Tension Problems? How to Adjust Bobbin Tension on your Side Loading Sewing Machine

Do you know how to set the tension on your bobbin? We all know there's a tension dial on the front of the machine that controls the needle thread tension, but what about when the bobbin tension is the issue? There are times when you'll need to adjust your bobbin tension, and a lot of manuals simply make no mention of this setting.

That is why today I'm going to talk about side-loading bobbins where the bobbin goes into a silver bobbin case like this. I'm talking about machines that open out like this and have a little door where the bobbin case is housed. When you pull out the bobbin case, inside you'll see the bobbin. Did you know you could adjust the tension on this bobbin case? You can. Here's how...

There are two screws on the bobbin case. Normally one screw will have a halo around it, or be bigger, and it'll usually be the one that's closer to the hole where the thread comes out. We're not looking for the screw that just holds the bracket on. This possibly bigger, possibly halo'd screw close to the hole is the one you can adjust.

Why would you need to adjust the tension of the bobbin case?
Over time, sometimes the vibrations of the machine can cause that screw to become loose. I've seen times where it got tighter somehow, too. We just need to make sure that it's where it needs to be.

A lot of times, if your machine's not producing a good stitch, it's because the bobbin thread is just not under the right tension. The tension needs to be balanced between the bobbin thread and the needle thread. We need to make sure they're both at the right tension, working together.

How do we check the tension on the bobbin case? There is something called a Towa gauge, and it measures how much tension your thread is under. But, I've never used one of those, and I'm going to show you how to do it without it. For most machines, this is what you want this to look like.

We're going to do a hand and gravity test. You place the bobin in your hand, and then when you pull up on the thread, it should not leave your hand, or if so, just barely. You want it right on that edge. So, see the two screws? Again, you're going to take that screw and tighten it or loosen it in very minute amounts until you reach the point where it's right on the edge of not leaving your hand when you pull.

Each machine might recommend just a teeny bit different amount of tension. Most machines don't mention it at all, but for example, this Pfaff Creative 7570 said in the machine something that's slightly different from what I normally do. They say that it should come up, but with each jerk of the hand, it should fall a little bit. That's a little, tiny bit different from what I normally do. But, as long as it's in balance with the needle thread, that will certainly be fine.

Let's go ahead and get the screwdriver and make some adjustments.  I'll show you how it affects the bobbin. First put the bobbin in the case.  Here is a refresher on how to put your newly wound bobbin into your bobbin case: Hold the bobbin case on its side, in your palm, with the open side to the right. Now, take your bobbin and make sure that you're holding it in such a way that the thread is going away from you, up over the bobbin, and to the back, [see video]. Not where it's coming towards you up over the top of the bobbin. Hold it with the thread going up over and away from you. Now put that into the bobbin case like that. Then take the thread tail and pull it through that slash opening on the bobbin case. Then, continue to pull it until it clicks into that smaller opening.

Now, let's check the tension. If I put this on my hand and I pull up, it's not leaving my hand. That means it's not too tight, but there's a small chance it's a little too loose. So, let's adjust this. We're going to go to that larger of the two screws and take a screwdriver and make a very minute turn. I'm talking like maybe one quarter of a rotation and I've tightened that to the right. Now, let's try. If I hold this in my hand, look, it doesn't leave my hand. That means that's a little too tight.

Therefore, I'm going to now turn it back about 1/8 of a rotation to the left, to loosen it just a tiny bit. Remember, we want it right on the cusp.

Let's try again with that new adjustment.

Okay, it's leaving my hand. What I've always done if not specified, is set the tension such that the bobbin case releases the thread and does not leave my hand. However, this particular machine's manual said that it should dangle a little and then with each jerk upward it should drop a little. So that's what we have here. That's what this Pfaff recommends. For my other machines I would go a teeny bit looser, but that's what this Pfaff recommends, so that's going to be the starting point we use for this machine. But again, even if it was a little tiny bit looser, even if you didn't know where to put it, (because most machine manuals don't tell you), it's okay! Because you're going to start there and then find a balance with the needle thread.  If you have it pretty close to what I just showed you there. You need to either tighten it enough that it's loose enough to not leave your hand, or if it does, it's just barely, and you can still make it drop with upward motions as shown in the Pfaff diagram.

I loosened it a tiny bit and there now it's flowing freely, and now then the tension is right on that edge. That's the amount of tension that it needs. Right there, dropping when I jerk it. Perfect. Now this is ready to put back in the machine and sew.

---------------------------------
Let's try another machine. This is my little Kenmore 385 model. I'm just going to first take off the compartment. Inside this door is the bobbin case. Pull that out. Inside that bobbin case is our bobbin.

Need a more complete walk through video for threading and setting up the Kenmore 385? Watch it here:

Kenmore 385 sewing machine? Let's thread it, wind a bobbin, and sew!

Let's check this bobbin tension. If I place it in my hand and pull up, it does not leave my hand. And when I shake it, it doesn't come down at all. That's probably a little on the tight side. On this bobbin case, you can see I only have one screw. This shows that all the bobbin cases are a little bit different, but not by much. I am going to loosen this by turning it to the left about a quarter of a rotation. Let's test it again. Place it in the hand. Pull up.

It's still not leaving my hand, but when I jerk it, it does drop down a little. Let's do another quarter rotation to the left and try again. Now, that is probably too loose. See how freely it's letting it out? It's not putting up anything of a fight at all.  Let's turn it to the right just a smidge. Try again. Probably a little too loose. A little more to the right.

Right there, it wants to leave my hand, but it doesn't every time. Right there is perfect. That is a good bobbin tension right there. Now, you can put this in and know that it's correct. Now you are ready to adjust your needle tension.

Let's put it back in the machine. When you put your bobbin cases back in the machine, it might be tempting to hold this little horizontal lever when you put it in.  It's better, though, if you line everything up, and press in the center, so that you hear that click. That way you know it's properly seated, because you heard the click. Sometimes, you might put it in, and think it's in, but it's not in. Then when you begin to sew, your needle will come down and hit your bobbin case. That's would be a problem. Now it's back in.

Let's pull up the bobbin thread and get ready to sew on this little Kenmore again.
Well, thank you so much for watching. I hope that helped you to set your bobbin tension on your sewing machine. If it did, please give my video a Like. If you have anything to say, or have any more questions, please leave them in the comments on the video. If you are into sewing deep dives like this, please consider subscribing to our channel.

If this isn't working and you think you need a new bobbin case, check out our Singer metal bobbin case that works on a variety of machines.  Is your bobbin case rusty, rough, or misshapen? Is the screw hole stripped out, making the screw unable to hold tension? If so, it's time to replace the bobbin case.