Posts with «robots hacks» label

3D Printed Gesture-Controlled Robot Arm is a Ton of Tutorials

Ever wanted your own gesture-controlled robot arm? [EbenKouao]’s DIY Arduino Robot Arm project covers all the bases involved, but even if a robot arm isn’t your jam, his project has plenty to learn from. Every part is carefully explained, complete with source code and a list of required hardware. This approach to documenting a project is great because it not only makes it easy to replicate the results, but it makes it simple to remix, modify, and reuse separate pieces as a reference for other work.

[EbenKouao] uses a 3D-printable robotic gripper, base, and arm design as the foundation of his build. Hobby servos and a single NEMA 17 stepper take care of the moving, and the wiring and motor driving is all carefully explained. Gesture control is done by wearing an articulated glove upon which is mounted flex sensors and MPU6050 accelerometers. These sensors detect the wearer’s movements and turn them into motion commands, which in turn get sent wirelessly from the glove to the robotic arm with HC-05 Bluetooth modules. We really dig [EbenKouao]’s idea of mounting the glove sensors to this slick 3D-printed articulated gauntlet frame, but using a regular glove would work, too. The latest version of the Arduino code can be found on the project’s GitHub repository.

Most of the parts can be 3D printed, how every part works together is carefully explained, and all of the hardware is easily sourced online, making this a very accessible project. Check out the full tutorial video and demonstration, embedded below.

3D printing has been a boon for many projects, especially those involving robotic arms. All kinds of robotic arm projects benefit from the advantages of 3D printing, from designs that focus on utility and function, to clever mechanical designs that reduce part count in unexpected ways.

Nightmare Robot Only Moves When You Look Away

What could be more terrifying than ghosts, goblins, or clowns? How about a shapeless pile of fright on your bedroom floor that only moves when you’re not looking at it? That’s the idea behind [Sciencish]’s nightmare robot, which is lurking after the break. The Minecraft spider outfit is just a Halloween costume.

In this case, “looking at it” equates to you shining a flashlight on it, trying to figure out what’s under the pile of clothes. But here’s the thing — it never moves when light is shining on it. It quickly figures out the direction of the light source and lies in wait. After you give up and turn out the flashlight, it spins around to where the light was and starts moving in that direction.

The brains of this operation is an Arduino Uno, four light-dependent resistors, and a little bit of trigonometry to find the direction of the light source. The robot itself uses two steppers and printed herringbone gears for locomotion. Its chassis has holes in it that accept filament or wire to make a cage that serves two purposes — it makes the robot into more of an amorphous blob under the clothes, and it helps keep clothes from getting twisted up in the wheels. Check out the demo and build video after the break, because this thing is freaky fast and completely creepy.

While we usually see a candy-dispensing machine or two every Halloween, this year has been more about remote delivery systems. Don’t just leave sandwich bags full of fun size candy bars all over your porch, build a candy cannon or a spooky slide instead.

Via r/duino

3D Printed SCARA Arm With 3D Printer Components

One of the side effects of the rise of 3D printers has been the increased availability and low cost of 3D printer components, which are use fill for range of applications. [How To Mechatronics] capitalized on this and built a SCARA robot arm using 3D-printed parts and common 3D-printer components.

The basic SCARA mechanism is a two-link arm, similar to a human arm. The end of the second joint can move through the XY-plane by rotating at the base and elbow of the mechanism. [How To Mechatronics] added Z-motion by moving the base of the first arm on four vertical linear rods with a lead screw. A combination of thrust bearings and ball bearings allow for smooth rotation of each of the joints, which are belt-driven with NEMA17 stepper motors. Each joint has a microswitch at a certain position in its rotation to give it a home position. The jaws of the gripper slide on two parallel linear rods, and are actuated with a servo. For controlling the motors, an Arduino Uno and CNC stepper shield was used.

