Robots Hacks

2348 Articles

A Walking Robot With A Single Servo

September 16, 2020 by 13 Comments

We’ve all been there — you see somebody do something cool on YouTube and you just have to give it a go. For [lonesoulsurfer], the drop-everything-and-build happened to be a little four-legged walker robot that runs on a single servo. Though it may be simple, there really is nothing like seeing a robot you created take its first steps.

[lonesoulsurfer]’s walker is made mostly from scrap aluminium and other scavenged parts like coat hangers, paper clips and the metal bits and bobs from banana jacks. The Dremeled and bent body would likely be the hardest to imitate for a first-time builder, but any sturdy chassis that allows for things screwed and bolted to it should work. Also, don’t expect it to work right away. It will take a bit of tuning to get the gait right, but it’s all part of the fun. So is modifying a 180° servo for continuous rotation.

We really like the way this robot walks — it saunters around like a long bulldog and looks like it can handle almost any terrain. Watch it walk after the break, and stick around for the build video.

There’s just something about simple robots without microcontrollers. If you’ve never heard of BEAM robots, cut your teeth on this ‘bot with circular legs.

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Open-Source Robotic Arm For All Purposes

September 15, 2020 by 23 Comments

A set of helping hands is a nice tool to have around the shop, especially if soldering or gluing small components is a common task. What we all really want, though, is a robotic arm. Sure, it could help us set up glue or solder but it can do virtually any other task it is assigned as well. A general-purpose tool like this might be out of reach of most of us, unless we have a 3D printer to make this open-source robotic arm at home.

The KAUDA Robotic Arm from [Giovanni Lerda] is a five-axis arm with a gripping tool and has a completely open-source set of schematics so it can be printed on any 3D printer. The robot arm uses three stepper motors and two servo motors, and is based on the Arduino MEGA 2560 for control. The electrical schematics are also open-source, so getting this one up and running is just an issue of printing, wiring, and implementing some software. To that end there are software examples available, and they can easily be modified to fit one’s robotic needs.

A project like this could be helpful for any number of other projects, or also just as a lesson in robotics for yourself or even in a classroom, since many schools now have their own 3D printers. With everything being open-source, this is a much simpler endeavor now than other projects we’ve seen that attempted to get robotic arms running again.

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A Tentacle That’s A Work Of Art

September 15, 2020 by 8 Comments

We all bring our own areas of expertise to our work when we build the projects that find their way in front of Hackaday writers, for instance a software developer brings clever brains to their microcontroller, or an electronic engineer might bring a well-designed piece of circuitry. [Yvo de Haas] is a mechanical engineer, and it’s pretty clear from his animatronic tentacle that he has used his expertise in that field to great effect.

If you think it looks familiar then some readers may recall that we saw a prototype model back in February at Hacker Hotel 2020. In those last weeks before the pandemic hit us with lockdowns and cancellations he’d assembled a very worthy proof of concept, and from what we can see from his write-up and the video below he’s used all the COVID time to great effect in the finished product. Back in February the control came via a pair of joysticks, we’re particularly interested to see his current use of a mini tentacle as a controller.

At its heart is a linkage of 3D-printed anti-parallelograms linked by gears, with cables holding the tension and controlling the movement of the tentacle from a set of winches. The design process is detailed from the start and makes a fascinating read, and with its gripper on the end we can’t wait for an event that goes ahead without cancellation at which we can see the tentacle for real.

If you’d like to see more of [Yvo]’s work, maybe you remember his wearable and functioning Pip-Boy, and his working Portal turret.

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Budget-Friendly Bend Sensor Deforms With Precision

September 14, 2020 by 5 Comments

We’re pretty familiar with budget resistor-based bend sensors at this point, but this sensor is in a totally different class. Instead of relying on resistive elements, [Useok Jeong] and [Kyu-Jin Cho] devised a bend sensor that relies on geometric properties of the sensor itself. The result is a higher-fidelity measuring device made from a pretty widely available collection of stock parts.

We’ll admit, calling this device a bend sensor might be a bit of a stretch, so let’s dig into some of the operating principles. What we’re actually measuring is the accumulated angle, the sum of all the curvature deformations along the length of the sensing element. The sensor is made of 3 main pieces: an outer extension spring-based wire sheath; a flexible, tensioned inner wire core that’s fixed at one end; and a small displacement sensor that measures the length changes in the wire’s free end. The secret ingredient to making this setup work is a special property of the outer wire sheath or spring guide. Here, the spring guide actually resists being compressed while being bent.  Because the inner radius of the bend remains a constant length, the center wire core is forced to elongate. With the excess wire spooled up at the sensor base, we simply measure how much we collected, apply some math, and get a resulting angle! What’s more, the folks behind this trick also demonstrate that the length and angle relationship is linear with an R-square of 0.9969.

