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How Sphero created the best R2-D2 toy ever released

Behind the scenes with the $179.99 robot


Star Wars toys are announced during a special event called Force Friday that takes place a few months before the release of each movie, and robot company Sphero had two big surprises for fans this year.

One was a robotic BB-9E, a seemingly dark-side version of the lovable droid from the The Force Awakens. The second was a $179.99 robotic R2-D2 that promised to bring the character home in a way no other toy had been able to achieve.

So what does it do that’s so special, and how were they able to pull it off? We called Adam Wilson, chief scientist and co-founder of Sphero, to find out.

It’s all in the legs

R2-D2 delivers the basic features you’d expect in this sort of robot. He lights up, and the head swivels around to “look” at the environment. He delivers those destinctive beeps and boops through an internal speaker, and his movement is controlled through a smartphone app.

The toy itself feels surprisingly light when you pick him up, and it’s detailed enough that it looks great on your desk or shelf as a display.

But you’ll see what makes this R2-D2 special the moment you open the app. R2’s third leg slides out from his body and the robot leans back to roll forward and turn. The whole motion looks fluid and effortless. The leg retracts when R2 stops moving, so it can stand up straight. The toy can also shift its weight between his legs to do a sort of waddle, a movement instantly recognizable to anyone familiar with the films.

That leg was always important to the design of this robot.

“It was a core idea,” Wilson explained. Sphero researched other R2-D2 toys and even looked at builder’s groups online to see how many had to be able to do it well. The answer was not many.

“It’s a challenge to do, at the very beginning it was like if we can pull this off, it will be a hit,” he said. “Otherwise it will be just like every other R2-D2 that you can buy.”

Fitting all the mechanical parts inside the toy’s shell as well as the electronics proved to be a challenge, but so did figuring out how to make him move and react to the environment in a way that felt like the the real thing. Sphero has a hidden advantage when it came to getting the lights, sounds and movement to all work together in a natural way.

“We have this tool we call robot animator, it’s very unique and special to our robots,” Wilson told Polygon. The company creates a 3D model of the robot in the program with all the advantages and limitations of the hardware used to create the real thing, and then they get to work.

“We have all these neat tools that turn whatever the animation does on the screen into a robot motion, with all the constraints of physics and real life going into that,” Wilson said. “We let animators make it, not programmers.”

And it took a lot of hardware to get those animations to work in the physical robot, which proved difficult during the design phase.

“To fit all of the mechanics as well as the electronic circuits in there was a super challenge, there’s also the speaker and the noise, it was a challenge,” Wilson said. “Just finding the space to put anything. The next would be the feet.”

The art of the waddle

R2-D2’s feet don’t seem like they would be a technical challenge, but the character uses them for a lot onscreen. He rolls and turns, but he also waddles from time to time to express emotion.

The R2-D2 robot does the same thing on command, a sort of nervous shuffling motion as the character shifts weight from foot to foot when he’s standing on two legs and the third leg is pulled back into the body.

“If you look down at the feet, there are these sort of little ankles and there are motors down that that control how he drives, but also how he waddles,” Wilson explained.

There’s even a command that tells him to stop and shuffle for a moment, and then you hear an internal “explosion” as he falls over as if broken.

Sphero was used to making toys that were safe for even rowdy children, so it knew how to make the fall itself safe, and the animation tool allowed them to program the movement so it worked well every time.

“Within that robot animator tool, we can set parameters,” Wilson said. “One we set is that we want him to stay at a certain angle, to stay upright. We tell it not to let yourself move so fast that you tip over. We’re able to also overwrite those, so that we just told him to waddle back and forth and then at the very end we’re able to overwrite the robotic stabilization and he falls over.”

It’s the rare toy robot that comes complete with its own pratfall.

The animation tool allows Sphero’s animators to perfect the movement and animations of the toy. Sphero sent me one of the robots to try in my own home, and it’s just as cool in action as it looks in the trailers and videos.

He zips around the house under his own power or under the control of the app, and it was fun getting him to play with our younger children and cats. His movement is so smooth and his pre-programmed reaction moments are so true to the movie that it’s hard to look at other R2-D2 toys after you get used to playing with this one.

$179.99 is expensive for a toy but affordable for a robot, which puts this R2-D2 at a somewhat awkward price in the market. The company is aware of that tension.


“You always have to make this tradeoff between price and features. Like everybody wants an R2-D2 that has a jetpack in it and can fly, right?” Wilson said with a laugh.

It’s a delicate balance to try to hit.

“It’s not seen by the customer, but most of our decision time and a lot of our effort goes into determining what would be the best, and what’s too much,” he continued. “It’s like a craft, finding just the right amount of spices to make just the perfect one. You can always overdo it. You can make a product too crazy, and you can make a product not crazy enough.”

The packaging conveys the idea that this is a deluxe product. There’s a slightly magical feeling to how the box presents R2-D2 to you when it’s first opened, and the included micro-USB cable for charging even matches the gold-colored piping on R2’s feet. I’ve shown the robot to a number of people, and everyone has been delighted when they watch it extend its third leg before taking off.

Sphero is clearly comfortable moving past creating robot balls at this point, and I wanted to know what character the company would love to tackle next if they could pick anything from pop culture.

Wilson didn’t even pause. “I would want to make Johnny-Five and have someone remake Short Circuit,” he said.

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