actually need to loosen the tension in general the bottom tension should feel
pretty light so here we are at the bobbin hook and case the bobbin fits
inside the case the case has the tension adjustment now right here you can see
there’s two screws there’s this back one and there’s this front one the back one
just holds the spring in place the front one is the adjustment screw maybe right
there you can see where the thread comes out from underneath that leaf spring tension adjustment screw is tightened it
flies greater pressure on the leaf spring increasing the lower thread
tension conversely if I loosen this screw it
releases some pressure on the this leaf spring reducing bottom thread tension
this is awful hard to see let’s try something easier here’s a home machine
bobbin case so here’s where the thread comes out from underneath that spring
the screw farthest away from the thread deployment is the screw that holds on
the spring this screw closest to the thread adjusts the spring so as I
tighten this down it increases tension on the spring and that increases the
tension required for the machine to pull the thread out these adjustments are
quarter to 1/8 of a turn at a time these are very small parts you need the proper
tools and care needs to be taken so as to not lose the items or damaged them
thanks a lot for watching my video I’ve got all kinds of sewing machine videos
and sewing projects so if you’re not a subscriber be sure and subscribe to my
channel I really appreciate it

64 Replies to “Thread Tension Adjustment Explained”

  1. Nice video as always. Good, simple but, very accurate explanation of thread tension regulation. Thanks again!

  2. Alex, great video. How about one on common sewing machine issues. My juki 1541 is shredding thread. I was hoping it was tension or a needle but no. Your videos are great as I'm teaching myself about these machines.

  3. Great video! Great camera work as always. But what I was really hoping you would explain is how one might know when tension was completely balanced, but either too high or too low. In other words, what happens when you back off the bobbin case tension a lot, and back off the top tension an equal amount? Or crank both up? How does that affect the result?

  4. How do you select the appropriate needle sizing for your thread/material?

    Getting my tension right is a headache for me when hemming jeans. It may be due to incorrect tension, but maybe also due to inappropriate needle size. I'm guessing the eye isn't wide enough for the thick thread I'm using. Regardless, I've wasted lots of time and had to deal with a lot of rat's/bird's nests.

  5. Hi Alexander. Thanks for another very helpful video. I appreciate all of your videos. You are down to earth 🌍 🌎 🌏 , relaxed, and always helpful to me. I have to say your videos are becoming more and more professional as you are increasingly relaxed and now a pro making videos to share all your knowledge. You are appreciated more than you realize.
    BTW, I’m still looking for the ideal trip feed « industrial » sewing machine to serve as my work-horse machine, to do everything from thick denim seams and leather to typical piecing of quilting cotton. It seems the more I read and watch various people like yourself, the more confused I get. I know about the two types of motors, the Servo motor and a usual type of motor like the one you use here in this video and that is used in most domestic sewing machines. Sorry, but I’m forgetting the correct terminology right now. I’m having difficulty finding a shop where I can try using both or several types of machines and motors, so I can compare them side-by-side. Nevertheless, your videos help me learn and see clearly through the maze of what machines are available in the market. One day, I’ll find the right person and the right shop where I can effectively work with someone willing to spend a little time with me using various machines. Thanks for all that you’ve taught me, even though I know I sound a bit foggy this morning. I like the Juki and Consew machines; in general, would you recommend one make over the other? I like the idea of having a quiet, economically efficient Servo motor under the table with the machine built into a table. If you know a source where I could find these machines, or other similar ones, I’d appreciate your advice, since I always value your input. Have a great day! 🙏

  6. Thanks AD – Man I hate those dreaded 'rats nests' especially in my 211 – with the notch in the bobbin case that rests in the bottom needle plate. I see you are proficient at removing the plate to release the rats nest. I usually try to carefully dig/cut it out from the bottom. Removing the plate is usually the last resort but occasionally necessary if not caught soon enough. I love your wit – great tension tutorial.

  7. I got my 201-2 bobbin tension in the ballpark with a one ounce weight tied to the bobbin thread. Hold the bobbin/case in the air with the weight tied to the thread and the thread should basically just start to thread off the bobbin with a little shake of the bobbin. This seemed to work well for me at least getting the bobbin tension in the ballpark for the types of thread I use which is mostly #69 on my 201. Great video once Alexander, thanks for sharing your knowledge.

