Thread the bobbin before you insert it
A bobbin is the small spool that holds the lower thread in your sewing machine. Before you place it in the machine, you need to wind thread onto it and thread that thread through the bobbin case. Most machines come with empty bobbins and a bobbin winder — a small device on the machine itself that spins the bobbin to wrap thread around it evenly.
To wind a bobbin, place an empty bobbin on the winder spindle (a metal post, usually on the top or side of your machine). Pull thread from your upper thread spool and wrap it around the bobbin two or three times by hand to anchor it. Press the foot pedal or press the start button on your machine — the bobbin will spin and wind thread onto itself. Stop when the bobbin is full but not overstuffed; thread should cover the bobbin evenly without bulging. Remove the full bobbin from the winder.
Next, thread the bobbin through the bobbin case. The bobbin case is a small metal or plastic housing that sits inside your machine. Look for a slot or guide on the case — this is where the thread goes. Pull thread from the bobbin and slide it into that slot, then under a small tension spring or clip inside the case. The exact path varies by machine, so check your manual for the threading diagram specific to your model.
Key Takeaways
- Wind thread onto an empty bobbin using your machine's bobbin winder before you insert it into the machine.
- Thread the wound bobbin through the bobbin case by following the slot and tension guides shown in your machine's manual.
- Insert the bobbin case into the machine with the thread tail pulled out and ready to catch with your upper thread.
- Pull both upper and lower threads toward the back of the machine before you start sewing to prevent tangling.
Locate and open the bobbin case compartment
The bobbin case sits in a compartment on the front or side of your machine, depending on your model. Most machines have a small hinged door or a removable plate that covers this compartment. Look for a latch, button, or lever near the needle area — this opens the compartment door.
Some machines have a drop-in bobbin system, where the bobbin sits in a visible case that you can access without removing anything. Others have a removable bobbin case that you pull straight out. If your machine has a removable case, gently pull it toward you until it comes free. Set it on a clean surface where you can see the threading path clearly.
Insert the threaded bobbin into the case
Once the bobbin case is open or removed, hold the threaded bobbin with the thread tail pointing toward you. Slide the bobbin into the case so it sits flat and centered. The bobbin should spin freely without wobbling. If your machine has a removable case, you will see a small hook or post inside — this is where the bobbin spindle rests. Line up the hole in the bobbin with this post and lower the bobbin onto it.
Pull the thread tail out through the slot in the case. This tail needs to be long enough to reach your upper thread later — about 4 to 6 inches is standard. If the thread is too short, unwind a bit more from the bobbin before you insert it.
Reinsert the bobbin case into the machine
If you removed the bobbin case, slide it back into the machine with the thread tail pointing toward the back or side (depending on your machine's design). Push it in until you hear or feel a click — this means it is seated correctly. If your machine has a hinged door, close it gently until the latch catches.
Check that the bobbin case is fully inserted and level. A case that sits crooked or sticks out can cause the bobbin to jam or the thread to break during sewing. If it does not feel find, remove it and reinsert it.
Bring the bobbin thread up through the needle plate
With the bobbin case in place, you need to bring the lower thread up to meet the upper thread. Hold the upper thread tail in one hand and turn the handwheel (the large wheel on the side of your machine) toward you one full rotation. This motion lowers and raises the needle, which catches the bobbin thread and pulls a loop up through the needle plate — the metal plate under the needle with the hole where thread passes through.
After one full rotation, look under the presser foot (the metal piece that holds fabric in place). You should see a loop of bobbin thread. Use a seam ripper or small hook to pull this loop up through the needle plate hole. Pull gently until you have about 4 inches of bobbin thread above the plate.
Now you have both upper and lower threads above the needle plate. Hold both threads together and pull them toward the back of the machine, away from the needle. This prevents them from tangling when you start sewing.
Test the bobbin before you sew
Before you sew on your actual project, test the bobbin on scrap fabric. Place a small piece of fabric under the presser foot, lower the foot, and sew a few stitches. The stitches should look even on both sides — no loops, bunching, or loose thread on the bottom. If the stitches look wrong, the bobbin may not be threaded correctly or wound too tightly.
If you see loops or loose thread, stop and rethread the bobbin. Remove the bobbin case, check that the thread is seated in the tension spring, and make sure the thread is not twisted. Wind a new bobbin if the old one is wound unevenly or too tight. Bobbins that are overstuffed or wound at the wrong tension cause most lower-thread problems.
Troubleshoot common bobbin problems
If your machine skips stitches or breaks thread, the bobbin is often the cause. First, check that the bobbin is wound evenly and not too full. A bobbin that bulges or has thread piled on one side will not feed smoothly. Rewind it if needed.
Next, rethread the bobbin case. Remove it, pull the thread out, and thread it again following your manual's diagram exactly. Pay attention to the tension spring — the thread must sit under it, not over it. If the thread is not under tension, it will loop and create loose stitches.
If the machine still has problems, the bobbin case itself may be damaged. Look for dents, burrs, or rough spots inside the case. A damaged case can snag thread and cause breakage. If you find damage, contact the machine manufacturer for a replacement case — they are inexpensive and straightforward to swap.
Frequently Asked Questions
Can I use any bobbin in my sewing machine?
No. Bobbins come in different sizes and styles — some machines use class 15 bobbins, others use class A or class M. Check your manual or look at the bobbin case to find your machine's size. Using the wrong bobbin can cause it to jam or not fit in the case at all.
How tight should I wind the bobbin?
Wind it until the bobbin is full but the thread does not bulge or stick out past the edges. The thread should cover the bobbin evenly in a smooth, flat layer. If you wind too tight, the thread will break or create tension problems. If you wind too loose, the bobbin will not hold enough thread and you will run out mid-seam.
What if the bobbin thread keeps breaking?
Check three things: the bobbin is wound evenly and not too tight, the thread is seated under the tension spring in the bobbin case, and the bobbin case itself has no dents or rough spots. Also make sure you are using thread designed for bobbins — regular sewing thread can fray or break more easily in the bobbin case.
Do I need to rethread the bobbin every time I change the upper thread color?
No. The bobbin thread and upper thread are separate. You only need to rethread the bobbin when it runs out of thread or when you want to change the bobbin thread color. Most of the time you will just change the upper thread and rethread the needle.
Why does my machine make a grinding noise when I sew?
A grinding sound often means the bobbin is jammed or the bobbin case is not fully inserted. Stop sewing when ready and check that the bobbin case is seated all the way in and the latch is closed. If the case is in place, remove the bobbin and look for thread wrapped around the bobbin spindle or case. Clear any tangled thread and reinsert the bobbin.