Symptoms
- Loops of thread tangled underneath the fabric
- Fabric jams or won't feed after a few stitches
- Loud clunking or the needle refuses to move
- Bunching happens right from the first stitch
Likely causes
- CommonMachine not threaded correctly on topIf the upper thread misses a tension disc or guide, it won't hold proper tension against the bobbin thread.
- CommonBobbin inserted incorrectly or wound unevenlyA bobbin put in backwards or wound with uneven tension causes the underside thread to loop and tangle.
- CommonPresser foot not loweredWith the foot up, the tension discs stay open and the top thread has no resistance, causing immediate bunching.
- PossibleWrong needle size or a dull/bent needleA mismatched or damaged needle can snag thread and disrupt the stitch formation.
- PossibleLint or thread buildup in the bobbin caseDebris in the bobbin area interferes with smooth thread release.
What to do
- Raise the presser foot, remove the fabric, and rethread the top of the machine from scratch, following the threading path exactly, with the presser foot up.
- Lower the presser foot before you start sewing; this is required for correct tension.
- Remove the bobbin and reinsert it, checking that the thread pulls off in the direction shown in the manual and that it isn't wound unevenly.
- Pull both top and bobbin threads back and to the side under the presser foot before starting a new seam.
- Clean out lint from the bobbin case and feed dogs with a small brush.
- Check the needle for burrs or bending, and replace it if it's been in use for a while.
- Test on a scrap fabric piece with the correct thread weight for that fabric before continuing your project.
Tools and parts
- Small lint brush
- Screwdriver (for needle plate, if needed)
Sewing machine needleSearch: “universal sewing machine needle”
BobbinSearch: “sewing machine bobbin for your model”
When to call a pro
If rethreading and a clean bobbin case don't fix it, a sewing machine repair shop can check timing and tension components that aren't user-adjustable.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.