I seem to have a new Bernina in my future, and it came without a bobbin case. So I went online on Amazon and Ebay to shop.
The same companies sell on both, the prices are the same.
The one on the left came with my original 140 Activa machine.
The one on the right was the unbranded online purchase.
Unbranded has a thinner arm for thread, and a tension screw of same metal as case (original has a darker metal screw)
There are more metal working marks, but that's immaterial.
Hole is at about the same angle from the body.
The thread hole in the arm is a little bigger. Since many bobbin cases don't have that hole, that's fine.
This is where my issues come in. The side opening on the metal spring on the side (which is how you are adjusting the thread tension) is kinda outta whack.
This is the original. All lined up nice
And this is the online purchase. The opening between the prongs is smaller, the 'tension spring' isn't lined up in the middle.
I could test it, and I probably will, but I've got a stack of real sewing to do and not a lot of play time.
It was about ten dollars, but I could have spent between 5 and 20 for the same model from various sellers.
So I'm glad the repair shop talked me into buying a branded one. I mean, I'm cheap thrifty, but dang.