[madcowswe] starts by pointing out that the entire premise of ODrive (an open-source brushless motor driver board) is to make use of inexpensive brushless motors in industrial-type applications. This usually means using hobby electric aircraft motors, but robotic applications sometimes need more torque than those motors can provide. Adding a gearbox is one option, but there is another: so-called “hoverboard” motors are common and offer a frankly outstanding torque-to-price ratio.
A teardown showed that the necessary mechanical and electrical interfacing look to be worth a try, so prototyping has begun. These motors are really designed for spinning a tire on the ground instead of driving other loads, but [madcowswe] believes that by adding an encoder and the right fixtures, these motors could form the basis of an excellent robot arm. The ODrive project was a contender for the 2016 Hackaday Prize and we can’t wait to see where this ends up.
[Tobias Kuhn] had watched a YouTube video about a robot arm which used servo motors, and wanted to try making one himself. But he found it hard to get slow or smooth movements out of the servos. Even removing the microcontroller and trying to work with the servo’s driver-IC and potentiometer from an Arduino Nano didn’t get him satisfaction.
Then he found the very affordable 28BYJ-48 stepper motor. After some experimenting, he came up with a smooth moving robot arm with four steppers controlled from an Arduino Mega and A4988 stepper motor drivers. Rather than write a bunch of stepper motor code himself, he installed and ran a four-axis fork of grbl on the Arduino, turning it into a stepper motor controller. One minor hitch was that the A4988 motor drivers are for bipolar stepper motors but 28BYJ-48 steppers are unipolar. Luckily he knew of a very simple hack which our [Brian Benchoff] wrote about for turning a unipolar motor into a bipolar motor.
To tell the robot arm what to do, he built a replica arm with potentiometers in place of the stepper motors. As he manipulates the replica, the values of the potentiometers are read by a Raspberry Pi and some custom Python code which sends the appropriate G-code to the Arduino/grbl controlled robot arm. There’s a bit of a lag but when he moves the replica arm, the robot arm does the same move. See it in action in the video below.
Continue reading “Stepper Motor Robot Arm Has Smooth Moves”
We’ve seen industrial robotic arms in real life. We’ve seen them in classrooms and factories. Before today, we’ve never mistaken a homemade robotic arm for one of the price-of-a-new-home robotic arms. Today, [Chris Annin] made us look twice when we watched the video of his six-axis robotic arm. Most of the DIY arms have a personal flare from their creator so we have to assume [Chris Annin] is either a robot himself or he intended to build a very clean-looking arm when he started.
He puts it through its paces in the video, available after the break, by starting with some stretches, weight-lifting, then following it up and a game of Jenga. After a hard day, we see the arm helping in the kitchen and even cracking open a cold one. At the ten-minute mark, [Chris Annin] walks us through the major components and talks about where to find many, many more details about the arm.
Many of the robotic arms on Hackaday are here by virtue of resourcefulness, creativity or unusual implementation but this one is here because of its similarity to the big boys.
Continue reading “Robotic Arm Rivals Industrial Counterparts”
MIT’s Computer Science and Artificial Intelligence Lab, CSAIL, has created a process of teleoperating a Baxter humanoid robot with an Oculus Rift VR headset. This project is partially aimed towards making manufacturing jobs
a hell of a lot of fun telecommutable. It could even be a way to supervise robot workers from a distance.
In a nutshell, the user controls the robot remotely in a virtual reality environment. The user does this specifically in a VR environment modeled like a control room with multiple sensor displays, making it feel like they are sitting inside the robot’s head. By using hand controllers, users can match their movements to the robot’s to complete various tasks. If you’ve seen Pacific Rim, you are probably envisioning a Jaegar right about now — minus the psychic linking.
Continue reading “Soon You’ll Sit Inside a Robot’s Head at Work”
If you deal with electronics, you probably think of static electricity as a bad thing. It blows up MOSFETs and ICs and we take a lot of pains to prevent that kind of damage. But a start-up company called Grabit is using static electricity as a way to allow robots to manipulate the real world. In particular, Nike is using these robots to build shoes. You can see a demo video, below.
Traditional robots use human-like hands or claw-like grippers to mimic how humans handle material. But Grabit has multiple patents on electroadhesion. The original focus was wall-climbing robots, but the real pay off has been in manufacturing robots since the electrostatic robots can do things that mechanical hands are a long way from duplicating.
Continue reading “The (Robot) Body Electric”
If you were a child of the 1980s whose fascination extended to the contents of your local Radio Shack store, you may remember the Armatron robot arm as a particular object of desire. It was a table top robot arm operated not by motors or a microcontroller, but by a clever set of gears directed manually from a pair of joysticks. If you took a look at it with an eye to control from your 8-bit home computer you were likely to be disappointed, but nevertheless it was an excellent toy.
The Armatron may be long gone, but if you hanker for a similar device you should take a look at [3D Meister]’s finger controlled six axis arm. This is an arm similar to the Armatron in size, but with far more capabilities. Control is via cable loops to sliders at the arm’s base, and in addition to the usual arm movements there is an extra loop which can be used to operate any of a selection of tools including a gripper, a magnet, and a clipper. The video below the break shows the arm in action, and for the faint-hearted it should be noted that it contains the gratuitous death of some innocent plants.
Continue reading “Hackaday Prize Entry: A Six Axis Robotic Arm With Fingertip Control”
When you’re running a Kickstarter for a robotic arm, you had better be ready to prove how repeatable and accurate it is. [Andrew] has done just that by laser engraving 400 wooden coasters with Evezor, his SCARA arm that runs on a Raspberry Pi computer with stepper control handled by a Smoothieboard.
Evezor is quite an amazing project: a general purpose arm which can do everything from routing circuit boards to welding given the right end-effectors. If this sounds familiar, that’s because [Andrew] gave a talk about Evezor at Hackaday’s Unconference in Chicago,
One of the rewards for the Evezor Kickstarter is a simple wooden coaster. [Anderw] cut each of the wooden squares out using a table saw. He then made stacks and set to programming Evezor. The 400 coasters were each picked up and dropped into a fixture. Evezor then used a small diode laser to engrave its own logo along with an individual number. The engraved coasters were then stacked in a neat output pile.
After the programming and setup were complete, [Andrew] hit go and left the building. He did keep an eye on Evezor though. A baby monitor captured the action in low resolution. Two DSLR cameras also snapped photos of each coaster being engraved. The resulting time-lapse video can be found after the break.
Continue reading “Evezor Robotic Arm Engraves 400 Coasters”