Landbeest, A Single Servo Walking Robot

Walking robots have a rich history both on and off the storied pages of Hackaday, but if you will pardon the expression, theirs is not a field that’s standing still. It’s always pleasing to see new approaches to old problems, and the Landbeest built by [Dejan Ristic] is a great example.

It’s a four-legged walker with a gait dictated by a cam-and-follower mechanism that allows it to perform the full range of leg movement with only one motor. Each cam can control more than one leg in synchronisation, and in his most recent prototype, there are two such mechanisms that work on opposite corners of a four-legged machine. The legs are arranged in such a way that the two corner-to-corner pairs pivot at their centres in a similar manner to a pair of scissors; allowing a servo to steer the robot as it walks.

The result certainly isn’t as graceful as [Theo Janssen]’s Strandbeest, from which it evidently takes inspiration for its name, but it’s no less capable for it. After the break you can see a video he’s posted which clearly illustrates its operation and demonstrates its ability to traverse obstacles.

The only thing that’s missing are the files and software should you wish to create your own. He’s unapologetic about this, pointing out that he’d prefer to wait until he is satisfied with it before letting it go. Since he’s put a lot of work in so far and shows no sign of stopping, we’re sure he’ll reach that point soon enough.

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Crawling PCB ‘Bot Is Flexible Where It Counts

20 years ago, PCB production was expensive and required a multitude of phone calls and emails to a fab with significant minimum order restrictions. Now, it’s cheap and accessible online, which in addition to curtailing the home etching market has created significant new possibilities for home projects. Now that flexible PCBs are also readily available, it’s possible to experiment with some cool concepts – and that’s precisely what [Carl] has been doing.

The aim is to build a walking robot that uses actuators made from flexible PCBs. The flexible PCB is printed with a coil, capable of generating a small magnetic field. This then interacts with a strong permanent magnet, causing the flexible PCB to move when energised.

Initial attempts with four actuators mounted to a 3D printed frame were unsuccessful, but [Carl] has persevered. With a focus on weight saving, the MK II prototype has shown some promise, gently twitching its way across a desk in testing. Future steps will involve building an untethered version. This will replace the 3D printed chassis with a standard fibreglass PCB acting as both control board and the main chassis to minimise weight, similar to PCB quadcopter designs we’ve seen in the past.

We can’t wait to see the next revision, and if you’ve been working on your own walking robots, make sure you let us know.

Move Over Strandbeest, Here’s Strider!

Father-and-son team [Wade] and [Ben Vagle] have developed and extensively tested two great walker designs: TrotBot and the brand-new Strider. But that’s not enough: their website details all of their hard-earned practical experience in simulating and building these critters, on scales ranging from LEGO-Technic to garage-filling (YouTube, embedded below). Their Walker ABC’s page alone is full of tremendously deep insight into the problem, and is a must-read.

These mechanisms were designed to be simpler than the Jansen linkage and smoother than the Klann. In particular, when they’re not taking a stroll down a beach, walker feet often need to clear obstacles, and the [Vagles’] designs lift the toes higher than other designs while also keeping the center of gravity moving at a constant rate and not requiring the feet to slip or slam into the ground. They do some clever things like adding toes to the bots to even out their gaits, and even provide a simulator in Python and in Scratch that’ll help you improve your own designs.

If you wanted a robot that simply moved, you’d use wheels. We like walkers because they look amazing. When we wrote [Wade] saying that one of Trotbot’s gaits looked animal-like, he pointed out that TrotBot got its working name from a horse-style gait (YouTube). Compared to TrotBot, the Strider family don’t have as much personality, but they run smoother, faster, and stronger. There’s already a 3D-printing-friendly TrotBot model out there. Who’s going to work something up for Strider?

How much do we love mechanical walkers? Enough to post about bicycles made with Jansen linkages, remote-controlled toy Strandbeests both with weaponry and without, power-drill-powered walking scooters, and of course basically anything that Theo Jansen is up to.

If a trip to [Wade] and [Ben]’s website doesn’t get you working on a walker project, physical or virtual, we don’t know what will.

(And from the editorial department of deconfusion: the image in the banner is TrotBot, but it was just too cool to not use.)

