The bobbin goes in the bobbin case, which sits under the needle plate

The bobbin is the small spool that holds the lower thread in your Singer machine. To insert it, you first wind thread onto an empty bobbin using your machine's bobbin winder, then place the wound bobbin into the bobbin case — a metal or plastic housing that sits directly under the needle plate (the flat metal plate the presser foot sits on). The bobbin case is where the magic happens: the upper thread and lower thread lock together to form a stitch.

Most Singer machines use one of two bobbin systems: a drop-in bobbin that sits openly in a case under the needle plate, or a removable bobbin case that you take out to load. Your machine's manual will tell you which type you have, but you can also look under the needle plate — if you see a small metal or plastic housing you can unscrew or pop out, you have a removable case. If the bobbin sits directly in a round opening with no removable case, you have a drop-in system.

Key Takeaways

  • Wind the bobbin first using your machine's bobbin winder, which is usually located on top of the machine near the thread guides.
  • For a drop-in bobbin, raise the presser foot, remove the needle plate, and drop the bobbin into the case with the thread running counterclockwise.
  • For a removable bobbin case, unscrew or pop out the case, insert the bobbin with thread running counterclockwise, and thread the bobbin thread through the tension spring before reinserting.
  • The bobbin thread must pass through the tension spring in a removable case, or it will not catch the upper thread and your stitches will fail.
  • If your machine skips stitches or the lower thread breaks, the bobbin is often wound too loosely or inserted incorrectly — rewind and try again.

Winding the bobbin before you insert it

You cannot insert a bobbin into your Singer machine unless it has thread wound on it. To wind a bobbin, place an empty bobbin on the bobbin winder, which is a small spindle on top of your machine (usually on the right side, near where you thread the upper thread). Push the bobbin winder to the right or engage it according to your manual — this disengages the needle so the machine will not sew while you wind.

Thread the bobbin winder by running thread from your upper thread spool through the bobbin winder tension disc (a small metal or plastic piece with a slot), then wrap the thread around the bobbin a few times by hand to anchor it. Press the foot pedal or start button, and the machine will wind thread onto the bobbin automatically. Most machines have a sensor that stops the winding when the bobbin is full — you will hear a click or the winding will straightforward stop. If your machine does not stop automatically, watch the bobbin and stop when it is full but not overstuffed.

Remove the wound bobbin and disengage the bobbin winder by pushing it back to the left or following your manual's instructions. The bobbin is now ready to insert.

Inserting a drop-in bobbin

If your Singer has a drop-in bobbin system, the bobbin sits openly in a round case under the needle plate with no removable housing. To insert it, first raise the presser foot (this is important — raising the presser foot opens the tension discs so the upper thread does not catch). Remove the needle plate by unscrewing the two small screws that hold it in place, or by sliding it out if your model uses a snap-fit design.

Look into the opening under the needle plate. You will see a round metal or plastic bobbin case with a small slot or opening. Hold the wound bobbin so the thread end points toward you, and drop it into the case. The thread should run counterclockwise around the bobbin when you look at it from above. Pull the thread end up and to the left, and it will rest in a small notch or slot in the case — this is correct. Replace the needle plate and tighten the screws firmly but do not over-tighten, as you can crack the plate.

Raise the presser foot again, hold the upper thread with one hand, and turn the hand wheel (the large wheel on the right side of the machine) toward you one full rotation. This will bring the needle down and back up, and the upper thread will catch the bobbin thread and pull up a loop. Pull both thread ends toward the back of the machine and trim them. You are now ready to sew.

Inserting a removable bobbin case

If your Singer has a removable bobbin case, you will see a small metal or plastic housing under the needle plate that you can unscrew or pop out. Raise the presser foot and remove the bobbin case by unscrewing the single screw that holds it (usually on the left side of the case), or by pressing a release button if your model uses a snap-fit. Set the screw somewhere safe — it is straightforward to lose.

