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Your stone-skipping skills pale in comparison to this robotic rock launcher


What are the two things that all kids love? Rock skipping and robots, obviously. Using the kind of inventiveness that has made him a YouTube star, former NASA engineer-turned-quirky-inventor Mark Rober has combined both to put together a robot that’s able to skip rocks across the surface of water with impressive consistency. Best of all? It might even improve your own own rock-skipping technique so that this won’t join the growing number of fields in which robots put us on the unemployment scrap heap.

“I made a robot — or I suppose more of a machine, but ‘robot’ sounds way cooler — that could skip rocks really well,” Rober told Digital Trends. “Or, at least, it did eventually. We really just made it to have built-in adjustable parameters like wrist angle and arm angle so we could do experiments to find the best settings for a perfect rock skip.”

The robot was created by modifying a clay pigeon thrower, including the addition of customized wooden throwing arms, and a box base to give a bit more stability. The standardized rock replacement discs were air-dried clay, shaped with cookie cutters. Of course, the most important step was when Rober’s team of seasoned mechanics and engineers (read: his young nieces and nephews) stepped into the breach to give “Skippa” a spray paint and googly eye makeover, ensuring that it conformed to the necessary robot design stereotypes.

So what can we learn from the trial and error involved with getting Skippa to work? Mainly that the perfect rock skip involves rocks hitting the water at a 20-degree angle, with a 20-degree path, and a higher angle for cases when more energy is required. Flicking the wrist as much as is humanly (or robotically) possible is also a must. Oh, and the rock should be sufficiently heavy, with a flat bottom.

As much of a success as Rober’s rock-skipping robot is, however, he said he has no plans to elaborate on it in the near future. “I sort of pride myself on doing something totally different every month on my channel,” he continued. “Once I’ve visited a topic, I don’t ever really revisit it. My list of cool things I want to try is too long to allow for that.”

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