Salamander Robot Is Squishy

April 8, 2025 by Al Williams 7 Comments

If you want to get started in microfluidic robotics, [soiboi soft’s] salamander is probably too complex for a first project. But it is impressive, and we bet you’ll learn something about making this kind of robot in the video below.

The pneumatic muscles are very impressive. They have eight possible positions using three sources of pressure. This seems like one of those things that would have been nearly impossible to fabricate in a home lab a few decades ago and now seems almost trivial. Well, maybe trivial isn’t the right word, but you know what we mean.

The soft robots use layers of microfluidic channels that can be made with a 3D printer. Watching these squishy muscles move in an organic way is fascinating. For right now, the little salamander-like ‘bot has a leash of tubes, but [soiboi] plans to make a self-contained version at some point.

If you want something modular, we’ve seen Lego-like microfluidic blocks. Or, grab the shrinky dinks.

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Printed Robotic Arm Pumps Up With Brushless Motors

April 8, 2025 by Tom Nardi 17 Comments

[JesseDarr] recently wrote in to tell us about their dynamic Arm for Robitc Mischief (dARM), a mostly 3D printed six degrees of freedom (6DOF) robotic arm that’s designed to be stronger and more capable than what we’ve seen so far from the DIY community.

The secret? Rather than using servos, dARM uses brushless DC (BLDC) motors paired with ODrive S1 controllers. He credits [James Bruton] and [Skyentific] (two names which regular Hackaday readers are likely familiar with) for introducing him to not only the ODrive controllers, but the robotics applications for BLDCs in the first place.

dARM uses eight ODrive controllers on a CAN bus, which ultimately connect up to a Raspberry Pi 4B with a RS485 CAN Hat. The controllers are connected to each other in a daisy chain using basic twisted pair wire, which simplifies the construction and maintenance of the modular arm.

As for the motors themselves, the arm uses three different types depending on where they are located, with three Eaglepower 8308 units for primary actuators, a pair of GB36-2 motors in the forearm, and finally a GM5208-24 for the gripper. Together, [JesseDarr] says the motors and gearboxes are strong enough to lift a 5 pound (2.2 kilogram) payload when extended in a horizontal position.

The project’s documentation includes assembly instructions for the printed parts, a complete Bill of Materials, and guidance on how to get the software environment setup on the Raspberry Pi. It’s not exactly a step-by-step manual, but it looks like there’s more than enough information here for anyone who’s serious about building a dARM for themselves.

If you’d like to start off by putting together something a bit easier, we’ve seen considerably less intimidating robotic arms that you might be interested in.

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Disney’s Bipedal, BDX-Series Droid Gets The DIY Treatment

April 5, 2025 by Donald Papp 5 Comments

[Antoine Pirrone] and [Grégoire Passault] are making a DIY miniature re-imagining of Disney’s BDX droid design, and while it’s still early, there is definitely a lot of progress to see. Known as the Open Duck Mini v2 and coming in at a little over 40 cm tall, the project is expected to have a total cost of around 400 USD.

The inner workings of Open Duck Mini use a Raspberry Pi Zero 2W, hobby servos, and an absolute-orientation IMU.

Bipedal robots are uncommon, and back in the day they were downright rare. One reason is that the state of controlled falling that makes up a walking gait isn’t exactly a plug-and-play feature.

Walking robots are much more common now, but gait control for legged robots is still a big design hurdle. This goes double for bipeds. That brings us to one of the interesting things about the Open Duck Mini v2: computer simulation of the design is playing a big role in bringing the project into reality.

It’s a work in progress but the repository collects all the design details and resources you could want, including CAD files, code, current bill of materials, and links to a Discord community. Hardware-wise, the main work is being done with very accessible parts: Raspberry Pi Zero 2W, fairly ordinary hobby servos, and an BNO055-based absolute orientation IMU.

So, how far along is the project? Open Duck Mini v2 is already waddling nicely and can remain impressively stable when shoved! (A “testing purposes” shove, anyway. Not a “kid being kinda mean to your robot” shove.)

Check out the videos to see it in action, and if you end up making your own, we want to hear about it, so remember to send us a tip!

Simple Robot Assembled From E-Waste Actually Looks Pretty Cool

March 17, 2025 by Lewin Day 9 Comments

If you’re designing a robot for a specific purpose, you’re probably ordering fresh parts and going with a clean sheet design. If you’re just building for fun though, you can just go with whatever parts you have on hand. That’s how [Sorush Moradisani] approached building Esghati—a “robot made from garbage.”

The body of the robot is an old Wi-Fi router that was stripped clean, with the antenna left on for a classic “robot” look. The wheels are made out of old diffusers cut off of LED lamps. Two servos are used to drive the wheels independently, allowing the robot to be steered in a rudimentary tank-style fashion. Power is courtesy of a pair of 18650 lithium-ion cells. The brains of the robot is an ESP32-CAM—a microcontroller board which includes a built-in camera. Thanks to its onboard Wi-Fi, it’s able to host its own website that allows control of the robot and transmits back pictures from the camera. The ESP32 cam itself is mounted on the “head” on the robot for a good field of view. Meanwhile, it communicates with a separate Arduino Nano which is charged with generating pulses to run the drive servos. Code is on Github for the curious.

