Robots Hacks

2346 Articles

Robotic Worm Uses NinjaFlex Filament

September 24, 2020 by 8 Comments

If you think about building a moving machine, you probably will consider wheels or tracks or maybe even a prop to take you airborne. When [nwlauer] found an earthworm in the garden, it inspired a 3D-printed robot that employs peristaltic motion. You can see a video of it moving, below.

The robot uses pneumatics and soft plastic, and is apparently waterproof. Your printer’s feed path has to be pretty rigid to support flexible filament without jamming. There’s also some PVA filament and silicone tubing involved.

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Roller-Based Robot Hand Grasps

September 24, 2020 by 3 Comments

In a recent International Conference on Robotics and Automation paper, [Shenli Yaun] and some others from Stanford discuss the design of a roller-based robot hand that has many features that mimic the human hand. The key feature is that each of the three fingers has a roller with a small geared motor.

The rollers allowed the hand to change an object’s orientation without losing its grasp. Of course, this works well with spherical objects like a ball. But the video shows that it can manipulate other items like a 6-sided die, a water bottle, or even a piece of paper. By spreading the fingers it can even hold large objects you wouldn’t expect at first glance.

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Linkage Inferring Software Handwaves Away The Hard Stuff

September 22, 2020 by 17 Comments

Jokes aside, manually designing linkages that move along specific paths is no easy task. Whether we’re doodling paper sketches or constraining lines in a CAD program, we still need to do the work of actually “imagining” the linkage design. If only there were some sort of tool that would do all that hard imagining work for us! Thankfully, we’re in luck! That’s exactly what researchers [Gen Nishida], [Adrien Bousseau2], and [Daniel G. Aliaga1] at Purdue have done. They’ve designed a software tool that lets us position important bodies in space in particular “key” frames, and then the software simply fills in the linkage for you!

To start the design process, the user inputs a few candidate locations that their solid bodies need to reach in the final linkage path.  From here, these locations get fed to a particle filter. This particle filter seeds thousands of semi-random linkage configurations at small timesteps, selects some of the best-matching ones that most closely approximate the required body locations, removes the lesser-scoring results, re-creates a new set of possible joint configurations based on the best matching ones, and repeats until the tool converges on a linkage that respects our input key frames.

Like a brute force search, this solution takes lots and lots of samples to find a solution, but unlike a brute force search, trials iteratively improve, enabling the software to converge closer and closer to a final solution. Under the hood, the software needs to actually simulate these candidate linkage in order to grade them. It’s in this step that the team wrote in additional checks to remove impossible linkages like self-intersecting joints from this linkage “gene pool” before reseeding them. The result is a tool that does all that trial-and-error scratchwork for you–no brain cycles. For more details, have a peek at their (open access!) paper.

Design software that augments our mechanical design capabilities is a rare gem on these pages, and this one is no exception. If your curious to play with other useful linkages simulating tools, have a go at Linkage Designer. And if you’re in the mood for other tools that fill in the blanks, check out this machine learning algorithm that literally fills in footage between frames in a video feed.

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Autonomous Rover Navigates The House With LIDAR

September 22, 2020 by 1 Comment

For those wishing to explore robot autonomy, there’s no better way then to learn by doing. [Greg] was in that camp, and decided to build an autonomous rover to roam his house, and learned plenty along the way.

[Greg]’s aims with the project were to build a robot that was capable of navigating his home without external assistance. To do the job, a Raspberry Pi 3 was put in charge, and kitted out with a LIDAR for mapping. Pololu Roboclaw motor controllers are then used to allow the Raspberry Pi to drive the robot’s individual wheel motors, giving the four-wheeled bot skid steering capability.

[Greg] goes into immense detail on the project’s writeup, exploring the code and concepts behind its autonomous abilities. Creating a robot that can navigate using LIDAR is no easy task, but [Greg] does a great job of explaining how it all works, and why.

It’s not the first autonomous rover we’ve seen here, and we’re sure it won’t be the last. If you’ve got your own build coming together in the lab, be sure to let us know. Video after the break.

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TOBOT Is Your Tic Tac Toe Opponent With A Bad Attitude

September 16, 2020 by 4 Comments

[3dprintedlife] is apparently a little bored. Instead of whiling away the time playing tic tac toe, he built an impressive tic tac toe robot named TOBOT. The robot uses a Rasberry Pi Zero and a Feather to control a two-axis robot arm that can draw the board and make moves using a pen. It also uses a simple computer vision system to look at the board to understand your move, and it has a voice too.

The other thing TOBOT has is a bad attitude. The robot wants to win. Badly. Check out the video below and you’ll see what we mean.

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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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