The arm is operated from a computer with a GUI written in Processing, which sends instructions to the Arduino over serial. The GUI allows for both direct forward kinematic control of the joints, and inverse kinematic control,  which will automatically move the gripper to a specified coordinate. The GUI can also save positions, and then string them together to do complete tasks autonomously.

The base joint is a bit wobbly due to the weight of the rest of the arm, but this could be fixed by using a frame to support it at the top as well. We really like the fact that commonly available components were used, and the link in the first paragraph has detailed instructions and source files for building your own. If the remaining backlash can be solved, it could be a decent light duty CNC platform, especially with the small footprint and large travel area. This is very similar to a wooden SCARA robots we’ve seen before, except that one put the Z-axis at the gripper. We’ve also seen a few 3D printers and pen plotters that used this layout.

Lego Ziplining Robot Climbs for Claps

The internet has given us plenty of cool robotics projects, but we don’t think we’ve seen one zipline before. At least not until now.

This cool little ziplining robot is courtesy of the folks over at [Tart Robotics]. As they described it, the robot moves using a 4-bar linkage mechanism with the motor’s torque “transferred to the arm mechanisms through a pair of bevel gears and a worm drive.” Even cooler, the robot is activated by clapping. The faster you clap, the faster the robot moves. That’s sure to wow your friends at your next virtual hacker meetup.

They had to do a bit of custom 3D printing work to get a few of the Lego components to connect with their non-Lego off-the-shelf bits, so that took a bit of time. Specifically, they had some cheap, non-branded DC motors that they used that did not naturally mate with the Lego Technic components used to create the rest of the robot’s body. Nothing a few custom 3D printing jobs couldn’t solve.

It always amazes us what cool contraptions you can put together with a few Lego blocks. What’s your favorite Lego project?

Open-Source Robotic Arm for All Purposes

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.

Miles the Spider Robot

Who doesn’t love robotic spiders? Today’s biomimetic robot comes in the form of Miles, the quadruped spider robot from [_Robox].

Miles uses twelve servos to control its motion, three on each of its legs, and also includes a standard HC-SR04 ultrasonic distance sensor for some obstacle avoidance capabilities. Twelve servos can use quite a bit of power, so [_Robox_] had to power Miles with six LM7805 ICs to get sufficient current. [_Robox_] laser cut acrylic sheets for Miles’s body but mentions that 3D printing would work as well.

Miles uses inverse kinematics to get around, which we’ve seen in a previous project and is a pretty popular technique for controlling robotic motion. The Instructable is a little light on the details, but the source code is something to take a look at. In addition to simply moving around [_Robox_] developed code to make Miles dance, wave, and take a bow. That’s sure to be a hit at your next virtual show-and-tell.

By now you’re saying “wait, spiders have eight legs”, and of course you’re right. But that’s an awful lot of servos. Anyway, if you’d rather 3D print your four-legged spider, we have a suggestion.

Robotic Cornhole Board Does the Electric Slide

There’s a reason why bowling lanes have bumpers and golf games have mulligans. Whether you’re learning a new game or sport, or have known for years how to play but still stink at it, everyone can use some help chasing that win. You’ve heard of the can’t-miss dart board and no-brick basketball goal. Well, here comes the robot-assisted game for the rest of us: cornhole.

The game itself deceptively simple-looking — just underhand throw a square wrist rest into a hole near the top of a slightly angled box. You even get a point for landing anywhere on the box! Three points if you make it in the cornhole. In practice, the game not that easy, though, especially if you’ve been drinking (and drinking is encouraged). But hey, it’s safer than horseshoes or lawn darts.

[Michael Rechtin] loves the game but isn’t all that great at it, so he built a robotic version that tracks the incoming bag and moves the hole to help catch it. A web cam mounted just behind the hole takes a ton of pictures and analyzes the frames for changes.

The web cam sends the bag positions it sees along with its predictions to an Arduino, which decides how it will move a pair of motors in response. Down in the cornhole there’s a pair of drawer sliders that act as the lid’s x/y gantry.

