[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.
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”
3D printers were never meant to be used for production. They’re not manufacturing machines, they’re prototyping machines. That doesn’t mean 3D printers can’t be used in a manufacturing context, it’s just very hard – you’d need someone manning a fleet of machines, or some sort of ‘automated build platform’ that won’t be invented for exactly fourteen years.
In the absence of someone paid to watch printers print, [Mark], [Robert], and [James] at tend.ai have created a way to manage a fleet of printers with a robot arm. It’s a robotic arm that automatically monitors the LCD on a rack full of 3D printers, plucks the finished prints off the bed, drops the parts in a box, and starts another print.
Tend.ai is in the business of cloud robotics, and have designed a system that takes any robotic arm, any webcam, and provides the backend for this robotic arm to – wait for it – tend to other machines. As a demo, it works well. Parts are picked up off of the machines, dropped into boxes, and another print run started.
As a tech demo for a cloud robotics platform, you can’t do much better than this. As a way to automate a fleet of 3D printers, I can only wonder how this robot arm system would work with large, flat printed parts. A robotic gripper could always be replaced with a spatula, I guess.
You can check out the demo and the ‘how they did it’ video below.
Continue reading “Automating 3D Printers With Robots”
Robot arms are cool, and to judge from the SCARA arms and old Heathkit robots tucked away in a cupboard of every computer science department in every university in the world, they’re still remarkably educational. You can learn a lot about control systems with a robot arm, or you could build a clone of the old Radio Shack Armatron; either way, you’re doing something very cool. Right now, there aren’t many educational robot arms available, and the ones you can get are tiny. For [Jonathan]’s Hackaday Prize project, he’s building a low-cost robot arm with a one meter reach.
There’s a reason you won’t find many large, low-cost robot arms: the square cube law. An ant can carry many times its own body weight, but if you scaled that ant up to the size of a human, its legs couldn’t support itself. Likewise, a small, handheld robot arm will work perfectly well with hobby servos, but scaling this up requires big heavy stepper motors.
Continue reading “Hackaday Prize Entry: A Low-Cost Robot Arm”
Industrial robot arms are curious devices, found everywhere from the back of old engineering classrooms where they taught kinematics in the 90s, to the factory floor where they do the same thing over and over again while contemplating their existence. For his Hackaday Prize entry, [Dan] is building a big robot arm. It’s not big enough to ride on, but it is large enough to automate a few processes in a reasonably well-equipped lab.
This is not a tiny robotic arm powered by 9 gram hobby servos. For the bicep and tricep of [Dan]’s arm, he’s using linear actuators – they’re high precision and powerful. A few months ago, [Dan] tried to design a hypocycloid gear but couldn’t get a $3000 prototype to work. Although the hypocycloid is out, he did manage to build a strange differential pan/roll mechanism for the wrist of the arm. It really is a thing of beauty, and with the engineering [Dan] has put into it, it’s a very useful tool.
If you’d like to meet [Dan]’s robot arm in person, he’ll be at the 2015 NYC Maker Faire this weekend. Check out [Dan]’s Hackaday Prize video for his robot arm below.
Continue reading “Hackaday Prize Semifinalist: An Affordable Robotic Arm”
You’ve built the perfect robotic arm. How do you drive it? If you are [angrymop] you interface a 3D mouse from 3DConnexion via a few microcontroller boards. The Spacenavigator mouse is a staple anywhere professional CAD people are working, and it looks like it is a natural fit for a robot arm.
According to [angrymop], the Raspberry Pi can read the mouse’s commands via /dev/hidraw (that’s the raw human interface device). Each motion generates two lines of output. Each line has a unique identifying byte and values corresponding to the axis positions.
The Raspberry Pi then uses an SPI interface to talk to an ARM microcontroller and that drives the servos. The arm (the robot arm, not the processor) itself is well done, made from Lego Technic parts and common RC servos. Not that this is the most amazing thing we’ve ever seen built from Technic, but it is still pretty impressive.
You have to wonder if other 3D controllers might be useful for controlling robot arms or how the Spacenavigator would do controlling a bigger, more capable arm. Then again, maybe this arm would be the right size to build something inspired by Escher.
Continue reading “3D Mouse Drives Robot Arm”
With a background in software engineering, [Kris Temmerman] decided to make a physical demonstration of his knowledge in the form of a six axis robotic arm… the final product is a delicious display of mechanical eye candy.
Built from mostly aluminum stock, [Kris] machined the bulk of his parts with a CNC mill which he picked up for cheap from China. These custom pieces coupled with some hefty stepper motors ensure the arm’s accuracy as it twists freely and slides along the gantry it’s mounted to. Though the majority of the arm is metal, the hand at the end of his robot was built with 3D printed parts and can be switched out with the future attachments [Kris] plans to design. This classic gripper piece is driven separately with its own Arduino brain controlling the individual servos in the fingers.
Each finger includes some load bearing sensors which [Kris] harvested from an old scale so that the gripper can tell whether or not it has a hold of an object without crushing it. To orchestrate the robot’s movement, he wrote some nice looking software in C++ which visualizes the inverse kinematics at work in each point of articulation. For the sake of demonstrating his creation in action, he whipped up a basic demo that can locate and move colored blocks laid at random on a surface. A small camera mounted on the hand determines the orientation of the blocks relative to the machine so that the wrist can rotate itself in the proper alignment in order to pick them up.
[Kris] documented the build of his robot in a fascinating speed video which includes footage of the finished arm in action at the end:
Continue reading “This Home-Made 6-Axis Robotic Arm is Quite the Looker”