Symptoms
- Machine won't move or makes a grinding sound
- Thread visibly wrapped around the bobbin area underneath
- Needle jams partway through a stitch
- Fabric won't feed and thread is knotted below it
Likely causes
- CommonThread wrapped around the bobbin hook or shuttleA tangle can wind tightly around the rotating hook and physically stop it from turning.
- CommonBobbin case inserted incorrectlyA bobbin case that isn't seated or clicked in properly can catch and jam the mechanism.
- CommonLint and thread debris built up over timeFuzz from thread and fabric accumulates in the bobbin area and can eventually cause jams.
- PossibleWrong bobbin type for the machineUsing a bobbin from a different machine model, even if it looks similar, can cause fit and jamming issues.
- Less commonBent bobbin case or hookA dropped bobbin case or hook impact can bend the part enough to catch thread repeatedly.
What to do
- Turn off and unplug the machine, then remove the needle plate to access the bobbin area per your manual.
- Take out the bobbin and bobbin case, and carefully cut away and remove all tangled thread with small scissors and tweezers, being gentle around metal parts.
- Brush out lint and thread fuzz from the whole bobbin area with a small brush.
- Inspect the bobbin case for any visible bend or damage; replace it if deformed.
- Confirm you're using the correct bobbin type and size specified for your exact machine model.
- Reinsert the bobbin case until it clicks or seats fully, following the threading diagram in the manual.
- Hand-turn the wheel a full rotation to confirm everything moves freely before plugging back in and testing.
Tools and parts
- Small scissors
- Tweezers
- Small brush
- Screwdriver (for needle plate)
Bobbin caseSearch: “sewing machine bobbin case for your model”
When to call a pro
If the jam recurs often or you find a bent hook or case, a sewing machine repair shop can replace the part and check timing.
Safety
Use caution
Unplug the machine before reaching near the needle and hook mechanism, since an accidental foot pedal press can cause injury.