This is a very long series of short animation clips, showing a great variety of linkages and other mechanisms. Fun to watch, but it will tend to eat up some time, because it can become quite addicting!!! PS - The first of these is from 11/27/13, and the last one (currently) is from 11/14/16. Who knows how many he will be adding more as time goes by.
(Thanks to Rick Sparber for sending me the link)