Singer 401G Bobbin Case
 

Hi.

I`ve recently acquired a Singer 401 vintage sewing machine in good condition. I have cleaned it, and everything seems to be working as it should. However there is an issue with the upper thread getting caught and stuck UNDER the bobbin case itself. The case is an original 172082. I have attached a couple of photos. The first image shows what is supposed to happen, and the second and third images shows what is currently happening.

Is this simply a matter of a worn case? The case seems to sit a little to "high" in the machine which is why the thread gets caught.

There's a Facebook group that specializes in Singer 401 machines. Perhaps someone there could help. The group is named "Singer 401 Slantomatic".

Be aware that your G was made in Germany. It could be different from USA singers/ Welcome aboard.

Welcome to QB.

I'm wondering if one of the following would help. The service manual isn't real clear, but may help. Archaic Arcane has a series of which I'm doing a couple.
https://sewingdude.wordpress.com/201...ervice-manual/
https://archaicarcane.com/excuse-me-...have-the-time/
https://archaicarcane.com/the-looses...-thread-nests/
https://www.youtube.com/watch?v=lT98wbDLVco
https://www.youtube.com/watch?v=Rkl0xuD6C3E
https://www.youtube.com/watch?v=O7drU1gNKqo

Janey - Neat people never make the exciting discoveries I do.
Not affiliated with off-site link(s)

Welcome to the QuiltingBoard! I'm not sure what you mean by the case sitting high. If the case isn't properly seated the race/hook won't be able to turn freely around it. I see in picture #2 the left thread is not clearing the curved piece to the left of the feed dogs. Assuming the case is properly seated, I would look to see if this piece is bent down a little? Or if there's a burr or something under it catching the thread and not letting it move through as in picture #1. Also check all surfaces of the bobbin case for burrs as well as the inside of the race/hook area. I have a 401 within reach and will check the bobbin area to see if something jumps out at me.

I checked my 401, the needle thread is caught by the hook then pulled around on the inside of the race and the outside of the case along the back left quadrant then is pulled up over the case about the middle of the left side of the case as it is released from the hook. I used the service manual at Central Michigan Supply to check and adjust timing on mine, which I would do on yours along with checking all the surfaces along with proper seating of the case. The case should have noticeable wiggle when seated.

https://cdn.shopify.com/s/files/1/07...62061900659880

Check the thread clearance. You will find instructions for this adjustment at page 131 of the Service Manual.

It could be how the thread comes out of the bobbin. The direction. Good luck and let us know what you find.

Hi Mary. Welcome aboard.

I have a 401a. I found this video very helpful with thread problems. I had already cleaned the bobbin area when I found the video and I still got a lot of gunk out of it. The other thing is to make sure the bobbin case is seated properly.
bkay