Trouble with old sewing machine

[JEmmelkamp]

Hello Stefano
I think I can help you with the sewing machine. I used to work with a carpet binding machine which looked very similar to this one.
First the threading is not correct. Go from the spool on top of the machine to the guide on top rear at the left end as in picture #1. From there down between the tension disks from the back and up inside the curved guide Then go through the thin spring. Next go through the tension lever that goes up and down (from the back to the front), then down through the guide loop on the end plate.The thread then goes down through the guide on the top of the needle and straight down to the needle passing through it from left to right.

When the needle goes down through the material it must go low enough so that the eye of the needle goes below the the point of the shuttle (shuttle hook). Looking at picture # 7 and assuming that the needle is still coming down and that the shuttle hook is still moving to the left then all is good. The shuttle has to rotate further to the left and the needle must come down more. (The space between the needle and the hook in this picture should be about the thickness of a strip of paper … almost touching)
.Picture #8 shows the needle and shuttle in the correct positions assuming that the needle is starting up and the shuttle is starting to rotate to the front. The material you are sewing holds the thread as the needle starts to go up. This makes the loop of thread beside the needlet that the shuttle hook has to catch as it comes forward.
Picture #10 shows this correctly.
The shuttle must now rotate to the left until the loop in at the bottom as in picture # 11. This is when the tension lever above quickly jerks the thread up the rest of the way around the bobbin holder and up through the space in the shuttle race and then up tight against the back in the material. If the timing is not correct (needle does not go far enough down or the shuttle hook does not go far enough back) then you will not get a stitch.