Tables Are Turned As Robots Assemble IKEA Furniture

June 19, 2018 by Brian McEvoy 15 Comments

Hackaday pages are rife with examples of robots being built with furniture parts. In this example, the tables are turned and robots are the masters of IKEA pieces. We are not silly enough to assume that these robots unfolded the instructions, looked at one another, scratched their CPUs, and began assembling. Of course, the procedure was preordained by the programmers, but the way they mate the pegs into the ends of the cross-members is a very human thing to do. It reminds us of finding a phone charging socket in the dark. This kind of behavior is due to force feedback which tell the robots when a piece is properly seated which means that they can use vision to fit the components together without sub-millimeter precision.

All the hardware used to make the IKEA assembler is publicly available, and while it may be out of the typical hacker price range, this is a sign of the times as robots become part of the household. Currently, the household robots are washing machines, smart speakers, and 3D printers. Ten years ago those weren’t Internet connected machines so it should be no surprise if robotic arms join the club of household robots soon. Your next robotics project could be the tipping point that brings a new class of robots to the home.

Back to our usual hijinks, here is a robot arm from IKEA parts and a projector built into a similar lamp. or a 3D printer enclosed in an IKEA cabinet for a classy home robot.

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FPV-Rover 2.0 Has 3D Printed Treads And Plenty Of Zip

June 17, 2018 by Al Williams 11 Comments

[Markus_p] has already finished one really successful 3D printed tracked robot build. Now he’s finished a second one using standard motors and incorporating what he learned from the first. The results are pretty impressive and you can see a video demo of the beast, below.

Most of the robot is PLA, although there are some parts that use PETG and flex plastic. There is an infrared-capable camera up front and another regular camera on the rear. All the electronics are pretty much off the shelf modules like an FPV transmitter and an electronic controller for the motors. There’s a servo to tilt the camera, as you can see in the second video.

The body fits together using nuts and magnets. The robot in the video takes a good beating and doesn’t seem to fall apart so it must be sufficient. What appealed to us was the size of the thing. It looks like it would be trivially easy to mount some processing power inside or on top of the rover and it could make a great motion base for a more sophisticated robot.

We’ve seen some similar projects, of course. This tracked robot uses mind control. And OpenWheel is a great place to get treads and other locomotion designs.

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A 3D-Printed Robot Actuator

June 16, 2018 by Jenny List 18 Comments

Somehow, walking robots at our level never really seem to deliver on the promise that should be delivered by all those legs. Articulation using hobby servos is simple enough to achieve, but cumbersome, slow, and not very powerful. [Paul Gould] has a plan to make a better, 3D-printed articulated robot actuator.

His solution is both novel and elegant, a fairly conventional arm geometry that has at its joints a set of brushless motors similar to but a little larger than the kind you might be more familiar with on multirotors, paired with 3D-printed cycloidal gearboxes. Magnetic encoders provide the necessary positional feedback, and the result is a unit that is both compact and powerful.

With such a range of small brushless motor controllers on the market, it’s at first sight unexpected that he’s designed his own controller board. But this gives him complete control over his software, plus the CAN bus that ties everything together. He’s given us a video which we’ve placed below the break, showing the build process, the impressive capabilities of his system, and a selection of builds including a robot dog complete with tail. This is definitely a project to watch.

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Making Robot Snakes That Slither, Sidewind, And Strike

June 14, 2018 by Steven Dufresne 5 Comments

[Will Donaldson] has been making robot snakes of all sorts. One of his snakes hugs the ground, slithering across it with a sine wave motion. Flipping it on its side and calling different code, that same snake also moves like an inchworm. Another of his snakes lifts parts of itself upward to move sideways across the ground, again using sine waves.

At first, his slithering snake would only oscillate in place on the floor. Looking more closely at biological snakes, he found that part of the reason they moved forward was due to their scales. The scales move smoothly over the ground in one direction but grip when pushed backward or sideways. He also found work done at Harvard University where they combined pumped air and papercraft to make scales which change shape. And so [Will] designed and 3D printed some scales for his snake. However, as you can see in the video below, they didn’t work on carpet.

His success came when he added wheels to each segment. They didn’t work like a car, there was no engine turning the wheels. Instead, they acted more like scales, rotating freely in one direction and gripping when pushed sideways. This success also allowed him to add a parameter to his code for turning left or right.

