Robots Hacks

2349 Articles

Pulleys Within Pulleys Form A Unique Transmission For Robots

September 25, 2017 by 36 Comments

After a couple of millennia of fiddling with gears, you’d think there wouldn’t be much new ground to explore in the field of power transmission. And then you see something like an infinitely variable transmission built from nested pulleys, and you realize there’s always room for improvement.

The electric motors generally used in robotics can be extremely efficient, often topping 90% efficiency at high speed and low torque. Slap on a traditional fixed-ratio gearbox, or change the input speed, and efficiency is lost. An infinitely variable transmission, like [Alexander Kernbaum]’s cleverly named Inception Drive, allows the motor to stay at peak efficiency while smoothly changing the gear ratio through a wide range.

The mechanism takes a bit of thought to fully grok, but it basically uses a pair of split pulleys with variable spacing. The input shaft rotates the inner pulley eccentrically, which effectively “walks” a wide V-belt around a fixed outer pulley. This drives the inner pulley at a ratio depending on the spacing of the pulley halves; the transmission can shift smoothly from forward to reverse and even keep itself in neutral. The video below will help you get your head around it.

We’ve seen a couple of innovative transmissions around here lately; some, like this strain-wave gear and this planetary gearbox, are amenable to 3D printing. Looks like the Inception Drive could be printed too. Hackers, start your printers and see what this drive can do.

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Cronk The Gonk Droid

September 20, 2017 by 7 Comments

The ‘Gonk’ droids from the Star Wars universe are easy to overlook, but serve the important function of mobile power generators. Here on Earth, [bithead942]’s life-size replica droid fulfills much the same purpose.

Cronk — functionally an oversized USB charging hub with a lot of bells and whistles — is remotely controlled by a modified Wii Nunchuck very controller similar to the one [bithead942] used to control his R2-D2. With the help of an Adafruit Audio FX Mini, an Adafruit Class D 20W amp, and two four-inch speakers, the droid can rattle off some sound effects as it blows off some steam(really, an inverted CO2 duster). An Arduino Mega acts as Cronk’s brain while its body is sculpted from cast-able urethane foam for its light weight and rigidity. It also houses a FPV camera, mic, and DVR so it can be operated effectively from afar.

And, it can dance!

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Winch Bot Records Hacks And Cats

September 14, 2017 by 14 Comments

Some people are better than others when it comes to documenting their hacks. Some people, like [Micah Elizabeth Scott], aka [scanlime], set the gold standard with their recordings. Hacking sessions with the Winch Bot have been streamed regularly throughout the build and this is going to lead to a stacking effect in her next projects because the Winch Bot was designed to record hacking sessions. Hacking video inception anyone? Her Winch Bot summary video is after the break.

The first part of this build, which she calls the Tuco Flyer, was [Micah Elizabeth Scott]’s camera gimbal hack which we already covered and is a wonderful learning experience in itself. She refers to the gimbal portion as the “flyer” since it can move around. The Winch Bot contains the stationary parts of the Tuco Flyer and control where the camera will be in the room.

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Robot Graffiti

September 13, 2017 by 11 Comments

There’s talk of robots and AIs taking on jobs in many different industries. Depending on how much stock you place in that, it might still be fair to say the more creative fields will remain firmly in the hands of humans, right?

Well, we may have some bad news for you. Robots are now painting our murals.

Estonian inventor [Mihkel Joala] — also working at SprayPainter — successfully tested his prototype by painting a 30m tall mural on a smokestack in Tartu, Estonia. The creative procedure for this mural is a little odd if you are used to the ordinary painting process: [Joala] first takes an image from his computer, and converts it into a coordinate grid — in this case, about 1.5 million ‘pixels’. These pixels are painted on by a little cart loaded with five colours of spray paint that are able to portray the mural’s full palette once combined and viewed at a distance. Positioning is handled by a motor at the base of the mural controlling the vertical motion in conjunction with tracks at the top and bottom which handle the horizontal motion.

For this mural, the robot spent the fourteen hours trundling up and down a set of cables, dutifully spraying the appropriate colour at such-and-such a point resulting in the image of a maiden cradling a tree and using thirty cans of spray paint in the process.

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Educational Robot For Under $100

September 6, 2017 by 20 Comments

While schools have been using robots to educate students in the art of science and engineering for decades now, not every school or teacher can afford to put one of these robots in the hands of their students. For that reason, it’s important to not only improve the robots themselves, but to help drive the costs down to make them more accessible. The CodiBot does this well, and comes in with a price tag well under $100.

The robot itself comes pre-assembled, and while it might seem like students would miss out on actually building the robot, the goal of the robot is to teach coding skills primarily. Some things do need to be connected though, such as the Arduino and other wires, but from there its easy to program the robot to do any number of tasks such as obstacle avoidance and maze navigation. The robot can be programmed using drag-and-drop block programming (similar to Scratch) but can also be programmed the same way any other Arduino can be.

With such a high feature count and low price tag, this might be the key to getting more students exposed to programming in a more exciting and accessible way than is currently available. Of course, if you have a little bit more cash lying around your school, there are some other options available to you as well.

The (Robot) Body Electric

September 4, 2017 by 13 Comments

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.

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Poetry In Motion With A Sand-Dispensing Dot Matrix Printer

September 3, 2017 by 12 Comments

Hackaday gets results! Reader [John] saw our recent Fail of the Week post about a “sand matrix printer” and decided to share his own version, a sand-dispensing dot matrix printer he built last year.

Granted, [John]’s version is almost the exact opposite of [Vjie Miller]’s failed build, which sought to make depressions in the sand to print characters. [John]’s Sandscript takes a hopper full of dry, clean sand and dispenses small piles from six small servo-controlled nozzles. The hopper is mounted on a wheeled frame, and an optical encoder on one wheel senses forward motion to determine when to open each nozzle. As [John] slowly walks behind and to the side of the cart, a line of verse is slowly drizzled out onto the pavement. See it in action in the video below.

More performance art piece than anything else, we can see how this would be really engaging, with people following along like kids after the [Pied Piper], waiting to find out what the full message is. There’s probably a statement in there about the impermanence of art and the fleeting nature of existence, but we just think it’s a really cool build.

We’ve featured other sand writers before, like this high-resolution draw bot that also dispenses sandy verses, or this literal beach-combing art bot. Guess there’s just something about sand that inspires artists and hackers alike.

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