Bernina Bobbin Case Troubleshooting

Bobbins are the second most important thing on a sewing machine, secondary to none other than the needle and thread of course. These days bobbins are as advanced (some have sensor markings on them) as they machines that come with them. They can are made of mainly two materials, either plastic (usually clear plastic) or metal (older sewing machine models.) Bobbins are important because they allow for a stitch to be made on a fabric when the thread from the bobbin catches and interlocks with the thread from the needle into place. The bobbin is located and kept under the needle plate, under the needle plate is the bobbin mechanism consisting of the bobbin driver and hook (where the thread from the bobbin is caught and then let go when a stitch is made), the bobbin case (where the bobbin sits or is placed) and the bobbin (where the thread is wound and then released when sewing.) Today we’ll be looking at how to Troubleshoot (solve) some issues related to Bernina bobbin cases.

Table of Contents


The Bobbin Case Is Making Noise

This usually happens with typical Bernina bobbin cases, usually when the sewing machine is not computerized and the thread from the bobbin is about to finish, this will then cause the bobbin case to become unevenly balanced.

To Troubleshoot This

Stop the machine and re-thread the bobbin with thread as long as four inches then insert it back into the machine, this should solve the problem. It’s advisable to make use of bobbin winders atop most Bernina sewing machines when available for use.

Copper Wire Is Showing From Under Bobbin Case

When this happens it usually hinders the bobbin’s movement causing the bobbin thread to become a little tighter and less loose than usual. It also causes the thread from the bobbin to pucker (which means to enclose or fold over other pieces of thread causing it to become twisted and tangled.)

To Troubleshoot This

You have to put the copper back into its place with a gentle press or push using your finger. Under the bobbin case is a silver part which is called a backlash spring, this spring can backlash or error (moving the copper Wire from its place) when there isn’t enough tension on the bobbin a consequence of fast sewing. The copper wire should always be under the spring.


Bobbin Keeps Jamming

This may be caused by loosened threading making its way to the bobbin case area. Or the bobbin case being too big for the sewing machine it is put in.

To Troubleshoot This

You need to make sure that the thread from the bobbin is coming from the left (That is in an anticlockwise direction) so that the thread doesn’t end up rotating in the wrong direction and ultimately making its way to the bobbin case area. User manuals (from Bernina) are very helpful on particular things like bobbin case size for the sewing machine.

  • If loose threads or lint keep jamming the bobbin case area; it would be wise to use a vacuum cleaner, or compressed air, or small toothpicks, or a fine brush to clean out the loose thread and lint which may also solve this problem. At which point the bobbin case would need regular cleaning.
  • Another way to troubleshoot this problem is to make sure that the thread you’re using is for sewing machines and not hand sewing (sewing machine thread is stronger and thicker than hand sewing thread.) And that the thread is of a top quality (usually silky and glossy in appearance.) Low quality threads tend to leave a lot of lint (fluff or fuzz) around the bobbin case.


Bobbin Won’t Move At All

It’s one thing for the bobbin to jam, and an entirely different one when it stops completely. But it may be due to a couple of reasons, one being a fault on the bobbin driver’s gear mechanism.

To Troubleshoot This

Most people forget to oil their Bernina bobbin cases, this is one of the most important things to do to your sewing machine. Constant movement on the bobbin case’s part causes the oil to be used up quicker. Oil is important because it lessens the force of friction between the top surface of the bobbin driver and bottom surface of the bobbin case.

  • However if you oil the machine correctly and nothing seems to be happening, it would be best to take the entire machine to a professional sewing machine technician as the gears may be damaged.

Bobbin Thread Isn’t Coming Up

When you’ve inserted the bobbin into the bobbin case you should be able to grab the bobbin thread and (with aid from the handwheel) pull the thread gently towards you.

To Troubleshoot This

Make sure the bobbin driver’s hook has been pushed back to the left. Otherwise, when sewing the needle will not go down and pick up the bobbin thread.

More Troubleshooting

  • Most modern Bernina sewing machine models use a drop-in system for the bobbin (This as the name suggests allows you to drop your bobbin into the casing from the top.) As opposed to older sewing machine models that have a bobbin case with a front-loading system (usually metal bobbins.) It is important to make sure the bobbin is threaded according to a manual’s exact specifications.
  • On the bobbin driver is a hook that allows for the successful capture of the bobbin thread, it is important to inspect the hook on a weekly basis to make sure there are no sharp ridges, dents or punctures. It may be causing breakage on the part of the bobbin thread.
  • When the needle is constantly punching up-and-down it often hits the bobbin case area and leaves marks (most often on drop-in system sewing machines), especially if the machine needs to be serviced accordingly.
  • You can gently polish the bobbin driver hook with fine sand paper to rid it of most, if not all, of the dents and sharp ridges.