  8. Thanks for this excellent tutorial. Your diction is great and camera work is fantastic.

    I was struggling with rats nesting of the top thread yesterday on my home machine (Singer 500J) while topstitching with thick thread (Tex 90) on cotton canvas shorts. I had regular all purpose poly thread in the bobbin.

    I think it took me a while to work out all the issues.

    The needle was a jeans type size 100. It might have been still too small for that thread. I did not have a size 120 to try nor a topstiching needle type. Mea culpa on that one.

    The bobbin tension had gotten loose somehow. I fixed that using a 1 once weight to calibrate the bobbin. It did help.

    The top tension adjustment is still very sensitive. Just moving from 2 to 3 on the dial would result in too much tension. I have not had success taking this tensioning unit apart to clean yet (the dial thumb wheel will not come out) but I will try passing a thread with little knots in it to check for the presence of lint.

    It might be that I was pushing the limits of my machine too. I do not have an industrial size straight sewing machine and that could be helpful for that size of thread. I am going to make some jeans pants and jackets and will see how it all goes.


  9. Thank you for watching my video and for all the kind and supportive comments. You are all part of such a wonderful community.

  10. Thank you for taking the time to show the full range of situations—from rat’s nest to home-machine bottom tension (out of the machine). Your explanations are very helpful, as well as empathetic (eg, “you might be thinking there is something horribly wrong with your machine, but…”).

  11. I recently bought a serger and at the end gave it back because I could not obtain a result….but maybe it was a defectuous one.

  12. I am planning to do my car fabric seats reupholsterd with leather but the question is will my Singer 974 do the job ??? I dont have the needles and threads and the tools yet for the job i dont want to order them till i make sure that my machine will handle it …

  13. Would like to see you do a further addemdum talking about overall combined tension, how it can cause problems like pucker or just not tight enough seams the other way and how the sweet spot in the middle is acheived. just food for another great video some day…

  14. Thank you so much! My machine has been in the closet forever because the thread knotted up under the fabric. I am very happy to see this video and you explained it so well! Thanks again!

  15. Just excellent. I haven’t seen a video before that has discussed this issue so clearly as you have. I would love you to explain the presser foot pressure adjustment. How to adjust etc for different fabrics and troubleshooting. Thank you so much.

  16. Not being creepy….Has anyone ever seen this mans face? I love his work and what he's doing with sewing for men but seriously…Not seeing his face is like the Wilson character on Home Improvement.

  17. Perhaps you can help me. I just subscribed to your channel and I find it very helpful. I have an artisan industrial sewing machine and I can sew two pieces of 6' long Sunbrella together and the bottom piece comes out 1/2" shorter than the top. I adjusted the feed dogs but getting similar results. Any suggestions? It doesn't affect small projects but 15-20' is causing a big problem. I also have a big Juki 2 needle doing similar things but not as bad.

  18. Thank you! V V informative, v clearly n neatly explained,upto the point n the best of all no irritating music or distractions. I was struggling with this for a long this is going to be of great help to me. Keep going….

  19. I'm trying to stitch 2 – 3 layers of Sunbrella canvas on a Pfaff 1245 using 138 thd. and 140 needle
    I can't keep the bottom thread from pulling up to the top.

    Even when I reduce the top thread tension to the point of rat nesting the bottom thread knot clearly shows on top.

    I've adjusted bottom thread tension to max on the bobbin case. Still seems kind of loose but I have nothing to compare it to.
    I have ordered a new bobbin case hoping that is the culprit but this one seems fine.

    I sure could use some help with this one.

  20. Thanks Alexander, would you do a video or explain why sometimes my thread unravels and knots up before it goes through the eye of the needle ?     J K

  21. Hey I noticed that you always pull that top tag line when you start to sew. What does that do exactly? Sorry for the noob question.

  22. Love the Videos. The Sewing Machine Industry basically failed to inform clients about there Products. We only had the Manual Books which was/still Fantastic. The Illustrations are worldclass but this kind of Videos makes it much easier to understand.

  23. Thank you. It’s very helpful. I really learned a lot about thread tension. So far you are the best of all I have seen. Thank you again.

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