The loosest thread – Those pesky thread nests

Some of the most common sewing machine issues I hear are:

  • “The bobbin thread is bunching up around the bobbin”,
  • “I have loops under the fabric”,
  • “It looks great on the top but the bottom looks awful!”,
  • “No matter how high I turn the tension on my bobbin, I still get a mess on the bottom side of the fabric!”,
  • “I keep lowering the upper tension but I still get loops underneath!”
  • “It’s the tension”
  • or something similar.

Something like this:

Top side of the fabric. Doesn’t look too bad.

Well that doesn’t look so bad, right? Until we turn it over…

Bottom of the fabric. This is the beginnings of a thread nest. About all that the 411G wanted to commit to today.

Ugh. ( With certain machines this is often worse – full on nests.  I couldn’t for the life of me make this 411G make the huge nests that were my constant companion with my first sewing machine.  See the end of the post for how far I went to get nests for you.)

In fact, sometimes you’ll even get extra thread wrapped up around the bobbin case and hook (Note the position of the needle.  With it all the way up, there shouldn’t be anything other than the bobbin thread showing in the bobbin area):

Bobbin thread plus friends?

I’ve talked about this before but I think it sometimes gets lost in the longer posts so I’m making it its own post and expanding on it some today because I’ve had a LOT of these comments/questions lately.

Often when I tell people this is more likely to be the top thread too loose, I get comments like, “uh, no it’s not”, “are you sure?”, and my personal favorite, “I’ve been sewing for longer than you’ve been alive, I know what’s wrong with my machine…” (yes, I’ve had that one in real life.)

So, today I’m going to prove it – with a little help from you of course, since I can’t lay hands on your machine.

When this happens – don’t re-thread your machine yet.  Yes, I know that this is the conventional wisdom but we’re testing/proving something here.  Instead, pop your bobbin out and change it out for a bobbin with a different and contrasting color of thread.  Clear your thread jam if you need (but without re-threading the upper thread path except for the needle if your top thread broke), put the fabric back under the foot and sew for a short stretch.  The same symptoms will likely occur.

Change only the bobbin thread color for this test

Now pull your fabric out and look at the backside.  Which color is the thread mess in?

Now we see that the top thread has been causing all of the issues.

Now you might be tempted to say “See? The bobbin thread is a mess too!”  It’s not the biggest offender though, is it? That bobbin thread would be well controlled if the top thread was properly tensioned.

Poor Bob(bin) – He always gets the blame but it’s rarely his fault!

This is largely because of how a stitch is made.  In reality, the bobbin thread doesn’t really do much other than get in the way of the top thread traveling around the bobbin and get twisted into making the stitch.  This gif (should it actually move for you – click on it if it doesn’t so it opens in another window) shows how the stitch is made.

This image should be animated. If it’s not, click on it to open it in another window and it will move.

Seriously.  Pull your slide plate back, or pop the little bobbin cover and watch your machine make a stitch while it’s threaded with 2 different colors – hold your tails loosely when you do it though.  Removing the throat plate is probably unnecessary.  I only did it for clarity in the next few photos.  This is the same for a vertical or a horizontal bobbin setup.  As you’ll see, the bobbin thread isn’t really moving other than from friction of the needle thread passing over it, until the stitch is almost finished.

Beginning of the stitch
Middle of the stitch
Nearing the end of the stitch. Note the loop forming around the bobbin thread under the feed dogs.

In fact, that bobbin thread getting in the way is what causes this twist, which is what tells you a machine can make a stitch, even without putting fabric under the presser foot.  I rarely take fabric with me anymore – just needles and thread if I’m trying out a machine.  If I see this twist, I know it’s got most of its stitch mechanism intact enough to be viable.  If it doesn’t, it warrants a little more investigation before I choose to hand over any cash or to walk away.

The first day I truly saw how a machine made a stitch, my sewing life changed forever.  My sewing machine went from a magical and somewhat intimidating “black box” to something I could understand and reason my way through.

OK, so now that you know where to start looking – evaluate the upper thread path – and find the issue.  When you’ve done this, re-thread the machine to fix the issue.  Doing this will help you see where an issue likes to happen and watch for it in the future.

Note: In fairly rare circumstances, a minor version of this looping underneath can occur if the bobbin thread is not properly threaded into the tension spring but it’s very uncommon compared to the upper thread being routed wrong.   This is because there’s not nearly as much pull being exerted on the bobbin thread at any given point in the stitch process as there is on the needle thread so way less bobbin thread will ever be in play while the stitch is being made.