As we said above, he can flip the ground hugger sideways and run it as an inchworm and he also has a working sidewinder snake variation. The sidewinder can even lift up its head and strike like a cobra. Check out his hackaday.io page if you want to make your own. He’s provided STL files, code, and construction details.

[Will] has a lot of future plans for his snakes. Currently, they’re tethered to a modified ATX power supply but he’d like to incorporate LiPo batteries into the snakes instead. His original goal was to make a tree climbing snake like the one by the Biorobotics lab at Carnegie Mellon University (updated link for the article) but his first snake wasn’t long enough. He still plans on pursuing that as well as an underwater electronic eel. There seems to be no limit to the things he can try. For now, check out the video below to see his successes and his failures so far. Maybe you even have some suggestions for those tricky scales. The undersides of his snake’s segments do seem modular, lending themselves to experimentation.

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Rescuing K-9

June 13, 2018 by Jenny List 50 Comments

Fans of the long-running and ever-fantastic British TV show Dr. Who will no doubt hold a soft spot in their hearts for the Doctor’s little robot companion. No, not one of his many human sidekicks, we’re talking about K-9, the angular dog-like android that burst onto British screens back in 1977.

There were a number of original [K-9] props made by the BBC, and these were eventually sold by the corporation. One found its way to Abertay University, and it was there that [Gary Taylor], a computer science student found it. Sadly the years had not been kind to the robotic mutt, in particular water from a roof leak had damaged its internals beyond repair. With little more than the fibreglass shell to work with, he set out to rebuild K-9 and make the task the subject of his dissertation.

The original robo-dog was little more than a 1970s remote-controlled car, but its upgrades bring it firmly into the 21st century. At its heart is the inevitable Raspberry Pi 3, coupled with an Arduino mega 2560 that handles motor control and interfacing to an array of ultrasonic sensors. The Pi’s Bluetooth radio talks to an app on an Android phone, that serves as the K-9’s controller. All of which makes for an impressive upgrade, but we hope has disturbed as little of the original prop work as possible

Not everyone is lucky enough to find an original K-9, but for those destined for classic BBC prop disappointment there is always the possibility that you could build your own.

James Bruton's openDog inverse kinematics

[James Bruton] Is Making A Dog: OpenDog Project

June 11, 2018 by Steven Dufresne 32 Comments

There was a time when a two-legged walking robot was the thing to make. But after seeing years of Boston Dynamic’s amazing four-legged one’s, more DIYers are switching to quadrupeds. Now we can add master DIY robot builder [James Bruton] to the list with his openDog project. What’s exciting here is that with [James’] extensive robot-building background, this is more like starting the challenge from the middle rather than the beginning and we should see exciting results sooner rather than later.

James' motor and ball screws — James’ motor and ball screws

Thus far [James] has gone through the planning stage, having iterated through a few versions using Fusion 360, and he’s now purchased the parts. It’s going to be about the same size as Boston Robotic’s SpotMini and uses three motors for each leg. He considered going with planetary gearboxes on the motors but experienced a certain amount of play, or backlash, with them in his BB-9E project so this time he’s going with ball screws as he did with his exoskeleton. (Did we mention his extensive background?)

Each leg is actually made up of an upper and lower leg, which means his processing is going to have to include some inverse kinematics. That’s where the code decides where it wants the foot to go and then has to compute backwards from there how to angle the legs to achieve that. Again drawing from experience when he’s done it the hard way in the past, this time he’s designed the leg geometry to make those calculations easy. Having written up some code to do the calculations, he’s compared the computed angles with the measurements he gets from positioning the legs in Fusion 360 and found that his code is right on. We’re excited by what we’ve seen so far and bet it’ll be standing and walking in no time. Check out his progress in the video below.

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High Voltage Switching With MOSFETs

June 10, 2018 by Al Williams 9 Comments

Using a MOSFET as a switch is generally pretty simple. Make the gate voltage sufficient with respect to the source and current flows through the channel. However, if you are switching higher voltages, you may need some additional circuitry to protect the device’s gate and possibly the microcontroller driving the whole thing, too. [Lewis] discusses high voltage switching in the latest in his series of videos dealing with MOSFETs. You can see the video below.

You’ll see in the video a breadboard setup driving a 50 V load and also a higher-voltage H-bridge. There are three major topics covered: Using an optoisolator, using a gate bleeder resistor, and using a zener diode to limit gate voltage.

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