Here's an excellent video explaining, in slow, clear German, how a sewing-machine works. A good opportunity to practice some of the names of the parts.
How cool! Thanks for that. I have a 1940s Elna Grasshopper (and I even have those snippy scissors). It has never been serviced; I inherited it from my mother and have been sewing with it for decades. It still runs like a Swiss watch!
I can"t sew and don't have a machine but when I was in a local market in Dar in Tansania they had one floor with nearly only old sewing machines. It was so nice. I was even tempted to buy one. Really beautiful ones.