Here is another graceful and compelling wall-mounted kinetic sculpture by David C. Roy. This one is titled Variation II Wave.
From the artist's web site:
Variation II Wave is the result of applying what I've learned mechanically to the Variation concept. The mechanism is a single spring drive that delivers about 15 hours of run time. Part of the efficiency is due to a better use of bearings and part to how the mechanism itself is balanced.
Here is where you can learn more about Variation II Wave by David C. Roy.