We’re not ashamed to admit that we desperately want a pair of high-end industrial robot arms to play around with. We don’t know where we’d put them — maybe the living room? — but we know that we’d figure something out.
This demo aims to get Boy Scouts interested in robotics by applying the beastly arms to something that all kids love, learning to tie knots. (If you ask us, they’ve got it backwards.) Anyway, there are two videos embedded below for you to peek at.
We’re used to projects that take everyday household objects and modify or enhance them into new and exciting forms that their original designers never intended. A particular theme in this endeavour comes from the IKEA hacking community, who take the products of the Swedish furniture store and use them for the basis of their work.
A particularly inventive piece of IKEA hacking is a project from [anastas.car], a low-cost 3D-printed robot arm based on Ikea Tertial lamp. The lamp in question is a relatively inexpensive spring-balanced desk lamp that when looked at in another light has all the metalwork ready-cut for a 5 degrees of freedom robot arm when combined with 3D-printed servo holders for five servos at its joints. The resulting design has all files available on Thingiverse, and judging by the video we’ve posted below the break makes for a rather effective arm.
Building a simple robot arm is a lot more straightforward than it used to be. If you have a laser cutter, or a bit of cash and don’t mind waiting for postage, there are inexpensive kits like the MeArm. If you have a 3D printer, there are any number of 3D-printed designs for you to tackle. What if you need to satisfy your urge to build a robot arm really quickly, and you don’t have a laser cutter or 3D printer? You’ve got a pile of servos from that remote-control project, how can you make the rest?
If you are [roboteurs], you raid the stationery cupboard, and create an arm using rubber bands, paper clips, and binder clips. The binder clips grip the servo arms and hold the whole thing together, the rubber bands provide extra attachment , and the paper clips are bent to form the jaws. It’s not the prettiest or perhaps the most capable of arms, but it undeniably is an arm, and we’d doubt it could be done any more cheaply.
In this particular case, the arm serves as a demonstration piece for [roboteurs]’ Printabots Maker Kit for people without a 3D printer. It uses their controller board, but there is no reason why it could not be used with any other board capable of driving servos.
We’ve covered innumerable robot arms over the years, This one may be the cheapest, but another contender might be this cardboard arm. None of them, however, are as cool as this steam-powered Armatron toy.
Google showed the world that you could make a virtual reality headset from cardboard. We figure that might have been [Uladz] inspiration for creating a robotic arm also made out of cardboard. He says you can reproduce his design in about two hours.
You’ll need an Arduino and four hobby servo motors. The cardboard doesn’t weigh much, so you could probably use fairly small motors. In addition to the cardboard, there’s a piece of hardboard for the base and a few metal clips. You can control it all from the Arduino program or add an IR receiver if you want to run it by remote control. There’s a video of the arm–called CARDBIRD–in action, below.
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.
Last fall, I grabbed a robot arm from Robot Geeks when they were on sale at Thanksgiving. The arm uses servos to rotate the base and move the joints and gripper. These work well enough but I found one aspect of the arm frustrating. When you apply power, the software commands the servos to move to home position. The movement is sufficiently violent it can cause the entire arm to jump.
This jump occurs because there is no position feedback to the Arduino controller leaving it unable to know the positions of the arm’s servos and move them slowly to home. I pondered how to add this feedback using sensors, imposing the limitation that they couldn’t be large or require replacing existing parts. I decided to try adding accelerometers on each arm section.
Accelerometers, being affected by gravity when on a planet, provide an absolute reference because they always report the direction of down. With an accelerometer I can calculate the angle of an arm section with respect to the direction of gravitational acceleration.
Before discussing the accelerometers, take a look at the picture of the arm. An accelerometer would be added to each section of the arm between the controlling servos.
Continue reading “Taming Robot Arm Jump With Accelerometers”
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”
