Fly little nestling – Ditching the Thread nests part 1

One of the most common issues that people bring machines to me for is tension.

The thing about it is that – in most cases – the tension issues are really not something that I need to address as a technician . Don’t get me wrong, there are some legitimate issues – mis-assembled tensioners or severely clogged up tensioners – to name a couple.

In the bulk of the cases though… well there’s no really nice way to say it – it’s more of an education opportunity than it is tune-up situation.

Many of us were taught in school not to ever touch the tension dial. In all honesty, this wasn’t because that dial was not supposed to be adjusted, it’s because your home economics teacher didn’t have time/want to reset the tension on all of the machines after each class. Unfortunately, in many cases, this wasn’t really explained as being the reason.

The fall out from that is that there are a lot of people out there that don’t think that their tension dials should be touched. The end result is that a lot of us are reluctant or even downright scared to touch that tension dial. I’ve talked a little about this in the past. [Fragile Tension / Bobbin Along]

Some of people I’ve met didn’t even know that there is such thing as bobbin thread tension.

Today I’m starting a series on some of the common scenarios that cause a poor stitching result.

  1. Thread Nests
  2. Pokies top
  3. Pokies Bottom
  4. Rail road tracks
  5. Eyelashing
  6. Tunneling
  7. Ruffling
  8. Thread breakage
  9. Loops
  10. Skipped Stitches

First off, it’s important to know that in many but not all cases, it is the top thread tension that will need to be addressed, but not always in the way that you think it needs to be.

Scenario #1: The dreaded thread nest.

We’ve all done it. We thread the machine up, put our work under the foot, start to sew. Suddenly we start to notice the machine starting to labor and the fabric stops feeding. It’s bunching up in the same spot and there are “crunchy” sounds. Many times the work can’t be removed and we start cutting threads -gently- out from under the fabric and above the needle plate. Often there are a lot of creative words uttered at significant volume at this point.

The bobbin thread has gone berserk and is making the nests.

Don’t believe this is a myth?

Try this: Don’t touch anything at the top of the machine – change the bobbin thread to a different color – same weight of thread and test sew again. Don’t worry, I’ll wait here while you try it. 😉

What happened? The nests are still forming and they’re in your needle thread color, right?


There are 7 reasons I can think of for this to happen, 3 of them are user error, one is a maintenance issue and 3 require repair or adjustment.
I’m going to list them in order of most common to least common (in my experience)

Today, we’ll cover the user fixable ones – and because this post is way longer than I’d intended – tomorrow we’ll cover the ones that may require intervention from your sewing machine technician (or that you can handle if you’re handy)

Category 1: User Fixable

Reason #1 The presser foot is not lowered. This is a common mistake especially when doing anything with a darning foot. Because the darning foot “floats” above the fabric part of the time, we tend for some reason to not notice that it’s still up after we put fabric under the foot, especially when we’re distracted momentarily by a quilt inspector or by chocolate. 😉

Here’s why this happens:
The presser foot lever does more than lower the presser foot to smash your fabric flat and help the feed dogs move it. The presser bar lever also actuates a “pin” that pushes the tension disks apart – releasing tension on the upper thread – thus making your work easier to remove.

When we leave the lever in the up position when we sew, there’s also no tension on the upper thread. It speeds off the spool and under the fabric faster than the speed of light and tries to knit your bobbin a sweater.

Unfortunately, if your sewing machine is anything like mine, it’s terrible at knitting and drops more stitches than I do when I knit.

Solution: Lower the presser foot.

Reason #2 – The machine is threaded wrong. The 2 most likely places for the machine to be threaded wrong are at the take-up lever and the tensioner. When this happens, tension always suffers.

Note: Some machines (the early Pfaff Quilt Expression and Select 4.0 machines come to mind) like to slip the thread from the take-up levers too. For the 2 machines I’ve mentioned here, your Pfaff dealer can get the parts and may do the upgrade at no charge, or they may choose to charge you, depending on many factors. I’m not currently aware of the part numbers for the upgraded parts, so I’m not able to do the repair. If anyone has the numbers and would like to supply them, I will find out if a non-Pfaff Dealer can get the parts.

The take-up lever is a spot to keep an eye on but the tensioner is typically a simple fix.

