Whether you’ve been sewing for decades and have seen more sewing machines than you can count, or you’ve only seen a few in passing at the craft store you can easily spec out that sewing machines come in a wide assortment of options ranging from simplistic designs to more intricate ones. Whether it’s a simple alteration or a more involved project, the sole purpose of a sewing machine is just that – to sew. But how does it work? Just like people, we all look different, but our compositions are ultimately the same and a sewing machine is quite like that. Without further adieu, we are going to do a little detective work to dissect the inner workings of the sewing machine and figure it out!

The Basics: Threading a Sewing Machine
- Thread the upper sewing machine needle by placing a spool of thread on the spool pin, pull the end of the thread to the right to place it in the thread guide starting from the back, letting it follow the U shaped guide to the take-up thread to hook it in place and come back down, place the thread through the needle.
- Wind a bobbin by moving the bobbin winder to the left then placing the thread on the spool pin grabbing the end of the thread to loop the thread around the circular section of the thread guide one complete time then send the thread back toward the bobbin winder.
- With a bobbin spool in hand, bring the end of the thread up through the bottom of it, placing it on the bobbin winder pin. Move the bobbin winder to the right and press the pedal to start winding. Hold the thread end in place until you have established a clean winding then wind until your bobbin is filled to the desired amount.
- Thread the bobbin by raising your needle and removing the bobbin cover plate, then place the bobbin spool in the compartment, making sure that it will unwind in the counterclockwise direction. Continue by placing it in the bobbin case slots to ensure that the bobbin thread won’t slip.
Let's Talk Engineering: How A Sewing Machine Sews
You have everything properly threaded and now you’re ready to get stitching, but you start to wonder how these stitches are actually made.
Let’s talk engineering:
- First things first, the take-up lever is right above the presser foot. It moves the needle up and down, releasing the tension on the thread and piercing through the fabric and the area beneath it so that the bobbin hook can grab the thread and make a loop that goes around the bobbin.
- Next, the needle pierces the fabric with the help of the feed dogs to move the fabric along the throat plate.
- Now, the take-up lever continues working by taking the thread down as the needle plunges into the fabric to release the tension on the thread
- This is so that the bobbin/shuttle hook can grab it and form a loop that goes around the bobbin thread.
- Once it makes a round trip, the take-up lever goes up as the needle comes up, tightening the bobbin thread under the fabric to complete a single stitch.
