Troubleshooting Thursdays: What to Do When Your Sewing Machine's Lower Thread Breaks

Before you pick up the phone to call the sewing machine repair business, there might be a few things to check beforehand that can solve this issue.  

1.  Check to make sure that your bobbin has been properly wound

You will want to start with a empty bobbin.  Don't wind one colour of thread over another to save time.  It isn't worth the hassle if your bobbin threads unevenly.  You want to have your bobbin filled evenly across and in level layers.  If one end of the bobbin is more dense that the other side this can cause thread break issues.  

2.  Check your thread

When it comes to sewing you want to make sure that your upper thread is identical to the lower thread to achieve smooth stitches.  Of course, there are exceptions to this rule, based on specific machines (embroidery) and sewing techniques.  

Elastic thread is used in the bobbin area only to achieve shirring.  For this technique wind the elastic thread by hand until the bobbin is 2/3 full.  You can wind the bobbin by machine but if you do remember to do so at a very slow speed as not to stretch out the elastic thread.  

3.  Check if your bobbin is bent

Just like a bend needle, a bent bobbin can cause thread breaks as it will interfere with the timing of the other parts of the machine.  If your bobbin is bent, just replace it.  This also goes for any bobbin that is worn, nicked or cracked.  

4.  Check for lint built-up in the bobbin case

I can't advocate enough for frequent cleanings. I learned this lesson the hard way, I'm a convert now.  The $ I could have saved / spent on fabric instead of handing it over to the sewing machine repair shop, don't get me started!  Ideally, I like to do this at the end of a project, just before I start the next. 

Don't use canned air to clean out the lint that has accumulated in your machine.  You don't want it to blow into an area that you won't be able to reach.  Take care and time using the lint brush that came with your machine.  You can even pick up a mini vacuum found in fabric store notion departments.  

5.  Check that the bobbin is inserted correctly

Oy, how many times have I failed to insert a bobbin correctly!  I usually catch this before I start sewing as the needle won't catch the lower thread if this is the case.  In some cases if a bobbin is inserted incorrectly and depending on your bobbin case, it can cause the thread to catch on a spring or latch on the bobbin case.  

6.  Check that it's the correct bobbin for your machine

L to R:  Plastic bobbin for Janome sewing machine, medal bobbin for vintage Brother sewing machine, generic plastic bobbin sold at fabric store, bobbin case for Singer treadle sewing machine, full and empty bobbins for Singer treadle sewing machines.  

Fabric stores often sell generic bobbins that they claim with work in a variety of models but sometimes that may not be the case. If at all possible, pick up your bobbins from the sewing machine dealer.  They will carry specific types designed for your machine.  Vintage bobbins are harder to come by.  These can often be sourced from online dealers or second hand shops.  

Happy Sewing!