Hold the wound bobbin with the thread end pointing toward you. Insert the bobbin into the case so the thread runs counterclockwise. Now comes the critical step: pull the bobbin thread through the tension spring, a small metal or plastic clip inside the case. The thread must pass under the tension spring and sit in the slot or notch provided. If the thread does not go through the tension spring, your stitches will skip or the lower thread will break. Look at your manual or the inside of the case — many machines have a diagram showing exactly where the thread goes.

Once the thread is seated in the tension spring, hold the bobbin case by its handle and reinsert it into the machine. Align the case with the slot under the needle plate and push it in until it clicks or seats fully. Replace and tighten the screw. Raise the presser foot, hold the upper thread, and turn the hand wheel one full rotation to catch the bobbin thread. Pull both thread ends toward the back and trim them.

Troubleshooting bobbin problems

If your machine skips stitches, breaks thread, or produces loose loops on the back of your fabric, the bobbin is often the culprit. The most common cause is a bobbin wound too loosely — the thread does not have enough tension to lock with the upper thread. Rewind the bobbin, making sure the thread is taut as it winds. If the bobbin winder tension disc is too loose, thread may wind unevenly; check that the thread passes through the tension disc slot and that the disc is not damaged.

If the machine still skips stitches after rewinding, remove the bobbin case and check that the bobbin thread is seated correctly in the tension spring (for removable cases) or in the notch (for drop-in cases). A thread that sits outside the tension spring will not catch the upper thread. Also check that the bobbin itself is not cracked or bent — a damaged bobbin can cause the thread to slip. If you have tried rewinding and reinserting and the problem persists, the tension spring may be bent or the bobbin case may need cleaning; a small amount of lint can prevent the thread from seating properly.

When to call a professional

If you have wound the bobbin correctly, inserted it according to your manual, and the machine still skips stitches or breaks thread, the problem may be inside the machine. A bent bobbin case, a damaged tension spring, or a misaligned needle can all cause bobbin-related problems that you cannot fix at home. A Singer service center or a local sewing machine repair shop can inspect the bobbin case and tension mechanism and replace parts if needed.

Do not force the bobbin case in or out — if it does not seat smoothly, stop and have it checked by a professional. Forcing a case that does not fit can crack the housing or bend the tension spring, turning a straightforward problem into an expensive repair. A technician can also clean out lint and debris that may be preventing the bobbin thread from seating correctly in the tension mechanism.

Frequently Asked Questions

Which way should the bobbin thread run?

The bobbin thread should run counterclockwise when you look at the bobbin from above. This is the standard for nearly all Singer machines. If the thread runs the wrong way, the upper and lower threads will not lock, and your stitches will be loose or skip entirely.

What happens if I forget to thread the bobbin through the tension spring?

The upper thread and bobbin thread will not lock together, and you will see loose loops on the back of your fabric or the machine will skip stitches. The thread may also break because it has no tension. Remove the bobbin case, rethread the bobbin thread through the tension spring, and try again.

Can I use a bobbin from a different brand in my Singer machine?

Most universal bobbins work in Singer machines, but check your manual first — some older or specialty Singer models use proprietary bobbins. Using the wrong bobbin size or type can cause the thread to slip or the bobbin case to not close properly. When in doubt, buy bobbins labeled for your specific Singer model.

How tight should the bobbin be wound?

The bobbin should be wound firmly and evenly, with no loose spots or gaps between thread layers. It should feel solid when you hold it, but you should not see the bobbin winder straining or hear the motor laboring. If the bobbin winder has an automatic stop, let it stop on its own — this means the bobbin is full enough.

Do I need to rewind the bobbin every time I change thread color?

Yes, if you want the lower thread to match or coordinate with the upper thread. You can leave a partially wound bobbin in the machine and use it later, but most sewers wind a fresh bobbin when they change upper thread colors so the stitches look consistent on both sides of the fabric.