If you want a grandfather clock made out of Legos, then visit ericharshbarger.org/lego/clock.html. You will find a detailed account of how Eric Harshbarger built his (somewhat) running timepiece, including the mechanism that makes it (somewhat) run, and the various mechanisms he has tried on his way to discovering this one. If, however, you prefer grandfather clocks made out of things like wood, with more reliable timekeeping abilities, then visit 1-800-4Clocks.com.