Five Common Sewing Machine Mistakes + How to Fix Them
Sewing machine acting up? Thread knotting underneath? Stitches looking wonky? You're not alone – these are some of the most common sewing machine problems beginners (and even experienced sewists) run into.
The good news is that most sewing machine issues aren't actually faults with the machine. They're often simple setup mistakes that take seconds to fix once you know what to look for.
This guide covers the five most common sewing machine problems, why they happen, and exactly how to solve them so you can get back to sewing without frustration.
Why sewing machines seem to "throw tantrums"
Sewing machines are precise pieces of equipment. When everything is set up correctly – thread tension balanced, bobbin inserted properly, presser foot down – they work beautifully. But miss one small step, and they stop cooperating.
The problems below are the ones that come up again and again, whether you're brand new to sewing or you've just had a moment of distraction and skipped a step.
It’s always a good idea to sew a test swatch on a scrap of fabric before starting your project so you can check everything is order.
Problem 1: The needle unthreads itself when you start sewing
You've just carefully threaded the needle, positioned your fabric, pressed the pedal... and the thread immediately pulls out of the needle. Frustrating!
Why this happens:
Cause 1: Not enough thread tail pulled through the needle.
Cause 2: The needle isn't at its highest position when you start sewing.
How to fix it:
Solution 1: Leave a longer thread tail
After threading the needle, pull at least 10cm (4in) of thread through toward the back of the machine. This gives the thread enough length to stay anchored in the needle as the machine begins stitching.
Solution 2: Raise the needle to its highest position
Before you start sewing, make sure your needle is at the top of its stroke. You can check by making sure you can fully see the take-up lever (the little silver hook or arm at the top). If you can't see it, turn the handwheel toward you until it appears at its highest point – or press the needle up/down button if your machine has one.
This one took me a little while to discover when I first began sewing, but starting with the needle down or mid-position can cause the thread to slip out. When the needle is at its highest position, the thread loop is properly formed and ready to create the first stitch.
Problem 2: The fabric is jiggling around like crazy
You're trying to sew a straight line, but the fabric is sliding all over the place and your stitching looks like a drunk snake!
Why this happens:
You forgot to lower the presser foot.
How to fix it:
Lower your presser foot before you start sewing. The presser foot is the metal (or plastic) foot that sits on top of the fabric. It holds the fabric firmly against the feed dogs (the little teeth under the needle that move the fabric through the machine).
Without the presser foot down, the fabric has nothing holding it in place, so it moves around freely instead of feeding through evenly. With the presser foot down, the fabric is held firmly and feeds through smoothly, giving you neat, straight stitches.
Where's the presser foot lever? Usually at the back of the machine, behind the needle. Lift it up to raise the foot, press it down to lower the foot.
This is such a common mistake that even experienced sewists occasionally forget – especially when you're concentrating hard on positioning fabric perfectly!
Problem 3: The stitching looks really uneven (loopy on one side, tight on the other)
Your stitches look fine on the top of the fabric but loopy and messy underneath. Or vice versa – tight on top, loopy underneath.
Why this happens:
Cause 1: Bobbin is inserted incorrectly (this affects tension too).
Cause 2: Thread tension is unbalanced.
How to fix it:
First, check the bobbin:
Before adjusting anything else, remove your bobbin and check:
- Is it inserted the right way round? Check your machine manual for which way the thread should unwind.
- Is the thread pulled through the grooves in the bobbin case? There's usually a small slot or groove the thread needs to sit in. If the thread isn't in this groove, tension will be completely off.
Reinsert the bobbin correctly and test sew on a scrap of fabric. This fixes the problem 80% of the time.
Still uneven? Adjust the tension dial:
If the bobbin is definitely correct and stitches are still uneven, adjust your tension dial:
- Loopy stitches on top = tension too loose → Turn the dial to a higher number
- Loopy stitches underneath = tension too tight → Turn the dial to a lower number
Make small adjustments (half a number at a time) and test on scrap fabric between each change.
Most machines’ default tension is 4 or 5 (check your manual) – if you've changed it significantly, try returning to the default and starting from there.
Read more tips for balancing the thread tension on your sewing machine.
