Possibly the most common reason a machine ends up on my bench is for tension.  Usually bird’s nests.  The thing is easily 80% of the time, there’s nothing really wrong with the machine that a repair person needs to look at it.  Sometimes it’s basic maintenance, sometimes it’s because someone told you at some point “DON’T YOU TOUCH THAT! EVER!”

I’m sure that the people who’ve said that meant well, but today I’m going to show you how to manage that dial properly and what to do when it’s not proper.

I’m sure there are some of you out there who are thinking, “no no, she’s talking about that which shall not be touched”…. but it’s true.  That tension knob is meant to be adjusted by you!

Here are 3 clues to the truth of this statement:

1. They talk about tension adjustment in the owner’s manual.  Many manuals even touch on both the upper and bobbin tensions.
2. It’s within easy reach of you when you operate the machine.
3. If it wasn’t meant to be user adjusted, it wouldn’t have numbers on it.  (Yes, I know that some of the older machines don’t have numbers, but for the sake of simplicity, for the moment, let’s pretend they do)  Your OSMG (Old Sewing Machine Guy, Gal or Glutton-for-punishment) has no need of numbers.  We use feeler gauges and fancy measuring tools like bags full of Kamut berries.

I find that tension problems can be broken up into 4 major groups.

1. Something on the machine is assembled wrong, broken, or missing.  This is really common when a machine is used but new to you.  Often people have taken things apart, reassembled wrong, gotten frustrated and unloaded the source of their frustration on you.
2. The sewist operating the machine has been taught to never adjust the tension on a machine – often this person will tell me too “my machine doesn’t like x thread (or x fabric), or it doesn’t like piecing (quilting, FMQ, jeans, light fabrics, heavy fabrics, etc)
3. The sewist has never heard the above rule, but doesn’t understand tension, and just turns and turns until it works out right.  Sometimes this person will tell me the same things as #2, or say that they really have to fight to change fabric types (thread types, project types, etc)
4. The machine is in need of some basic maintenance.

Note:  You may have noticed that I don’t call us sewers.  That’s because we’re not a bunch of pipes where shi…. crap and toilet paper collects.  Sewists reads better, even if my spell check doesn’t like it.

Note 2:  I’m not picking on anyone.  We’re all products of our learning, and some of us were taught to be terribly cautious, and some of us are tinkerers.  I fall into that second category.  I bet you’d never have guessed that though. 😉

Here’s a fundamental truth of sewing machine tension:

If the thread is fully seated in between the tension disks, and it’s threaded right using an appropriate thread and needle for the application, and the tension dial is somewhere between 3 and 5 (assuming a scale of 0-9), it should work, unless someone has messed with either the top or bottom thread tensions.

This is most applicable for “regular sewing”.  Let’s leave free motion and decorative stitches for the moment. I’ll address it later, I promise.

Tension doesn’t have to be difficult.  It doesn’t have to cause you stress.

If you’re experiencing some trouble with a machine, I’d like to walk you through a few little tests to see if we can pin point where the problem is.  In the next couple of articles, we’ll talk about the things that can go wrong, which symptoms point to which problem, and adjusting the things that need to be adjusted when something’s actually gone wrong.

First, make sure there are no obvious pieces of your upper tension assembly missing or broken.  No, I’m not suggesting that you disassemble it and count the parts. 🙂  If this is a new machine to you, try searching the Internet for a clear photo of the upper tension on your machine.  Going to Google, or Bing for instance and typing: Singer 401A Tension then clicking on Images gets me lots of great photos to compare with.

 

• For exposed tensioners, pay particular attention to the tension spring.  Often it’s mangled or broken off or in the wrong spot.
• Another clue to a mis-assembled upper tensioner on an exposed tensioner is the dial should turn to 0 and stop.  If the nut that holds the thing together just turns til it falls off, this is wrong.  Don’t worry, it’s not ruined for good, it just needs to be reassembled correctly. The knob should also give you the full range, all the way from 0 – 9 and you should be able to feel the tension change between the disks.  Just going from 0 – 7 (for instance) indicates the tensioner is mis-assembled.

