Choreographed Iron Dust Dances to the Beat

Up on the second level of World Maker Faire’s main hall, one could hear Technotronic’s hit “Pump up the Jam” playing again and again. We were expecting breakdancing robots, but upon investigating, what we found was something even better. [David Durlach] was showing off his Choreographed Iron Dust, a 9 x 9 grid of magnets covered in iron filings. The filings swayed and danced to the beat of the music, at times appearing more like ferrofluid than a dry material. Two LED lights shined on the filings from an oblique angle. This added even more drama to the effect as the light played on the dancing spikes and ridges.

While chatting with [David] he told us that this wasn’t a new hack. Choreographed Iron Dust made its debut at the Boston Museum of Science back in 1989. Suddenly the 80’s music made more sense! The dust’s basic control system hasn’t changed very much since the 1980’s. The magnets are actually a stack of permanent and electromagnets. The permanent magnet provides enough force to hold the filings in place. The electromagnets are switched on to make the filings actually dance.

Since it was designed in 1989, there were no Arduinos available. This project is powered by the most hacker friendly interface of the era: the PC’s parallel port. As one might imagine, [David] has been having a hard time finding PC’s equipped with parallel ports these last few years.

[David] wasn’t just showing off iron dust. Having spent so much time painstakingly animating the iron filings for various customers, he knew there had to be a better way. He’s come up with ChoreoV, a system which can take recorded video, live performances, or even capture a section of a user’s screen. The captured data can then be translated directly into light or motion on an art piece.

The Abovemarine

Over the course of a few weeks, [Adam] trained his betta fish, [Jose], to jump out of the water to snatch food off his finger. An impressive display for a fish, but being able to train his small aquatic friend got [Adam] thinking. What’s stopping [Jose] from interacting his environment even more? The abovemarine was born.

The abovemarine is a robotic platform specifically built for [Jose]’s aquarium. Below, three omni wheels drive the entire aquarium in any direction. A computer running OpenCV, a webcam, and a few motors directs the abovemarine in whatever direction [Jose] wants to go. Yes, it’s a vehicle for a fish, and that’s awesome.

[Adam] put a lot of work into the creation of the abovemarine, and was eventually able to teach [Jose] how to control his new home. In the videos below, you can see [Jose] roaming the studio and rolling towards the prospect of food.

Because [Jose] is a Siamese fighting fish and extremely territorial when he sees other males of his species, this brings up the idea of a version of Battlebots with several abovemarines. They’re in different tanks, so we don’t know what PETA would think of that, but we do expect it to show up in the Hackaday tip line eventually.

Continue reading “The Abovemarine”

Homemade E-Cigarette Vaporizer

Extensive research shows that tobacco kills. This is common knowledge as of late, which has prompted a flurry of anti-smoking ads to flood in. Regular smokers are now reconsidering their smoking patterns and are looking at healthier alternatives. Among those options are electronic cigarettes that vaporize flavorful liquid into smooth drags of smoke.

Prices for these devices can range anywhere from $40 to $240, which can be quite expensive for those on a budget. So instead of buying one, [MrRedBeard] decided to create his own DIY electronic cigarette contraption out of an Altoids can.

The approximate cost (not including batteries) is about $12. This covers the 5 Amp adjustable voltage regulator and the 500 ohm potentiometer that is best used for a rig like this. The wattage is what drives the heat giving it a more consistent vapor stream of cloud smoke.

For more e-cigarette hacks, check out these ones powered by an NES controller and this vaporizer that can send smells…in space!

Continue reading “Homemade E-Cigarette Vaporizer”

The Reason Dead Batteries Bounce

For the last few years, very well-informed people have been able to tell if an alkaline battery is good or not simply by dropping them. When dropped from an inch or two above a hard surface, a good battery won’t bounce, and will sometimes land standing up. A dead battery, on the other hand, will bounce. Thanks to [Lee] and a few of his friends, we now know why this happens.

