How a sewing machine hooks threads into your fabric

EDIT: Apologies for the mediocre quality of the video - I originally made this to answer questions for a couple people commenting on an image. I never thought I would have thousands of views, or else I would have spent more than 20 minutes making this! I'm glad to know that people are finding it useful. :)

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How does it work? Several people mentioned that they had seen this image: http://imgur.com/gallery/vThii but could not understand what was going on and needed to see it "in real life".
Explains where the bobbin thread sits, how to thread an ancient Kenmore sewing machine, how the spool thread catches the bobbin thread.

Hopefully this clears up some questions.