Five sewing mistakes beginners make (and how to fix them)
When Emily and Sam ran the Crafternoons in Yorkshire ten years ago, the same five problems came up in nearly every workshop. They're still the most common questions we get by email today. Here they are, with the fixes that actually work at the machine.
1. The thread keeps snapping
Almost always one of three things, in order of likelihood:
- The upper thread isn't fully seated in the tension discs. Rethread the upper thread with the presser foot lifted (this opens the tension discs so the thread can slip in). If you thread with the foot down, the thread sits on top of the discs instead of between them, and the machine pulls against it until it snaps.
- The needle is the wrong size for the thread. A size-70 needle with thick upholstery thread will snap. Match needle size to thread weight.
- The thread is old. Polyester thread degrades. If your thread is from a charity-shop tin from 1984, it'll break under any tension.
2. The stitches are skipping
The pattern shows up as gaps in the seam, sometimes every fourth or fifth stitch is missed. This is almost always the needle, not the machine.
- Use a ballpoint needle on jersey and stretchy fabric. A regular sharp needle splits the knit fibres rather than going between them, and the hook can't catch the thread on every stitch. Schmetz makes a ballpoint or "stretch" needle that costs about £4 and fixes 90% of skipped-stitch problems on knit fabric.
- Replace the needle. Even on woven fabric, a dull or slightly bent needle will skip. Needles are cheap. Change yours every 8–10 hours of sewing, or whenever the machine starts misbehaving for no clear reason.
- Check the needle is inserted the right way around. The flat side of the shank goes towards the back of the machine, almost always. If you've put it in backwards, you'll get skipped stitches immediately.
3. The seam is puckered
The seam looks gathered or wrinkled along its length instead of lying flat. Three usual causes:
- Upper thread tension is too tight. Drop the tension dial down by one or two numbers and sew a test seam. The two threads should be balanced — neither one pulling the other to its side.
- Stitch length is too short. On fine cotton or silk, very short stitches gather the fabric. Increase the stitch length to about 2.5–3mm.
- You're pulling the fabric. Let the feed dogs do the work. Your hands guide, they don't pull. Pulling the fabric through faster than the machine wants to feed it creates puckers.
4. The bobbin tension is wrong
You can see it from the underside of the fabric. The bobbin thread is forming loops, or the upper thread is pulled all the way through to the back. Two cases:
- Loops on the underside. Almost always means the upper thread isn't threaded correctly. Re-thread it from scratch with the presser foot lifted. This fixes the problem 95% of the time. (See mistake #1.)
- Bobbin thread visible on the top. The upper tension is too high. Lower it by one dial position at a time and re-test.
Almost no beginner needs to adjust the bobbin tension itself. If the thread path is correct and the upper tension is reasonable, the bobbin tension is fine where the factory set it.
5. The needle keeps breaking
Three causes, all easy to fix:
- Pulling the fabric while sewing. The needle is brittle. It's designed to move straight up and down. Sideways force snaps it. Guide the fabric, don't drag it.
- Sewing over pins. Eventually the needle hits a pin and breaks. Pull pins out as they reach the foot, or use wonder clips instead.
- Needle too small for the fabric. Trying to sew denim with a size-70 needle will break it. Size up.
The thread that ties them all together
Almost every mistake on this list comes down to one of three things: re-thread the upper thread, change the needle, or slow down. If something isn't working and you can't tell why, do those three things in that order. Fix rate, in our workshop experience: about 85%.