We’ve seen quite a few clocks that write the time out with a pen or marker. If you think about it, this really isn’t a great solution; every whiteboard marker will dry out in a day or two, and even if you’re using a pen, that’s still eventually going to run out of ink.
[ekaggrat] wanted a drawing clock that didn’t have these problems, and after taking a look at a magnetic drawing board, was struck with inspiration. The result is a clock that will perpetually write the time. It’s a revision of one of his earlier builds and looks to be much more reliable and mechanically precise.
A clock that writes time needs some sort of surface that won’t degrade, but can be written to over and over again. Whiteboards and glass won’t work, and neither will anything with ink. The solution to this problem was found in a ‘magnetic writing board’ or a Magna Doodle. These magnetic writing boards have a series of cells encapsulating iron filings. Pass a magnet over one side of the board, and a dot of filings appear. Pass a magnet over the opposite side of the board, and the filings disappear.
[ekaggrat]’s time-writing robot consists of a small Magna Doodle display, a robotic arm controlled by two stepper motors, and two solenoids on the end of the arm. The kinematics come from a helpful chap on the RepRap forums, and with the ATmega644 and two stepper drivers, this clock can write the time by altering the current flowing through two solenoids.
A video is the best way to experience this project, and you can check that out below.
Continue reading “Robot Clock Writes Time Over and Over and Over”
Meet Marty. He’s a pumpkin that has been fitted out with a moving eyes, tongue and an expression of malevolent glee. You would probably assume that this is all driven by servos, right? Nope: Marty is driven by an old-fashioned crank mechanism, designed and built by [Ben Brandt].
He wanted to make something that could be driven by a hand crank. Of course, there is nothing stopping you from throwing a motor on the back to drive the mechanism, but [Ben] wanted the internals to be fireproof so he could light it with a candle. His mechanism, built from old bits of wire and sheet metal, is not flammable or adversely affected by heat like a motor and power supply would be. He succeeded admirably, and he has also done an excellent job of documenting the process to providing handy tips on creating a mechanical pumpkin-based monstrosity.
Those hackers down with a little electronic wet work you should start building their LED-integrated Jack-O-Lantern now. These things take a lot of time turn out.
Continue reading “Hand Cranking the Malevolent Mechanical Pumpkin”
You can’t be bothered to sign up for a free parts.io account? Fine. You also don’t want to sign in each time you need to look up a component? Got it. You’ve made your point and the folks over at parts.io have made it so.
When the parts.io electronic component search engine was opened up for public use we covered it and gave you the rundown. Some of our readers left comments about things they were unhappy with regarding the parts.io system. Surprisingly, signing in was the most frequently voiced concern. It looks like your complaints were not taken lightly and you no longer have to register with the site to unlock all the parametric search data. There is still some added value to having an account like saving parts to a list for later use or you could get involved by joining the parts.io community on the forum.
Now we just need a parts search that knows what we want without having to actually choose parameters.
Full Disclosure: Parts.io is produced by Supplyframe Inc. Hackaday is an Editorially Independent part of Supplyframe.
It is hard enough to beat computers at games like chess. Now robotics engineers at the Ishikawa Watanabe Laboratory in Japan have created a janken robot that wins every time (if you didn’t know, janken is the Japanese name for rock-paper-scissors). How can it win every time? Easy. It cheats.
The janken robot evolved through three different versions. In the first version, the robotic hand would note the human player’s hand with a high-speed camera and then move the hand to a winning counter play with about a 20 millisecond delay. In the second version, the delay was greatly reduced.
However, in the third version, the robot uses a scanning technique to capture an entire field of view and determines what play the human is making. Again, a winning counter play is instantly produced by the robotic hand.
Continue reading “Robot Cheats at Rock Paper Scissors”
Video arcades may be a thing of the past, but they’re still alive, well and were ready to play at this year’s World Maker Faire. The offerings weren’t old favorites, all were brand new games many being shown for the first time like the long-awaited VEC9. The Hall of Science building was filled with cabinets and no quarters were necessary, all were free-play.
Death By Audio Arcade was there in force with games like Particle Mace and Powerboat Italia ’88. Our personal favorite was Nothing Good Can Come of This. [Michael P. Consoli] devised a simple game: Two players in an empty room. A bullet drops from a hole in the ceiling, followed by a gun shortly thereafter. What happens next is up to the players. The simple graphics and gameplay give this title its charm. [Michael] was showing off a new stand-up cabinet for the game this year. He built the entire thing himself, working until the wee hours before load-in at Maker Faire.
[Batsly Adams], [Todd Bailey], and [Mike Dooley] teamed up to create what may be the first new vector arcade in decades. VEC9 has been teased for over 2 years. They’ve finally wrapped this game up and showed it off at the faire. VEC9 started with an old
Asteroids vector monitor found by [Batsly].
Continue reading “Arcades: Don’t Call it a Comeback”
The philosopher in the street, who has not suffered a course in quantum mechanics, is quite unimpressed by the [Einstein-Podolsky-Rosen] correlations. He can point to many examples of similar correlations in everyday life. The case of Bertlmann’s socks is often cited. Dr. Bertlmann likes to wear two socks of different colours. Which colour he will have on a given foot on a given day is quite unpredictable. But when you see that the first sock is pink you can be already sure that the second sock will not be pink. Observation of the first, and experience with Bertlmann, gives the immediate information about the second. There is no accounting for tastes, but apart from that there is no mystery here. And is this [Einstein-Podolsky-Rosen] business just the same?
John Bell began his now famous paper with the above paragraph. The Bell Inequality started off like so many other great theories in science – as a simple thought experiment. Its conclusions were not so simple, however, and would lead the way to the end of Einstein’s idea of local hidden variables, and along with it his hopes for a deterministic universe. In this article, we’re going to look at the Bell inequality in great detail. Our guide will be a chapter from Jim Baggots’ The Quantum Story, as it has one of the best descriptions of Bell’s theory I’ve ever read.
Continue reading “Bertlmann’s Socks and the Nature of Reality”
One of our avid readers, [Niklas Melton] loves RC planes. After getting into 3D printing, the next logical step was to start building is own planes… And now he’s done it!
He calls it the Air-Form 1 Micro RC plane, paying homage to the FormLabs resin printer he used. All of the parts except for the electronics were printed using a tough resin. It’s designed to take balsa wood wings into clips he designed into the parts. A 150mAh battery provides the power with a motor that exerts about 54g of thrust — not bad considering the entire thing only weighs 60g! Unfortunately he doesn’t have any video clips of it flying, though he assures us it does indeed fly — if you’re interested in building your own, he’s uploaded all the files to a page on Thingiverse.
As more advanced 3D printers come down in price, like the SLA technology, it becomes possible to design and 3D print even more complex parts. Some of the resins available have now some pretty amazing properties. One of our readers replaced a servo spline gear with one he printed — which works even better than the original!