The sewing machine stopped sewing.
Irritating.
It was belting lines of holes in the cloth, but not leaving thread in them.
Struggled with it for hours.
Eventually discovered that the bobin wasnt turning quite far enough.
A grub screw had slipped.
Im not a sewing machine engineer.
I struggled fixing it.
The loose grub screw was to the left of the bottom end of the pipe
I twisted it straight and did it up and was able to carry on sewing.