The sewing machine is an invention of advanced engineering developed over several centuries and incorporating mechanisms of horizontal and vertical rotation to produce an accurate and regular stitch. From lockstitch, to buttonhole, decorative, embroidery and stretch stitches, the humble sewing machine is quite amazing. We pick up our sewing machines, thread them up and expect them to work… and mostly they do! But when they don’t it’s easy to assume that there is a fault when really all they need is a little TLC.
The mechanics of the sewing machine
It’s worth taking a moment to think about what’s going on under the fabric because it’s deceptively simple. There is an electric motor driving an upper shaft, which then drives the lower shaft and other mechanisms involved in forming a stitch. The ranges of motions are horizontal for the shafts but this is then translated into vertical motion for the stitch forming mechanism. In addition, gears will be driving the hook that links the top thread to the lower thread, plus shafts and cams (or sometimes belts or gears) making the feeder (moves the fabric along) synchronise with the stitch forming mechanism and hook. There may be additional parts driving the needle from side to side. There could also be a thread cutter mechanism. There is a lot of complex machinery involved in creating a simple stitch!
This animation from Threads Magazine gives a really clear idea of what’s going on when a stitch is formed:
An average domestic sewing machine creates stitches between 800 and 1200 times a minute (and industrial machines can be 5000 stitches per minute!) so there is quite a margin for things to go wrong. We all love our sewing machines, so let’s see how we can help them with a bit of TLC to keep them happy!
Back to basics
First of all, let’s quickly go over a couple of basics that you all probably know, but are easy to forget when your machine isn’t behaving as you would like.
- You need a good needle – sharp, not bent, inserted correctly and of the correct type for the fabric and thread. A lot of problems can be caused by old or incorrect needles, so make sure you replace them regularly.
- You also need a decent quality thread. Cheap or poor quality threads will shred more readily, causing breakages and lint to build up inside your machine.
- The upper and lower threads need to be threaded correctly. Have a look at the threading guide in your machine’s user guide, you might be surprised to find a few useful tips in there. Make sure you floss your top thread through your tension disks and that your bobbin is positioned with the thread in the right direction.
Owing to the nature of fabric and thread, sewing machines get full of lint and fluff. Over time this compacts down and can almost form another layer over the metal parts. We have seen feed dogs so full of lint they cannot lift the feed teeth above the stitch plate and so much fluff inside the machine that a hamster could be living in there!
Different fabrics create different amounts of lint. As you might expect, anything with a nap will create more lint and fabrics like velvet and towelling can create a great deal very quickly. You can see just how much fluff can build up with regular use over time in the image above. The grey part you can see to the right with the coloured wires coming out of it is the motor, which can heat up as the machine is being used. With a big enough build-up of lint, the heat from the motor can actually ignite the lint.
Both upper and lower threads are controlled by tension devices. Thread or lint can stick between the two tension disks or under the bobbin case tension spring. The tension device on more modern machines can be concealed into the front of the machine, but just follow the threading path to find them – they are normally near the adjusting dial.
To clean between the tension disks, raise the presser foot to open the disks and drag a non-linty piece of fabric (e.g. calico or quilter’s cotton) or a blunt needle end between the disks.
To clean under the bobbin case spring, gently run a needle between the spring and the body of the bobbin case.
If you want to learn more about tension and how to adjust it, take a look at my post from September 2021, Tension caused by tension.
Please do not remove any covers around the tension device that are not mentioned in the instruction manual as being removable. Leave that to trained service technicians!
Wear and tear
All the surfaces that the threads pass over need to be smooth and undamaged by needles or wear and tear. Any of the stitch forming parts (thread paths, presser foot, needle plate, and shuttle hook or bobbin case) can become worn or damaged by usage, but they can be cleaned up to a point with a bit of fine emery.
So, a bit of cleaning (and on some machines a drop of oil – but please check your manual before oiling your machine as some, especially computerised machines, do not require oiling), can go a long way! Have a look at our YouTube Channel for some help with this, your instruction manual will have some information too.
It’s worth cleaning your machine out regularly to prevent build-up and compaction of lint. You can use the pipe attachment on your vacuum cleaner, after removing any loose items of the machine that might disappear up it first of course! It is advisable to wear a dust mask as well as glasses or safety glasses to protect your eyes.
Safety warning: Please turn off the power to the machine and remove the needle before doing anything. A dust mask and safety glasses are also strongly recommended.
Getting a service
Even with a regular cleanout at home, every 1-2 years (dependent on usage) it’s a good idea to have your machine professionally serviced and set back to the manufacturer’s specifications. This will ensure that all the stitch forming parts are polished to allow the thread to flow over them freely, that all the mechanisms and timings are correctly set up so they work together correctly, and that the tensions and reverse stitches/buttonholes are correctly balanced. It will also include a check of the electrics for safety and condition, as well as a PAT test. You should get a service report with the machine, giving a list of checks performed, and pointing out any advisories.
Special service offer
If your sewing machine or overlocker is in need of a service, why not take advantage of our current special offer and get at least 10% off the regular price? If you have more than one machine serviced at the same time then the discount is even bigger, so why not get together with friends and save?! All you need to do is quote voucher code Sew22 when you book your service. If you can’t get your machine to us then don’t worry, we can help with collection and delivery too. Please see our service page for more information.
Hopefully this will help you to keep your machine in tip top condition, ready to serve you on projects old and new! Happy stitching!