Bob - nicely done. It's amazing how long these things will go once they get started. I notice you have it clamped to the table - do you plan to make a heavier base?
Note to Ken: I've never made one of these, so I am just guessing here, but it looks to me like your design has too much mass in the pendulum "rod" and not enough in the "bob." No doubt bearing friction is also a factor; ball bearings must certainly be a big benefit, if not a requirement (at least for a small version). Let us know if you get it working.