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.
- Thread Nests
- Pokies top
- Pokies Bottom
- Rail road tracks
- Thread breakage
- 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.