Planet Arduino

Building a robot is only half the battle, because you also need a way to control it. Something like a rover may work with a simple joystick or even typed commands. But complex robots often have many motors and controlling those all directly becomes a challenge. That’s why Will Cogley chose motion control for his bionic hand.

This is the newest iteration of a project that Cogley first started a few years ago. It is robotic hand meant to mimic a human hand as much as possible. Human fingers do not contain muscles. Instead, muscles in the forearms and palms pull on tendons to move the fingers. Cogley’s bionic hand works in a similar manner by using servo motors in the forearm to pull on cables that actuate the fingers. An Arduino UNO Rev3 moves the servos according to commands from a PC, but Cogley needed a way to streamline those commands.

Cogley chose a Leap Motion Controller for this job. It can track the motion of the user’s hand in near real-time and update a 3D model on the computer to reflect that. It displays that model in Unity, which is a 3D game engine that has the flexibility to perform in applications like this. Unity can determine the angle of each joint and Cogley was able to take advantage of the Uduino plugin to send servo commands to the Arduino based on those angles.

The result is a bionic hand that moves to match the user’s own hand.

The post This bionic hand responds to motion control appeared first on Arduino Blog.

Ivan Miranda has a humble dream: he wants to build a massive 3D-printed robot that he can ride upon. In other words, he wants a mech. But that is obviously a very challenging project that will take an incredible amount of time and money. So he decided to test the waters with one piece of the mech: a huge 3D-printed robotic hand.

Miranda designed this robotic hand at the scale necessary for an enormous rideable mech, but he has only built the one hand at this point. This let him test the idea before jumping into the deep end with the full project. The structure and most of the mechanical components were 3D-printed. It has four fingers and a thumb, each with three joints (like a real human hand). It is mostly rigid PLA, but there are some flexible TPU parts that add grip.

Servos actuate all 15 of those joints. Most of them have 11kg-cm of torque, but the base of each finger has a more powerful servo with 25kg-cm of torque. An Arduino Mega 2560 controls all of the servo motors with pulse-width modulation (PWM) signals. Power, of course, comes directly from the power supply and not the Arduino.

In testing, the hand seems to work quite well. It can move and grip large objects, though the belts do slip and need to be replaced with a type that can’t stretch. We’re not sure if Miranda will complete the entire mech, but we sure hope that he does!

The post This gargantuan 3D-printed robot hand is just the beginning appeared first on Arduino Blog.

[Miller] wanted to practice a bit with some wireless modules and wound up creating a robotic hand he could teleoperate with the help of a haptic glove. It lookes highly reproducible, as you can see the video, below the break.

The glove uses an Arduino’s analog to digital converter to read some flex sensors. Commercial flex sensors are pretty expensive, so he experimented with some homemade sensors. The ones with tin foil and graphite didn’t work well, but using some bent can metal worked better despite not having good resolution.

The wireless communications set up was pretty easy thanks to the NRF24L01 modules. The hard part was sewing the flex sensors into the glove. We thought some of the circuitry looked precarious on the glove, too.

For the robot hand, he used balsa wood and hinges for each joint. Flexible thread provided the return power like a spring. The hand was surprisingly artistic in a primitive sort of way.

While this is a cool demo, the hand isn’t likely to be practical for much as it is. Nerve impulses are better but harder. The glove reminded us a little of one we’d seen before.

Gray Eldritch (AKA The Technomanc3r) has been working on a robotic hand for some time now, and has settled (so far) on a design with three independent servo-actuated fingers and a thumb. He’s also implemented a wrist assembly to rotate it back and forth, with an Arduino Uno hidden inside for an entirely self-contained gripper unit.

Each of the three fingers is controlled by a single MG996R servo, as is the wrist, while the thumb adds a second SG90 servo to allow it to move on two axes. The fingers are modular, so they can be swapped out as needed, and you even change the thumb position for ambidextrous operation. 

It remains to be seen what Eldritch plans to do with the gripper, but it looks brilliant by itself in the video below.

With the lack of people capable of turning written or spoken words into sign language in Belgium, University of Antwerp masters students Guy Fierens, Stijn Huys, and Jasper Slaets have decided to do something about it. They built a robot known as Aslan, or Antwerp’s Sign Language Actuating Node, that can translate text into finger-spelled letters and numbers.

Project Aslan–now in the form of a single robotic arm and hand–is made from 25 3D-printed parts and uses an Arduino Due, 16 servos, and three motor controllers. Because of its 3D-printed nature and the availability of other components used, the low-cost design will be able to be produced locally.

The robot works by receiving information from a local network, and checking for updated sign languages from all over the world. Users connected to the network can send messages, which then activate the hand, elbow, and finger joints to process the messages.

Although it is one arm now, work will continue with future masters students, focusing on expanding to a two-arm design, implementing a face, and even integrating a webcam into the system. For more info, you can visit the project’s website here as well as its write-up on 3D Hubs.

How do you make a robot hand? If you are [Robimek], you start with some plastic spiral tubing, some servo motors, and some fishing line. Oh, and you also need an old glove.

The spiral tubing (or pipe, if you prefer) is cut in a hand-like shape and fused together with adhesive. The knuckle joints are cut out to allow the tubing to flex at that point. The fishing line connects the fingertips to the servo motors.

The project uses an Arduino to drive the servos, although you could do the job with any microcontroller. Winding up the fishing line contracts the associated finger. Reeling it out lets the springy plastic pipe pull back to its original position.The glove covers the pipes and adds a realistic look to the hand.

Granted, this is probably more practical as a display piece than a working hand. We’d like to put it in our next Halloween project. We’ve seen some simple hand builds before, but the glove is a nice touch. For some reason, many of our robot hand projects like to make rude gestures. You can see a video of [Robimek]’s hand working below.