Always make sure that the thread is flossed into the tension disks. The disks can’t do their job if the thread is just laid on top of the disks, or worse yet – if the thread is not between the disks but behind or in front of them altogether. Some machines seem prone to this problem.

Not threaded into the disks:

See how the two threads are sitting around an inch away from each other as they enter and leave the tensioner? This thread is not between the disks, it’s just sitting against them. This will lead to thread nests.


Incorrect threading behind the tensioner

Most of the “exposed” tensioners like on a vintage machine can slip the thread behind the disks instead of between them. When that happens, there is little to no tension on your thread.

At first glance this looks right, the threads are closer together and they look like they’re in the tension disks. Look closely though and you’ll see that they’re behind the 3 tension disks in the photo. This will lead to thread nests.


Solution: Insert the thread firmly between the tension disks

Properly threaded – this is what an external tension assembly will typically look like. Notice that right to left, the thread naturally sits about a third of the way into the tension disks, and the thread guide sits out further on the right than the thread does.


I provided a little tip on making sure that threading the tensioner isn’t a source of problems in my Fragile tension post. It’s about 2 paragraphs below the video, in the lighter grey text.

Reason #3: The tension setting is way too low.

The tension dial or even on the electronic / computerized machines should usually be set pretty close to “middle” for most utility stitching (including the straight stitch we use for piecing.) This means that if your dial goes from 0 – 9, 3 – 5 on a properly adjusted tensioner should give you a balanced stitch. If your tensioner goes from -5 to +5 (like some of the Pfaff sergers), then 0 or “N” would be normal with a little adjustment needed higher or lower depending on the threads you’re using.

Note: For those with external tensioners – If you set your tension to a mid range then notice while sewing that it adjusts itself to a lower number, your tensioner needs the post that all the pieces ride on “adjusted”. Over time, the post tends to narrow at the end furthest from the machine and that resulting “cone” shape causes the tension to loosen with vibration. We’ll cover this in a later blog post.

One of the things that people who repair sewing machines and professional seamsters/seamstresses do is “read” the test sew. Here’s how we do it.

Consider the following example. (Ignore the 7 on top of the heart, it’s from the first demo I tried to do for you, but my 15-90 just wouldn’t misbehave enough, so we’re using a Pfaff 6122 for this demo.) On the second photo, I’ve flipped it, so it looks like the top photo, to make the comparison easier to see. The downside of course is that it flips the numbers backward as well.

  • You’ll notice that at 7, the top thread is pulling the bobbin thread to the top. This is top tension a little too tight.
  • At 5,the stitch is still a little biased toward the top thread.
  • By 3, the stitch is starting to reverse. We’re getting some top thread on the bottom and even the odd loop. This is about what I’d expect with this machine. Usually good tension is between 3.5 and 4 for this particular machine.
  • At 1, the stitches look fairly normal on the top, but if we flip the test sew over, we see noticeable loops on the back
  • At 0, we’re getting significant loops on the back, even though the stitches still look “normal” on the top. Additionally, we have eyelashing in the corners, and that was with low speed sewing. If I was actually doing some free motion sewing with my tensioner set this low (or another issue causing the same tension as a 0) this would be even worse.
  • Lastly, PU (which stands for Presser Up, rather than the original Foot Up, I’d been using…) shows a definite nest. I do believe that with more sewing at 0 we also would have seen a nest eventually.



Solution: Test sew it out to see what the best setting is and raise the upper thread tension on your machine!

Tomorrow we’ll cover 4 more reasons that thread nests happen. There are videos in tomorrow’s post, so I hope you’ll set aside a little time to watch if thread nests and tension in general have been a challenge for you.

Did any of this resolve an issue for you? Let me know below. I love to hear from you all and I try to respond to all comments.

17 thoughts on “Fly little nestling – Ditching the Thread nests part 1”

  1. Thanks for reason #2. I still don’t understand WHY it does it, but my 403 would let the thread OUT of the tensioner disks while it was running, leading to a god-awful bird’s nest as the top tension went away completely. It put the thread in between the OUTER two disks, problem solved. Now to check my timing again, as I just had a needle strike.

    1. You’re the second person recently who’s mentioned a 40X series machine un-threading itself at the tensioner. I’m at a bit of a loss as to how that’s possible if the machine is threaded right.

      If you come down from the top of the machine, left to right through the tension guide, under the tensioner (flossing it into the tensioner) then up through the thread take up spring and through the take up lever – in theory, it should be impossible for this to happen without the thread breaking. What are the specifics of how its happening?

