Needle not picking up the bobbin thread
Usually a turned or dull needle, a bobbin put in the wrong way, or a threading mistake.
Why the bobbin thread stays down
To bring the bobbin thread up, you hold the top thread and turn the handwheel toward you one full turn: the needle goes down, the hook catches its loop, carries it around the bobbin, and the loop comes back up holding the bobbin thread. If no loop comes up, the hook never caught the top thread. Brother's answer for this lists three causes: a needle that is turned, bent or dull; a bobbin set in incorrectly; and incorrect upper threading.
Work through these in order
- Check you are turning the handwheel toward you a full turn, and holding the top thread lightly so it can be pulled.
- Fit a new needle, pushed fully up and facing the right way. A turned needle puts its loop out of the hook's path.
- Take the bobbin out and put it back the way the manual shows. On Brother and Singer drop-in machines that means turning counterclockwise seen from above, with the thread through the slit and under the spring.
- Rethread the top with the presser foot up.
- Check nothing traps the bobbin thread. Singer notes the 4423's hinged cover or extension table can pinch it.
Brother's quick-set drop-in machines (XM2701, LX3817, CS7000X) can start sewing without drawing the bobbin thread up at all; the first stitches pull it up.
On vintage Singers
A Featherweight, 15-91 or 401A that still will not pick up the bobbin thread after a new needle, correct threading and a clean hook may have its hook or needle bar out of position. Check the needle bar timing marks as described on the Featherweight, 15-91 and 401A pages. On the 15-91, also confirm the bobbin case is the 11 o'clock case, Singer 125291; a generic Class 15 case will not seat properly.
On your machine
- Brother XM2701, LX3817, CS7000X
- Singer Heavy Duty 4423, Janome HD3000, Juki TL-2010Q
- Featherweight 221, Singer 15-91, Singer 401A