The bobbin goes in the bobbin case, which sits under the needle plate
The bobbin is the small spool that holds thread underneath your fabric. To insert it, you first need to open the bobbin case — a metal or plastic compartment located directly under where your needle goes. On most Singer machines, you lift the presser foot (the part that holds fabric down), then remove the needle plate by unscrewing it or sliding it out, depending on your model. The bobbin case sits underneath.
Once you can see the bobbin case, you will notice a small latch or lever on the side. Pull or slide this to open the case. The bobbin itself — a plastic or metal spool wound with thread — slides into the case in a specific direction. The thread tail must catch in a small tension spring inside the case so the bobbin tension stays even while you sew.
Key Takeaways
- The bobbin case is located under the needle plate, accessed by lifting the presser foot and removing the plate.
- The bobbin thread tail must catch in the tension spring inside the bobbin case, or stitches will be loose and uneven.
- Most Singer machines wind bobbins on the machine itself using the bobbin winder on top, so you fill and wind before inserting.
- If your bobbin is empty or the thread breaks, you will see loose loops on the underside of your fabric.
Step-by-step insertion for a standard Singer machine
Start by raising the presser foot all the way up. This opens the tension discs on your machine and makes it easier to work. Next, locate the needle plate — the flat metal or plastic piece directly under the needle. Most Singer machines have a small screw on the right side of the plate. Turn it counterclockwise to remove the plate, or slide the plate toward you if your model uses a slide-out design. Set the plate aside where you won't lose the screw.
You will now see the bobbin case, which looks like a small metal or plastic shell with a latch. Pull the latch toward you or slide it to the side — the exact motion depends on your Singer model, but it should move freely without force. The bobbin case will either swing open or lift out completely. If it lifts out, set it on a clean surface.
Take your wound bobbin and hold it so the thread tail points toward the left side of the case. Slide the bobbin into the case with the spool sitting flat. The thread tail should naturally fall into the small notch or spring on the left side of the case — this is the tension spring. If the thread does not catch, gently guide it into the notch with your finger. The thread should sit snugly in the spring.
Close the bobbin case by pushing the latch back into place or reinserting the case into the machine. You will hear or feel a small click when it locks. Replace the needle plate and tighten the screw. Pull the bobbin thread up through the needle plate hole by turning the hand wheel toward you one full rotation while holding the top thread. This brings the bobbin thread to the surface, where you can thread it under the presser foot with your top thread.
Winding the bobbin before you insert it
Most Singer machines have a bobbin winder mounted on top of the machine, usually on the right side near the thread guides. Before you can insert a bobbin, it needs to be wound with thread. To wind, place an empty bobbin on the bobbin winder spindle and push it to the right until it clicks into place. This disengages the needle so the machine will not sew while you wind.
Thread the bobbin winder by running thread from your spool through the bobbin winder tension guide — a small metal or plastic piece with a slot. Then wrap the thread around the bobbin two or three times by hand to anchor it. Press the foot pedal or press the start button, depending on whether you have a mechanical or computerized Singer model. The bobbin will spin and fill with thread automatically.
The machine will stop on its own when the bobbin is full, or you can stop it by releasing the pedal. Remove the bobbin by pushing the winder spindle to the left. Trim the thread tail with scissors. Now the bobbin is ready to insert into the bobbin case using the steps above.
What happens if the bobbin is inserted wrong
If the bobbin thread does not catch in the tension spring, you will see loose loops on the underside of your fabric instead of tight, even stitches. The top thread will look fine, but the bottom will be a mess of loops. This is the most common sign that the bobbin was not inserted correctly or the thread did not seat in the tension spring.
If the bobbin is inserted backward or upside down, the thread may not unwind smoothly, and you could break the thread or jam the bobbin case. Always check that the thread tail is pointing toward the tension spring and that the bobbin sits flat and level in the case.
If you notice loose stitches after inserting the bobbin, remove the needle plate again, open the bobbin case, and reinseat the thread in the tension spring. Make sure the thread is sitting in the notch, not just resting against the side of the case. Close the case, replace the plate, and test on scrap fabric before sewing your project.
Different bobbin types on Singer machines
Singer makes several bobbin styles depending on the machine model. The most common is the plastic class 15 bobbin, which is small and round and fits into a removable metal or plastic bobbin case. Some newer Singer machines use a drop-in bobbin system, where the bobbin case is built into the machine and you straightforward drop the bobbin in from the top without removing anything. Check your machine's manual to see which type you have.
Class 15 bobbins are universal and work on most Singer machines made in the last 30 years. If you lose or break a bobbin, you can buy replacements at any fabric store or online. Drop-in bobbins are specific to certain Singer models, so order the correct type for your machine if you need extras. Using the wrong bobbin type can cause tension problems or damage the bobbin case.
Troubleshooting bobbin problems
If your bobbin keeps jamming or the thread breaks while winding, the bobbin winder tension guide may be dirty or the bobbin itself may be damaged. Clean the winder with a dry cloth and inspect the bobbin for cracks or rough edges. If the bobbin is cracked, discard it and use a new one.
If the bobbin thread breaks while you are sewing, stop when ready and remove the bobbin case. Check that the thread is still seated in the tension spring and that no lint or thread bits are caught in the case. Clean the case with a small brush or compressed air if you have it. Rewind a fresh bobbin and insert it following the steps above.
If the machine will not sew at all after you insert the bobbin, make sure the presser foot is down — the machine will not sew with the presser foot up, even if the bobbin is inserted correctly. Also check that the needle is inserted correctly and that the top thread is threaded through all the guides and the needle eye.
Frequently Asked Questions
Can I use a bobbin from a different brand in my Singer machine?
Class 15 bobbins are standard across most brands, so a bobbin from Janome or Brother will work in a Singer machine that uses class 15 bobbins. However, drop-in bobbin systems are brand-specific. Check your manual or the bobbin case itself — it usually says what type to use. Using the wrong type can cause tension problems.
Which direction should the bobbin thread tail point?
The thread tail should point toward the left side of the bobbin case, where the tension spring is located. The thread must catch in this spring for proper tension. If the tail points the wrong way, the thread will not seat correctly and your stitches will be loose.
How do I know if my bobbin is wound correctly?
A correctly wound bobbin should be full but not overstuffed — the thread should cover the bobbin evenly from top to bottom without bulging. If the bobbin is too full, the thread may not unwind smoothly. If it is too empty, you will run out of thread quickly. The machine's automatic stop should fill it to the right level.
What if the bobbin case won't close after I insert the bobbin?
The bobbin case will not close if the bobbin is inserted upside down or if the thread is caught outside the case. Remove the bobbin, check that it is sitting flat and level, and make sure the thread tail is inside the case and seated in the tension spring. Reinsert and try closing again.
Do I need to rewind the bobbin every time I sew?
No. You only need to rewind when the bobbin runs out of thread. Most bobbins hold enough thread for several projects depending on the size of what you are sewing. When you see the bobbin is nearly empty or the thread runs out mid-project, wind a fresh bobbin and swap it in.