Wow, while reviewing the history of the sewing machine to teach my 8th grade, I came upon this which really is great to understand how a sewing machine works...but alas, we do not use videos in a Waldorf methods school, but I think between my drawings and our "Human Sewing Machine" , plus taking a machine apart, they get it....
http://www.youtube.com/watch?v=ML8CMNzW6Tg&feature=related
pretty cool!