Stepper motor part starts at about http://www.youtube.com/attribution_link?a=eXhUlW5Hzo8&u=/watch?v%3D5thxBgew7N0%26feature%3Dshare&t=2m50s…
Found this interesting. Knew most of it already, but still good info…
http://www.youtube.com/attribution_link?a=eXhUlW5Hzo8&u=/watch?v%3D5thxBgew7N0%26feature%3Dshare