One of the best parts about this sensor is how reproducible it seems from from a modest collection of stock parts. Spring guide (aka: extension spring) is available from McMaster-Carr and DR Templeman, and that flexible core might be readily substituted with some wire rope.

It’s not everyday that new topologies for bend sensors pop into the world, let alone linear ones. To learn more, the folks behind the project have kindly made their research paper open access for your afternoon reading enjoyment. (Bring scratch paper!) Finally, if you’re looking for other bend-related sensors, have a look at this multi-bend measurement setup.

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Autonomous Multi-Task Performing Robot

September 14, 2020 by No comments

[Ruchir] has been pretty into robotics for a while now and has always been amused by the ever-popular obstacle avoiding robot, but wanted something that could do more. So, like any good hacker, he decided to build something himself.

He wanted to incorporate all the popular beginner robot capabilities into a single invention. His robot can follow a line, detect an obstacle, and retrieve an object without switching between modes. It can even follow another robot, which is pretty neat.

His robot has a lot of the hardware you would expect. It uses a Raspberry Pi for all the heavy image processing, has optical sensors for line following and obstacle avoidance, and includes a speaker for audio feedback. What’s especially cool is the impressive interface, called the Regbot GUI, that [Ruchir] is using with his robot. According to the Wiki page, the Regbot GUI appears to accompany an educational robotics platform developed by Professor Jens Christian Andersen of the Technical University of Denmark for teaching controls to engineering students. [Ruchir] was able to adapt the GUI to his particular bot no problem.

Using the Regbot GUI, [Ruchir] can monitor all the robot’s sensor data in real-time (accelerometer, gyroscope, distance sensor, servo, encoder, etc.), dynamically adjust its calibration settings if needed, or even provide a universal killswitch in case the unthinkable happens. We’d say it’s definitely worth a look before you embark on your next robotics project.

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Ultra-Mobile Little Robot Will Climb The Walls

September 7, 2020 by 6 Comments

Can it crawl? Can it climb? Can it roll? Can it skate? Can it draw? Naminukas by [Mykolas Juraitis] can do all of those things, and it is the size of a winter boot. Roving robots generally fall into one locomotion category, and the fanciest are amphibious. We categorize this one as transforming between three modes.

The first mode is like an inch-worm and a robot arm. Using a vacuum cup at the hub of each wheel, it sticks one end to the ground then heaves itself in the direction it wants to go and repeats. Its second form is a two-wheel balancing robot, which is the fastest configuration, and it can even carry things on its suckers. For the finale, it can hybridize all the tricks and use a camera dolly like a skateboard. One end sticks to the dolly, and the other is a propulsion wheel.

Naminukas is not just about scooting around the floor, because it can use tools with enough dexterity to write legibly on a whiteboard, climb walls, and even move around the ceiling. If these become sentient, there will be no place to hide, except a room with shag carpet, and is that any way to live?

We enjoy multi-terrain vehicles from soaring seaplanes to tidal tanks.

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ExoMy Is A Miniature European Mars Rover With A Friendly Face

September 5, 2020 by 5 Comments

Over the past few weeks, a new season of Mars fever kicked off with launches of three interplanetary missions. And since there’s a sizable overlap between fans of spaceflight and those of electronics and 3D printing, the European Space Agency released the ExoMy rover for those who want to experience a little bit of Mars from home.

ExoMy’s smiling face and cartoonish proportions are an adaptation of ESA’s Rosalind Franklin (formerly the ExoMars) rover which, if 2020 hadn’t turned out to be 2020, would have been on its way to Mars as well. While Rosalind Franklin must wait for the next Mars launch window, we can launch ExoMy missions to our homes now. Like the real ESA rover, ExoMy has a triple bogie suspension design distinctly different from the rocker-bogie design used by NASA JPL’s rover family. Steering all six wheels rather than just four, ExoMy has maneuvering chops visible in a short Instagram video clip (also embedded after the break).

ExoMy’s quoted price of admission is in the range of 250-500€. Perusing instructions posted on GitHub, we see an electronics nervous system built around a Raspberry Pi. Its published software stack is configured for human remote control, but as it is already running ROS (Robot Operating System), it should be an easy on-ramp for ExoMars builders with the ambition of adding autonomy.

ExoMy joins the ranks of open source rover designs available to hackers with 3D printing, electronics, and software skills. We recently covered a much larger rover project modeled after Curiosity. Two years ago NASA JPL released an open source rover of their own targeting educators, inspiring this writer’s own Sawppy rover project, which is in turn just one of many projects tagged “Rover” on Hackaday.io. Hackers love rovers!