Good vs. Bad Bobbins
This Featherweight Hint is all about bobbins. What type do you have in your machine? After reading this post, it might be a good idea to double check your supply, or at the very least make sure you know the source for your Featherweight Bobbins.
A couple of weeks ago we had a machine come into the shop that had a bobbin case jammed onto the machine. The cause was a poor quality bobbin. It can be hard to tell the difference sometimes between good and bad bobbins, so it’s best to always know and buy from a reputable Featherweight dealer. Bad bobbins found on the market today are almost always the ones you will see pre-packaged in sewing or craft stores.
They look kind of like these:
Pre-packaged Featherweight bobbins are not recommended!
I am certain the company that makes them means well and they may not even be aware that the manufacturing process for their bobbins is so inconsistent, but let this be a caution to you. Bad bobbins can jam the bobbin case onto your machine. Trying to force the bobbin case off can result in a broken bobbin case, which can be pretty expensive to replace with an original.
So, how do you tell a good bobbin from a bad one? That’s a really good question! If the bobbins are still in their tidy packages like those above, that’s easy to tell the difference. Don’t buy or use them! If the bobbins are scattered and loose in your attachments box or machine case, then telling the difference can be a bit tricky or a wild guess. Usually, they are a bit thicker when inserted into the bobbin case…. however, that always isn’t a foolproof test either. I’ve found some good vintage bobbins that are thicker and they fit just fine.
The real issue lies with the bobbin in the bobbin case and then on the post on the bobbin case base.
How does the bad bobbin cause the bobbin case to jam?
If when putting the bobbin case (with a bobbin inside) on the machine and the latch does not snap closed, then the center of the bobbin is too thick and will not allow the latch to secure over the bobbin case base post.
The pre-packaged bobbins are thick in the center where the post of the bobbin case base goes through it. When the bobbin case goes onto the machine, the hole in the center of the bobbin case latch goes over the post in the center of the bobbin case base. If the bobbin is too thick, the latch will do one of two things: 1.) not allow the bobbin case to go on all the way (with the latch securing it), or 2.) if you are able to get the bobbin case on all the way, the latch will be so tight over the bobbin case base post that it will not slide to the open position allowing the bobbin case to be removed. If this happens, usually the latch is broken off the bobbin case from too much force when trying to remove it. The replacement latches we sell are almost always sold due to a bobbin case being stuck on a machine caused from poorly manufactured bobbins.
In the event that you do get a bobbin case jammed onto your machine, all is not lost…. take a deep breath and gently press with a small screwdriver where you see the arrow in the photo below (and pressing in the same direction as the arrow). This will usually move the latch over so that it will release off the center pin. Whatever you do, don’t force anything. If you try to force the jammed bobbin case off by pulling the latch too hard, the latch will usually snap off.
(Sidenote: Coincidentally, reproduction bobbin cases can result in jammed bobbin cases, too. We quit carrying the replica bobbin cases several years ago. Although they look very much like an original there are enough variances and manufacturing flaws that they rarely work well. Be very careful when purchasing one — make sure it is guaranteed by your seller and fully tested.)
Many thanks to our friend, Tom Motter, for his work in measuring bobbin thicknesses. Because the inferior bobbins are almost indistinguishable from the proper-fitting bobbins to the naked eye, Tom has provided the range of measurements for bobbins that do work using his machinist’s micrometer. Proper-fitting bobbins will have a maximum thickness of 0.300 inches. Nevertheless, the information of getting your bobbin case off the machine (if stuck from a bad bobbin) is still relevant because most Featherweight owners do not have such a tool for measuring.
In conclusion, buy good bobbins from reputable Featherweight dealers and if your bobbin case is missing, always seek an original. We carry original bobbin cases here and good bobbins here and here. We have made it a habit over the years to test batches of bobbins in our shop just to make sure that manufacturing remains consistent and that they will be safe for our beloved vintage Featherweights. Even my wife uses them in her Featherweight 221 and 222K Sewing Machines.
Just like the vintage original bobbins, we know these new Featherweight bobbins will eventually be passed down with your machine and they need to work well for many generations.
Good Featherweight Bobbins