It’s also worth mentioning that typically a problem that shows up on the bottom is from the top thread and a problem that shows up on the top is from the bottom thread – unless one or the other thread is snagged on something.

This is how far I went to get the 411G to misbehave for you today.  I actually disassembled the tensioner to the point where no tension would be applied and it still sewed as well as you saw in the photos.  All tension control would have been provided by pre (before the tensioner) and post (after the tensioner) tension only. There’s a reason I love these vintage machines. 🙂

Tensioner – under no tension at all.

Boy it seems like I talk about tension a lot.  Ever wonder if there might be some stress in my life? 😉

What else would you like to read about? I’m looking for suggestions for future topics.  More on the spinning progress I’ve been making?  The woodworking progress? More techniques?  Long Arm stuff?  Heck, maybe I’ll even get back into the darkroom sometime soon.  Let me hear it!  Comment below or drop me an email with the contact link above – just know I might not respond quickly or I may just post about your topic if it was a topic suggestion only.

Today’s post title comes from Minnie Driver.  Yes, that Minnie Driver.  She put out an album in 2007 and Mockingbird was the first song I heard from it.  I’ve always liked the imagery in the song.  The title comes from this verse:

The color of desire is a wretched blue
It burns just like the center of a flame
It pulls the loosest thread inside your mind
It burns everything, but it calls you out by name

19 thoughts on “The loosest thread – Those pesky thread nests”

  1. I stumbled on this thread by accident. I have an intermittent problem with my 401a. It will be sewing along just fine for a while. Then, for some reason I don’t understand, I’ll get a huge thread nest that locks up the machine. There is so much thread knotted up under the needleplate that you have to cut the knot out with a seam ripper. It’s wrapped around the area under the needle multiple times. Since I have to cut it out, I can’t find where or why it’s caught.

    It was suggested that I needed to clean the bobbin area again. This time, I removed the bobbin case and cleaned it with about 20 q-tips and some sewing machine oil (chunks of gunk came out). It improved significantly, but didn’t stop all together. Now, instead of 2 or 3 nests per day, I get one every week or so.

    1. If you’ve had a 2100% increase in the usability of the machine, I would think that you’re looking in the right place. 20 q-tips is a whole lot of required cleaning. If it needed that much, it was far overdue. If you’re actually sewing that much, try cleaning the bobbin area more often and see if you can stay ahead of the issue, rather than being reactive. Singer usually recommended every 8 hours of sewing for oiling. The bobbin area should be cleaned even more often than it’s oiled. Try every second bobbin then adjust from there if needed.

      1. Thanks. When I acquired this machine, it was full of dried up oil. Many of it’s functions did not work. From observation, I deduced that it had been used regularly and oiled frequently before it was left untouched, in a storeroom for years. I’m sure that another cleaning is in order.

        Thanks again.

        1. You’re welcome. I hope it helps. If after regular cleaning and oiling, it’s still a problem then maybe there’s something else to look at but for now it seems like there was little point getting in deeper if it could be solved by doing more of what you’ve been doing. Good luck!

  2. Thanks for your lovely article. I just went to look at a Pfaff 1222 and the man was all about showing me every nook and cranny about the machine. He wanted me to be happy with it. He ran it but it nested up; he started for the bobbin area. I stopped him and said, “Let’s try adjusting the tension.” Bingo! One little twist and it sewed with perfect tension. Needless to say I snapped that puppy up. It was a good price and had the case, sewing table, pedal and all accessories. It has been my dream machine for 4 years and I’m sew glad I knew about the tension trick and nests!! Thank you.

    1. Great score!! I’m so glad I was able to help! Those tables especially are tough to come by. I’m about to order an acrylic table for a couple of those same machines.

  3. I have a curious occasional thread nest on my 401a! It’s going along stitching fine, beautiful stitches, then bam all of a sudden the top thread is pulled under the plate. The bobbin is set correctly, the upper threading is correct tension seems fine, my two observations are that the bobbin case even when set correctly seems to be loose, moves a lot more than my 503.. and the other is that the thread seems to suddenly stop smoothly feeding off the thread spool, no snags on the spool, tried several different types of thread. I’m usually a good thread nest problem solver (teach sewing to teenagers!) but I’m mystified by the intermittent nature of these. Is there a way to tighten the fit of the bobbin case? Do I have a problem with one of the springs in the tensioner, It’s all clean and reassembled correctly. Thanks for all your great videos, I have fixed every issue I’ve had so far with my rescued 237, 503 and 201-2 from your tutorials. Hoping you can diagnose this one!