While hanging out with a few of his buddies, [Lee] was able to condense all the arguments on why dead batteries bounce to two theories. The first theory, the ‘bounce theory’ said dead batteries had an increase in outgassing in the battery, increasing the pressure in the battery, which increases the spring constant of the battery itself. The second theory, the ‘anti-bounce theory’, said the gel-like properties of the electrolyte worked as a sort of mass damper.

[Lee] designed an experiment to test the outgassing ‘bounce theory’ of bouncing batteries. Instead of dropping a battery, an object – in this case a brass slug – was dropped onto both good and bad batteries. There was no difference. Even after holes were drilled to vent any gasses inside the battery, the brass slug bounced off both good and bad batteries the same way.

This means the reason dead alkaline batteries bounce is due to the electrolyte. [Lee] cut open a few AA cells and found the electrolyte in a good battery was a mushy mess of chemicals. In the dead battery, this same electrolyte hardened into a solid mass. [Lee] compares this to an anti-bounce hammer.

Finally, more than a year after most of us learned about bouncing dead batteries thanks to [Dave Jones]’ video, we have an answer. It’s a chemical change in the electrolyte that turns it from a goo to a solid that makes dead batteries bounce.

Continue reading “The Reason Dead Batteries Bounce”

radioshack phone dialer – red box

i thought i’d start out with this hack while we’re in beta, since it was one of the first ones that really got me interested in the way phones worked and how many consumer electronics can be used for new and educational things. a “red box” was a device that would simulate coins being dropped in to a pay-phone, hence free phone calls for many people until the phone systems changed. the most popular device to modify was a radioshack tone dialer, a simple solder of a 6.5536 mhz crystal was all it took and you could “drop” 5, 10 and 25 cents at a time to make calls.

Continue reading “radioshack phone dialer – red box”

Voices From the Past: Recovering Audio From Wire Recordings

wire recorder setup[Nick]’s grandfather was quite the old school hacker. In the 1940s, he built his own wire recorder and microphone to capture everything from his children’s Chirstmas wishes to his favorite songs and programs from the radio. Only 20 or so spools have survived and were doomed to silence until [Nick] was able to find a vintage wire recorder, restore it, and feed digitized audio into Audacity.

Once he restored one of the two machines that he was able to get his hands on, [Nick] was in business. Since his grandfather also rolled his own spools, [Nick] had to build a playback spindle that would hold them. His uncle found an old mechanical counter to do the job, which [Nick] secured to the workbench. He fed the output from the wire recorder’s playback head into a guitar pre-amp, effectively digitizing the audio for recording in Audacity.

After playing all the spools, he adjusted the levels where necessary and cleaned up the recordings. His biggest challenge was feeding the wires back on to their original spools, which he managed with an electric drill and a rubber grommet. Be sure to check out the mp3 clips on [Nick]’s page. If you’re in the mood for old audio hacking stories, here’s one about building a tape recorder in 1949.

Purely Mechanical Display Uses 804 Balls To Create a Kinetic Display

Whoa. That’s all we have to say about this art installation.

Oops, did we say art? Don’t let that three letter word scare you, because this project called Breaking Wave is nothing short of an absolutely incredible, fully mechanical, machine.

It’s kind of hard to tell in the picture, but there are 804 rusty spheres hanging from cables which make up the pixels of this display. Each of those cables could be attached to a servo for a very simple, digital-to-analog display — it’d be expensive, but you could display anything. But no, that’s not how this works. Instead of each of those cables is wrapped around a different size drum or roller, which are all connected to a large central hub motor driving a cam.

As the beastly hub-motor spins, the display morphs and changes shapes. It is all pre-programmed manually by varying the sizes of the rollers and the lengths of the cables, a mind numbing task of its own. What’s more, because it is three dimensional, you can only see the patterns if you’re standing in the right place at the right time.

Continue reading “Purely Mechanical Display Uses 804 Balls To Create a Kinetic Display”