It’s not a complicated robot by any means—it’s pretty much just something you can drive around and look through the camera, at this stage. Still, it’s got plenty of onboard processing power and you could do a lot more with it. Plus, the wireless control opens up a lot of options. With that said, you’d probably get sick of the LED bulb wheels in short order—they offer precious little grip on just about any surface. Really, though, it just goes to show you how a bit of junk e-waste can make a cute robot—it almost has Wall-E vibes. Video after the break.

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Pi Hand Is A Digital Display Of A Different Sort

March 14, 2025 by Tom Nardi 8 Comments

Hackers enjoy a good theme, and so it comes as no surprise that every time March 14th (Pi Day) rolls around, the tip line sees an uptick in mathematical activity. Whether it’s something they personally did or some other person’s project they want to bring to our attention, a lot of folks out there are very excited about numbers today.

One of our most prolific circumference aficionados is [Cristiano Monteiro], who, for the last several years, has put together a special project to commemorate the date. For 2025, he’s come up with a robotic hand that will use its fingers to show the digits of Pi one at a time. Since there’s only one hand, anything higher than five will be displayed as two gestures in quick succession, necessitating a bit of addition on the viewer’s part.

[Cristiano] makes no claims about the anatomical accuracy of his creation. Indeed, if your mitts look anything like this, you should seek medical attention immediately. But whether you think of them as fingers or nightmarish claws, it’s the motion of the individual digits that matter.

To that end, each one is attached to an MG90 servo, which an Arduino Nano drives with attached Servo Shield. From there, it’s just a matter of code to get the digits wiggling out the correct value, which [Cristiano] has kindly shared for anyone looking to recreate this project.

If you’re hungry for more Pi, the ghostly display that [Cristiano] sent in last year is definitely worth another look. While not directly related to today’s mathematical festivities, the portable GPS time server he put together back in 2021 is another fantastic build you should check out.

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Taming The Wobble: An Arduino Self-Balancing Bot

March 9, 2025 by Heidi Ulrich 12 Comments

Getting a robot to stand on two wheels without tipping over involves a challenging dance with the laws of physics. Self-balancing robots are a great way to get into control systems, sensor fusion, and embedded programming. This build by [mircemk] shows how to make one with just a few common components, an Arduino, and a bit of patience fine-tuning the PID controller.

At the heart of the bot is the MPU6050 – a combo accelerometer/gyroscope sensor that keeps track of tilt and movement. An Arduino Uno takes this data, runs it through a PID loop, and commands an L298N motor driver to adjust the speed and direction of two DC motors. The power comes from two Li-ion batteries feeding everything with enough juice to keep it upright. The rest of the magic lies in the tuning.

PID (Proportional-Integral-Derivative) control is what makes the robot stay balanced. Kp (proportional gain) determines how aggressively the motors respond to tilting. Kd (derivative gain) dampens oscillations, and Ki (integral gain) helps correct slow drifts. Set them wrong, and your bot either wobbles like a confused penguin or falls flat on its face. A good trick is to start with only Kp, then slowly add Kd and Ki until it stabilizes. Then don’t forget to calibrate your MPU6050; each sensor has unique offsets that need to be compensated in the code.

Once dialed in, the result is a robot that looks like it defies gravity. Whether you’re hacking it for fun, turning it into a segway-like ride, or using it as a learning tool, a balancing bot is a great way to sharpen your control system skills. For more inspiration, check out this earlier attempt from 2022, or these self-balancing robots (one with a little work) from a year before that. You can read up on [mircemk]’s project details here.

A Transparent BB-8 Build Using Christmas Ornaments

February 13, 2025 by Lewin Day 10 Comments

The cool thing about the droids of Star Wars is that they’re not that hard to recreate in real life. R2-D2 is a popular choice, but you can even build yourself a neat little BB-8 if you’re so inclined. [Piyush] has built a particularly compelling example that’s transparent, which lets you see the internals and how it all works.

The build makes creative use of a pair of Christmas ornaments. They are perhaps the cheapest and easiest way to source a clear plastic sphere. One serves as the “head”, while the other serves as the larger spherical body. Inside, an Arduino Pro Micro is running the show. It’s hooked up to a L293D motor driver which runs the drive motors and the reaction wheel motor which provides stability, while a separate MOSFET is on hand to run the gear motor which controls the head.

There’s also an HC-05 module for Bluetooth communication, and a BNO055 sensor for motion tracking and ensuring the robot stays the right way up. 3D printed components are used prodigiously to cram everything together tightly enough to fit. There’s even a printed charging base to juice up the little droid. Controlling the robot is as simple as using a smartphone with an app created in the MIT App Inventor.

If you’ve never built a spherical rolling robot before—and few of us have—this design is a great reference for your own work. We’ve seen a few BB-8s over the years, most of which dropped shortly after the movie was released. Continue reading “A Transparent BB-8 Build Using Christmas Ornaments” →