    1. That seems like it might be a burr that’s grabbing the top thread. Since the bobbin case seems to move a lot, investigate especially under it where the thread is passing but throughout the entire thread path too. Nylons or cotton balls can help find burrs. If you drag either across parts, they’ll snag on anything that’s not really smooth. The bobbin case shouldn’t be tight – the thread can’t run where it needs to if it is.

      Not feeding smoothly is a little too broad for me to help much. The easiest way to figure out where to start troubleshooting is usually to stop immediately, then tug the thread gently on the right side of the tensioner and see if it’s bound up. If not, tug the left. Usually only one will be bound and that will help you know where to start. I’d look for a burr or worn guide there too.

      1. I looked and felt for a burr, but I will try the cotton bud trick! Tried to post a pic of where the top thread ends up kind of under the bar under the feed dogs but can’t seem to post it. I’ve put a new tension spring in the tensioner but it still happens, it’s almost like the thread suddenly jumps off the spool having been invisibly stuck! The same spools work fine on my 201-2 and my 15-91. I use a thread stand on my featherweight, maybe I should do that on the 401. Anybody tried that? it happens more often with cross wound spools, I must admit I’m almost ready to give up on this machine and sell it maybe someone else will have better luck 😥 Thanks Tammi. I’ll try both your tips before I give up.

        1. I think I know where you’re getting hung up – it usually comes down to thread delivery (tension) and/or burrs when it happens. Burrs can often be that hard to find. Usually they’re somewhere you don’t expect them too. Cross-wound thread often jumps – it’s not really meant to be on the spool pins of these machines. If the thread stand eliminates the problem, you know what it was. Some pins seem to make it worse – I think the nylon ones probably flex more and compound the issue. Yeah, wordpress isn’t very friendly about photos in comments.

          1. I went over the whole machine today with a cotton bud and nothing, then taking the needle plate off for the hundredth time I noticed that on the underside where the needle goes thru there is a little piece carved away, kind of a thread guide I guess, that had a slightly sharp edge, I got out the 00 steel wool, smoothed it down, same on the bobbin case for good measure, cleaned under the case again, lastly ordered a thread stand, although since then I’ve seen your paper clip idea which is awesome!! I will let you know how it goes, will test in the next few days. Thanks again for the pointers 🙂

            1. Throat plates are a really common place for burrs. A good needle strike can do all sorts of calamity. I’m glad you found that one. I hope it was the only one!

  4. Very good thread but I have another new twist for you. My 1948 Singer 99 was sewing along nice then I went to a slightly heavier thread then all h”/$ broke loose. I tried everything and all I had was thread jams. The lighter thread worked ok but the heavier threat wouldn’t work. I took off the needle plate and watched. When the upper thread passed under the bobbin case arm it caught. When the lighter thread passed under the arm the bobbin case lifted slightly and let the thread out. I then put a bobbin case from a newer machine in and it sewed perfectly. Comparing the two cases the long thin arm on the good one curved up with about .050 inch gap. The arm on the bad one was bent down. Simple fix … bend it up…easy. SNAP!!! It doesn’t bend. I silver soldered it back on. After smoothing and polishing it worked perfectly. The problem was a bent arm on the bobbin case. it’s something you don’t see every day.

    1. Good point. I did assume that there were no damaged part in this post.

      Yeah, most of the time things that will bend once will break the second time they’re bent. 🙁 I’d be interested to hear how your fix holds up long term. I’d think it should be fine. I’d be curious to know how it got bent in the first place.

    1. Sounds good! I’ll blog as the urge takes me. I have been doing a lot of spinning and some woodworking to keep the older spinning wheels going. 🙂 Maybe I’ll put up some details about that and the new class I’m developing .

  5. This happened to me today – again. Hope it happens tomorrow so I can try your suggestion. And yes, I rethreaded the top thread. Keep these great tips,coming, please!

    1. Ha! You might be the only person I’ve ever heard of asking for their machine to make nests – but I hope it helps you out. 🙂

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