Next, let’s check how the upper tension is working.  To do this, use a 90/14 needle, it doesn’t matter what type of needle (denim, knit, etc) and thread using a 50wt thread. (Gutermann sew-all thread is unlabelled as to weight, but it’s typically about a 50wt thread, so it’s fine here.):

1.  With the presser foot up, turn the tension dial to 0, and with the machine threaded properly up to, but not through the needle, pull on the thread. Note how it feels when you pull the thread.

Now put the presser foot down. It should feel really close to the same, maybe a smidge tighter, turning the dial to 1 should put noticeable drag on the thread.

2.  With the presser foot still down, thread the needle.  Now start slowly turning the dial to raise the tension while pulling the end of the thread.  Pull the thread in the direction the thread would normally feed (ie. if you thread right to left – pull left, if you thread front to back, pull backwards)  By the time you reach 3 – 5, there should be enough tension on the thread that the thread should “deflect” the needle some (maybe about a 1/16″ – or about 1.5mm) before the thread starts to pull out further.

3.  Take note of the number where the deflection is about 1/16″.  This is where your tension will normally be “right” for the majority of your sewing.

Here’s a video of what I’m describing here:

Fast tension test – this works on most machines, not just vintage

If the tension doesn’t behave this way, then it likely has been / needs to be adjusted.  If that is all about right, and the tension problem still hasn’t gone away, I would say it’s time to look at the bottom tension.

If by the time you reach 3 -5, it hasn’t changed at all or only a tiny bit, chances are one of 2 things has happened:

• There’s fluff, old oil, debris, or small kittens in the tension disks. Try running some dental floss through to clean out the garbage. I’ve also been known to turn the tension dial to 0 (or make sure the presser foot is up) and gently spread the disks and blow out any debris I see.  This is also good for a visual inspection after running the floss through.  This obviously works better for the exposed, external tensioners than the ones that are integrated.
• The thread isn’t right into the tension disks – try this:

1. Thread the machine up to the tension disks with the presser foot up.
2. Thread through the disks, then drop the presser foot
3. Grab the threads going into and out of the tension disks, and give them a gentle tug upwards.  This is right for most vintage machines.  If your tensioner isn’t exposed, try to push the thread in as far as possible. For instance, I will usually hold the thread before the tensioner, then pull the thread after it leaves the tensioner.  This usually has same effect as doing what I suggested above for exposed tensioners.  This will make sure that the thread is fully seated. I used to have a lot of weird tension issues with some machines before I started doing this.
4. Raise the presser foot, and continue threading the machine.
5. Do the tension tests above again and see if the result is different.

If the tension is really tight right from the get go, or the needle starts to deflect significantly between 0 and 3, one of 2 things has likely happened:

1. Somewhere in the thread path, the thread has become caught on something that’s not letting it move freely.  Check and double check your routing and make sure the thread isn’t hung up on anything.
2. Your tensioner has more than likely been adjusted incorrectly.  We’ll address this in a later article.  In the meantime, many vintage machine owners can benefit from this link on the “Tools for self-reliance” website – note, it’s a PDF file.
   This PDF addresses the Singer machines, but the clones (Many of the Made in Japan machines from the 50 – 70s) will work too, it just takes a little imagination to see how some of the parts were redesigned.  2016-10-21 The manuals from TFSR are offline at this time.  They can still be found at: https://web.archive.org/web/20160901183756/http:/www.tfsr.org:80/publications/technical_information/sewing_machine_manual/
   
   

This is the simple test I do to machines first when someone complains of tension.  After that, I get more accurate.

Did this help?  Raise more questions than it answered?  Let me know below, we’ll get you sorted out.

Checking Bottom Tensions

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