I liked the setting, perhaps because I've been doing welding and electrical stuff recently. Incidentally, she wasn't "machining" the part but grinding it (on a bench grinder). I don't know if grinding a part to fit by hand like that would count as machining, typical machining means lathes, mills, CNC machines. Almost decided to study machining but decided on electrical instead...
You don't see much blue collar stuff, except "Lonely Wolf, Lonely Sheep". It would have been more interesting if Madoka had decided to train Mei in that sort of work. It's the backside of everything, really, though more people work in the service industry everything (cars and computers and everything) has to get made somewhere.
Well, I guess it wasn't going to go anywhere, so whatever. But I would have liked to have had something.