  2. Sounds familiar. I had been doing free motion stitching with no pressure foot. It had been running fine but then it snagged as mentioned above but after removing thread and fabric the bobbin housing(? not sure of name) is now frozen. Any suggestions would be appreciated. As we live in Northern Ontario Canada with the nearest Urban Centre 5 hours away. Mine is a 411G. Thanks

  3. Yes, that is correct, just the pins now. I am using clear hockey stick tape to hold the plate in place right now. Tough tape and removes easily leaving no glue residue. Have a great night, thank you again, Linda

  4. Yippee!! The 411G manual is in my computer with all the instructions for the chain stitch. Thank you so much. Linda

  5. Okay tks, Lucky me, I definitely have the plates for the single and double to do the chain stitch, and I also have the plates to block the dog feeds to. Just got to get those special screws and some instructions on how to put them in. I guess I will just have to experiment to see how the chain stitch thingy works. I did locate a fellow on EBay that had made copies of the manual and it had 104 pages instead of the 100. He said it had instructions for the chain stitch. Wanted quite a price for the book and I asked if he would take a money order he did not reply. Maybe he was away for Christmas. I will dig out the machine tomorrow and write down those numbers and send them to you so you can have them on hand in case someone else needs them. Do you want pictures of them too. How do I attach them, maybe if you send me your email and I will send pictures and the numbers Tks for the info on the pins too. Linda

    1. I’m glad to hear you have the plate! They are rarer than gilded hen’s teeth! Don’t pay him for an expensive manual! I believe the ismacs copy has chaining in it. If it doesn’t, I can copy what’s in my 411G manual for you – it’s the same. For that matter, I think ismacs has the 411G manual up there too. If it’s not in either, let me know. Some of these eBay sellers make me nuts selling what’s in the public domain. As for the numbers, you can go ahead and post here or hit that contact button at the top of the screen. That will get to me.

      1. Sounds wonderful to me. I already downloaded the manual, but it did not have that one section on the chain stitch so I will try where you are suggesting, and I will post all the numbers for the plates and might as well post the ones for the feet too. Then it will all be there for anyone that needs them. Please let me know if you come across a set of those screws. But will tackle that tomorrow. Linda

        1. It’s pages 22 to 27 in the 411G manual at the ismacs link above. If you have any trouble with that let me know. I will let you know if I find a set of the pins. Have a good night. 🙂

  6. Your written and video info has helped so much. I had a 431G given to me. Someone had taken it apart and did not put it back together properly. The stitch selector on the right side would only go to H, and would not lock in A. The needle when set on B3 was off one number to the right. In other words to center the needle you had to set it on 2. The tension dial 0-9 would only go to 7 and that was so tight the thread was jammed between the little plates and would not move. Someone took a screwdriver to those pins that hold the stitch plates on. I would like to know if I can buy new ones. They are hooped. The one side is holding but I have scotch tape on the other side. Between your videos, your write-ups, and printing the book off I found on-line, hubby now has it purring like a kitten. All cams and built in stitches are working like they should. Can you tell me the number of the special plate I am to use to do the chain stitch, or show a picture of it. Everyone talks about it but do not give the number, or show a picture of it, and the book does not speak of it, (Unless I missed it in the book) I also need to know about buying those new pins for the stitch plate. This machine came with 7 plates,of which 2 are duplicates. Maybe one of the plates is that special plate for chain stitching, but with no instructions about it I am not even sure how to set it up to use it. I am going to be keeping a close watch on your web site and your Tube video’s. Love this machine!! Linda

    1. Hey Linda! I’m so glad that I’ve been able to help! I don’t actually have a 431G in my possession anymore BUT I do have access to it. What I would say is that the chaining plate can be recognize from the others because it has a small moving “finger” on the back of it. I don’t have that number at the moment. I -may- have posted it at one time on a thread on the during discussions there. If you don’t have the plate and haven’t found the number yet, let me know and I’ll try to remember to check the next time I’m in the same place as that machine. The pins are not something I’ve ever tried to buy (but yes, they’re often damaged or missing) – I was able to salvage them off a Touch and Sew machine, I think it was a 758 or some such? It looks like the part number for them is 174256 but I didn’t get a single hit on Google for them.

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