It looks like the inner workings of an elaborate mechanical clock, but it's actually one of many hypnotic kinetic sculptures created by Connecticut-based artist and woodworker David C. Roy over the years. And they can run anywhere from five to 40 hours on a single wind, a testament to their excellent design.
Just to get the obvious question out of the way: no, it's not a perpetual motion machine. ("Don't I wish!" Roy writes on his FAQ.) The sculptures must be wound regularly. Each machine relies on a constant force spring, which — as the name implies — exerts a constant force over its range of motion. (In that respect, it doesn't follow Hooke's Law, which says that a spring's force is proportional to its extension.) Some of Roy's earliest sculptures employed a suspended weight to induce the motion, much like a pendulum clock.
The sculptures don't make good clocks, however, even though they look a bit like clocks and rely on a similar mechanism. "They are escapements," Roy explains. "The difference is my escapements divide time into fairly large and sometimes random chucks." And that's not good for keeping accurate time.
Roy's interest in mechanics and motion comes naturally, given his background in physics and engineering. His father was an engineer who worked on jet engines, and the two shared a love for the space program. At first Roy studied engineering with dreams of being an inventor, then switched to physics, earning his degree from Boston University in 1974.
He credits a high school friend who studied at the Rhode Island School of Design with speaking his interest in creating art. "I saw it as another type of creative problem solving, not all that different from my advanced physics courses, but with a completely different goal," he writes. "To this day, I find art and science to be closely linked. He taught himself wood-working, and has been a full-time sculptor since 1975.
You can see one of his sculptures, "Dimensions," in action below; its spring-driven mechanism is capable of running 40 hours on a single wind.
Check out more of David C. Roy's work at his Website, or see more sculptures in action at his YouTube channel.
Images and video: David C. Roy/Wood That Works.