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Hackaday Prize Entry: Two Leg Robot

If you’re working on your own bipedal robot, you don’t have to start from the ground up anymore. [Ted Huntington]’s Two Leg Robot project aims to be an Open Source platform that’ll give any future humanoid-robot builders a leg up.

While we’ve seen quite a few small two-legged walkers, making a pair of legs for something human-sized is a totally different endeavor. [Ted]’s legs are chock-full of sensors, and there’s a lot of software that processes all of the data. That’s full kinematics and sensor info going back and forth from 3D model to hardware. Very cool. And to top it all off, “Two Leg” uses affordable motors and gearing. This is a full-sized bipedal robot platform that you might someday be to afford!

Will walking robots really change the world? Maybe. Will easily available designs for an affordable bipedal platform give hackers of the future a good base to stand on? We hope so! And that’s why this is a great entry for the Hackaday Prize.

Hackaday Prize Entry: Staircane, A Walker That Takes The Stairs

[Jim]’s aunt has lived in the same house for the last 50 years. She loves it there, and she wants to stay as long as possible. There’s a big problem, though. The house has several staircases, and they are all beginning to disagree with her. Enter Staircane, [Jim]’s elegant solution that adds extendable legs to any standard walker.

Most of the time, walkers serve their purpose quite well. But once you encounter uneven ground or a staircase, they show their limitations. The idea behind Staircane is a simple one: quickly extend the back or front legs of a walker depending on the situation, and do so in unison. Staircane uses one button for each set of legs. Pushing the button engages a thin cable, much like the brake cable on a bicycle. The cable pulls a release trigger, unlocking the notched extensions. When the legs are sufficiently extended, the user simply releases the button to lock them in place. Once on flat ground, the user pushes the button again while pressing down on the walker to even out the leg lengths. Check out the video after the break to see the 3D-printed prototype.

Staircane is a semi-finalist in our Wheels, Wings, and Walkers challenge, which ended a few weeks ago. Did you know that you can enter your project into more than one challenge? Since this project falls squarely into assistive technologies territory, we hope that [Jim] and his team submit Staircane to our Assistive Technologies challenge before the deadline on September 4th. We don’t have many entries so far, so if  you’re thinking about entering, give in to temptation!

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Hackaday Prize Entry: Octo, The Robotic Walker

Walkers like the Strandbeest are favorites due in part to their smooth design and fluid motion, but [Leandro] is going a slightly different way with Octo, an octopodal platform for exploring rough terrain. Octo is based on the Klann linkage which was developed in 1994 and intended to act as an alternative to wheels because of its ability to deal with rough terrain. [Leandro] made a small proof of concept out of soldered brass and liked the results. The next version will be larger, made out of aluminum and steel, and capable of carrying a payload.

The Strandbeest and Octo have a lot in common but differ in a few significant ways. Jansen’s linkage (which the Strandbeest uses) uses eight links per leg and requires relatively flat terrain. The Klann linkage used by Octo needs only six links per leg, and has the ability to deal with rougher ground.

[Leandro] didn’t just cut some parts out from a file found online; the brass proof of concept was drawn up based on an animation of a Klann linkage. For the next version, [Leandro] used a simulator to determine an optimal linkage design, aiming for one with a gait that wasn’t too flat, and maximized vertical rise of the leg to aid in clearing obstacles.

We’ve seen the Klann linkage before in a LEGO Spider-bot. We’re delighted to see [Leandro]’s Octo in the ring for the Wheels, wings, and walkers category of The Hackaday Prize.

Watch The ClearWalker Light Up And Dip Its Toes

[Jeremy Cook]’s latest take on the Strandbeest, the ClearWalker, is ready to roll! He’s been at work on this project for a while, and walks us through the electronics and control system as well as final assembly tweaks. The ClearWalker is fully controllable and includes a pan and tilt camera as well as programmable LED segments, and even a tail.

When we last saw [Jeremy] at work on this design, it wasn’t yet functional. He showed us all the important design and assembly details that went into creating a motorized polycarbonate version of [Theo Jansen’s] classic Strandbeest design; there’s far more to the process than simply scaling parts up or down. Happily, [Jeremy] is able to show off the crystal clear beauty in his photo gallery as well as a new video, embedded below.

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