We love how low-tech this is compared to some of the other ways it could be done, even though it occasionally messes up. That’s okay — it makes the game more interesting that way. We think you should get 2 points if it lands halfway in the hole. Aim past the break to check out the build video.

Seems like there’s a robotic-assisted piece of sporting equipment for everything these days. If cornhole ain’t your thing, how’d you like to take a couple strokes off your golf game?

Thanks for the tip, [Itay]!

DIY Baby MIT Cheetah Robot

3D printers have become a staple in most makerspaces these days, enabling hackers to rapidly produce simple mechanical prototypes without the need for a dedicated machine shop. We’ve seen many creative 3D designs here on Hackaday and [jegatheesan.soundarapandian’s] Baby MIT Cheetah Robot is no exception. You’ve undoubtedly seen MIT’s cheetah robot. Well, [jegatheesan’s] hack takes a personal spin on the cheetah robot and his results are pretty cool.

The body of the robot is 3D printed making it easy to customize the design and replace broken parts as you go. The legs are designed in a five-bar linkage with two servo motors controlling each of the four legs. An additional servo motor is used to rotate an HC-SR04, a popular ultrasonic distance sensor, used in the autonomous mode’s obstacle avoidance mechanism. The robot can also be controlled over Bluetooth using an app [jegatheesan] developed in MIT App Inventor.

Overall, the mechanics could use a bit of work — [jegatheesan’s] baby cheetah probably won’t outpace MIT’s robot any time soon — but it’s a cool hack and we’re looking forward to a version 3. Maybe the cheetah would make a cool companion bot?

Robotic Biped Walks On Inverse Kinematics

Robotics projects are always a favorite for hackers. Being able to almost literally bring your project to life evokes a special kind of joy that really drives our wildest imaginations. We imagine this is one of the inspirations for the boom in interactive technologies that are flooding the market these days. Well, [Technovation] had the same thought and decided to build a fully articulated robotic biped.

Each leg has pivot points at the foot, knee, and hip, mimicking the articulation of the human leg. To control the robot’s movements, [Technovation] uses inverse kinematics, a method of calculating join movements rather than explicitly programming them. The user inputs the end coordinates of each foot, as opposed to each individual joint angle, and a special function outputs the joint angles necessary to reach each end coordinate. This part of the software is well commented and worth your time to dig into.

In case you want to change the height of the robot or its stride length, [Technovation] provides a few global constants in the firmware that will automatically adjust the calculations to fit the new robot’s dimensions. Of all the various aspects of this project, the detailed write-up impressed us the most. The robot was designed in Fusion 360 and the parts were 3D printed allowing for maximum design flexibility for the next hacker.

Maybe [Technovation’s] biped will help resurrect the social robot craze. Until then, happy hacking.

Switch Tester Servo-Slaps Them ’til they Fail

[James] is designing an open-source 3D printed keyboard switch, with the end goal of building a keyboard with as many printed parts as possible. Since keyswitches are meant to be pressed quite often, the DIY switches ought to be tested just as rigorously as their commercial counterparts are at the factory. Maybe even more so.

The broken spring after 13,000+ automated boings.

Rather than wear out his fingers with millions of actuations, [James] built a robot to test switches until they fail. All he has to do is plug a switch in, and the servo-driven finger slowly presses the slider down until the contacts close, which lights the LED.

The system waits 100ms for the contacts to stop any tiny vibrations before releasing the slider. That Arduino on the side tracks the contact and release points and sends them to the PC to be graphed. If the switch fails to actuate or release, the tester stops altogether.

We love that this auto-tester works just fine for commercial switches, too — the bit that holds the switch is separate and attaches with screws, so you could have one for every footprint variant. [James] recently did his first test of a printed switch and it survived an astonishing 13,907 presses before the printed coil spring snapped.

One could argue that this doubles as a servo tester. If you want a dedicated device for that, this one can test up to sixteen at a time.

Via @Microchip_Makes