Meet the mechanical dog that can take on Boston Dynamics

YouTube star James Bruton has made his very own mechanical dog. The open-source design means you’ll be able to follow in his footsteps and create a bargain-basement Boston Dynamics alternative.

Boston Dynamics hit the headlines again this week with their frankly terrifying twerking and moonwalking mechanical dog, Spot Mini. It’s staggering just how far robots made by the company have advanced in just a few years, but the US giants aren’t the only one making innovative canine robots.
YouTube star and robotics expert James Bruton has spent the past few months creating his own homemade alternative, openDog. And as the name cunningly hints, Bruton has designed his mechanical pooch to be entirely open-source, including hardware and software – meaning you’ll be able to follow instructions and make your very own robotic best friend. We’ve been chatting to Bruton to find out more.
openDog’s story actually predates YouTube, with Bruton tinkering with tech ever since he was a child. “The brief recent history is that somewhere around 2004 I wanted to build a human-sized walking robot,” Bruton explains. “I couldn’t find anything online explaining how to do it, so I decided to work it out and write about it.
“I did make some videos which I uploaded later to YouTube, but most of these robots are made of wood and wiper motors, and about 5ft [1.5m] tall. A few years later I made an Iron Man suit and some other props that became popular on YouTube and a lot of the previous projects are generally movie robots like BB-8 or Bender from Futurama, which I built on top of the latest bipedal robot (version 10).”

Bruton was on a roll, but his walking bipedal robot did have some limitations, and he decided to design a new open-source robot from scratch – leading to the creation of openDog. Unlike his previous robots, Bruton put a lot more effort into the design stages of openDog, and aimed to improve on the range of motion on offer.
“Most of the forward planning for openDog was to make sure that the inverse-kinematic model could be solved,” Bruton explains. In short, the aim was to ensure that openDog would be able to move as efficiently as possible.
“If I just made it up as I went along, there would have been too many unknowns in my geometry, so I could never work the angles back. However that’s as far as I planned it, so the rest needs to be developed now. I don’t see too many hardware changes, but it’s quite modular anyway for minor tweaks.”

The result is a design that looks incredibly complicated to our eyes, but the theory of which is actually quite simple. A host of brushless motors and ball screws actuate openDog’s joints and make it possible for the legs and body to move in a surprising number of different directions.
“I probably can’t improve on Boston Dynamics,” admits Bruton. “And from a hardware point of view my design is worse – although in the course of building it there will be other spin-off projects including ‘openJumpy’ (a separate leg development) and maybe another robot.”
While openDog may lack the ultimate polish of Spot Mini, Bruton does go one better in a couple of different areas. Not least the fact it hasn’t taken tens of millions of dollars to develop, and the open-source nature means that you’ll be able to follow in Bruton’s footsteps and build your own version.
“I guess openDog’s main purpose is to make the YouTube series and explain everything along the way, which allows people to appreciate the work that goes into the Boston Dynamics Spot Mini and other robots. Ultimately, I’m an almost-full time YouTuber, which is a bit of a fantasy job. So I guess it’s somewhere between doing the projects I want to do and finding the ones that people will watch. I’m not the most viral channel, but I seem to have a balance and I feel I push my skill set in the builds, rather than just smash things up with themed hammers.”

It’s easy to see the incredible amount of work that’s gone into developing openDog, but it’s also worth remembering that Bruton faces a host of different challenges to the likes of Boston Dynamics. “I suppose ultimately my limitations are budget to a certain extent, although having a large following helps with YouTube and Patreon earnings,” Bruton adds. “So far the hardware cost of openDog is around £2,000 [€2,275] – so pocket change compared to the money Boston Dynamics spend on resources and people. Also, there’s only one of me.”
One of the biggest challenges for Bruton was developing the software for openDog, and he explains: “I’m not really a software developer, but in principle I know what needs to be done – it’s just a case of getting that into code that works. A few people have said they want to contribute at a later stage when we get to navigation and higher level AI tasks. But so far I don’t recommend anyone else build the hardware, at least until I can make it walk, which is going to take quite a bit more development. For now, the future plans are to stick with the hardware I have and make it walk properly.”
In the meantime, we suggest you sit back, watch and enjoy the show. And when Bruton does finally master the walking process, look forward to creating your very own robotic friend. It may even be able to pull off some fancy dance moves, with Bruton concluding: “I think I could fluke most of the moves that Spot Mini does in that video, although it’s probably not repeatable…”