I never really paid attention to this thread and sure didn't think I'd post to it but, funny old life. A couple years ago my wife bought a sewing machine and table, from a friend, that could be used to repair horse blankets (horses destroy all horse blankets). I didn't pay much attention to it as we are still deciding where to set up that "shop" area. I was recently inspired to uncover it and pay attention. Turns out it's a Singer 96-10 manufactured in December of 1920. Still in great shape and, relatively, lightly used for the past 100 years. Being an engineer, I've found it very interesting. I now understand how the sewing process works, hook alignment, thread tensions, stitch length adjustments, clutch motors, knee lifters for the foot, etc. And, since I'm fine with making my own camping gear, I'll probably use it. First job is to clean the clutch motor (too grabby) and then slow the whole thing down - currently top speed is around 2200 stitches/minute. I cannot even think that fast.
Oh, that thread on the top is just wound that way to keep it out of the way as I'm cleaning and inspecting. I know the routing is "not quite right".