Problem 4: Your stitching is crazy tight on the top side
The stitches on top of your fabric are so tight they're puckering the fabric, but underneath looks normal.
Why this happens:
Cause 1: The spool thread is caught on the bobbin winder guide at the top of the machine.
Cause 2: The spool pin is sticking to the label at the end of the thread spool.
How to fix it:
Solution 1: Check the thread isn’t caught on the bobbin winder
The bobbin winder guide is the set of small silver tension discs near the top of your machine (usually near where the thread spool sits).
When you wind a bobbin, you thread the spool through this guide to create resistance as the thread winds. But when you thread the machine for normal sewing, the thread should not go through these discs, otherwise they’ll pull the spool thread far too tight and create puckered, over-tensioned stitches.
Solution 2: Remove any labels from the end of the thread spool
I know it sounds silly, but if the sticky label gets stuck on your spool pin, the thread won’t unravel smoothly. So take a second to check, and you can thank me later!
Problem 5: The threads are knotting up together (thread nests/bird's nests)
Your threads are tangling into knots either on the fabric, or worse, jamming underneath in a messy "bird's nest" that requires unpicking or even unscrewing the needle plate to remove.
Why this happens:
Cause 1: Thread tails not pulled to the back before starting
Cause 2: Starting to sew right at the very edge of the fabric
Cause 3: Trying to back tack (reverse stitch) off the edge of fabric
How to fix it:
Solution 1: Pull both threads to the back before you start
Before pressing the pedal, make sure both the spool thread and bobbin thread are pulled out toward the back of the machine (at least 10cm/4in). Hold them gently as you start the first few stitches.
If the threads aren't pulled back, they can get caught in the bobbin mechanism and tangle together underneath the fabric.
Solution 2: Start sewing a little way in from the edge
Don't start your first stitch right at the very edge of the fabric. Instead:
- Position your needle about 6mm (¼in) in from the edge
- Sew forward a few stitches
- Back tack (reverse stitch) to the edge
- Sew forward along your seam line
Why this works: If there's not enough fabric under the needle when you start, the spool thread gets pulled down into the bobbin area and tangles with the bobbin thread, creating a knotted mess (and sometimes pulling the fabric edge down into the machine with it — nightmare!).
Solution 3: Don’t back tack off the edge of the fabric
When you reach the end of a seam, back tack a few stitches before reaching the edge, then sew forward off the end of the fabric. If you sew off the edge and then try to back tack back onto the fabric, this almost always causes thread nests because there's no fabric under the needle to hold things in place.
Quick troubleshooting checklist
Before you panic that your machine is broken, run through this checklist:
✓ Is the presser foot down?
✓ Is the needle at its highest position?
✓ Are both thread tails pulled to the back?
✓ Is the bobbin inserted correctly (and in the right direction)?
✓ Is the bobbin thread pulled through the groove in the bobbin case?
✓ Is the spool thread caught on the tension discs (when it shouldn't be)?
✓ Are there any labels on the spool sticking it to the spool pin?
✓ Are you starting a few mm in from the fabric edge (not right on the edge)?
✓ Is the needle threaded correctly with enough tail?
Nine times out of ten, one of these issues is the culprit.
When it might actually be a machine issue
Occasionally, sewing machine problems aren't user error. Here's when the cause might be something else, or you might need professional help:
The needle keeps breaking → Could be a bent needle, wrong needle type for your fabric, or timing issue (the last one needs professional servicing)
The machine won't pick up the bobbin thread → Timing might be off (needs a technician)
Strange noises or grinding sounds → Might need cleaning, oiling, or servicing
Thread keeps breaking → Could be old/weak thread, wrong needle size, or a rough spot on the needle plate
Stitches skipping randomly → Often a needle issue (wrong type, bent, or blunt) or timing problem
Most machines benefit from a professional service every 12-18 months, especially if you sew regularly.
Want help getting to grips with your sewing machine?
If you're new to sewing and want to build confidence with your equipment, our Make Friends with a Sewing Machine workshop takes you through everything from threading and tension to troubleshooting common problems.
You'll learn:
- How to thread your machine correctly
- When to adjust tension (and when to leave it alone)
- Stitching techniques that prevent thread nests
- Basic sewing machine care to keep it running smoothly
