If you've ever shuddered at the sound of the gears grinding on your car's manual transmission, you might have a hard time watching this video. But don't dismay, as these three gears spinning at 4,500 RPM come in and out of sync with each other, at no point do they ever interfere or grind against each other.

The somewhat stressful demo was created by Mitsubishi Electric as a way to show off its precision control systems that are able to keep multiple motors in perfect sync, at speeds up to 6,000 RPM, without nary a concern about these gears interfering with their neighbor.

And besides attracting a crowd at a trade show, the demo highlights a neat system where multiple gearing systems could actually share their kinetic energy. As one brakes, its energy could be passed to another gear similar to the approach used in regenerative braking systems on electric cars to reduce wasted energy. [DigInfo TV]