Artist Inadvertently Builds Hodoscope

March 6, 2015 by 31 Comments

A Hodoscope is an instrument used to determine the trajectory of charged particles. It’s built out of a three-dimensional matrix of particle detectors – either PIN diodes or Geiger tubes – arranged in such a way that particles can be traced along coincident detectors, revealing their trajectory.

This is not a hodoscope. It’s a chandelier. This chandelier is made of 92 individual Geiger tubes, each connected to a single LED fixture and a speaker. When a charged particle flies through the room and hits a Geiger tube, the light fixture lights up, a ‘click’ plays on the speaker, and the entire room is enveloped in light for a short moment in time. If, however, that charged particle continues on to another Geiger tube, the trajectory of the particle can be deduced.

The purpose of the installation – beside just being art or something – is to show the viewer sources of radiation and normal levels of radioactivity due to terrestrial and cosmic sources. Of course the spacing of these detectors is rather large – it’s made to fit in a gallery – and there is no connection between the detectors, making a coincident circuit impossible. If you want a real hodoscope, here you go.

This installation can be seen at the Burchfield Penney Art Center in Buffalo, NY through April 12. If you’re in the area, go there and eat a banana. Video below. Thanks [David] for the tip.

Continue reading “Artist Inadvertently Builds Hodoscope” →

Cheap, Dirty And Perfect V-Groove Foam Cutter

March 5, 2015 by 13 Comments

If the only tool you have is a hammer, everything looks like a nail. Conversely, if you have the right tool for every job, it makes the difference between pro and amateur. [ftregan] needs to cut perfect V-grooves in foam for many of his projects, especially building RC planes. He wasn’t too satisfied with the results using his Xacto knife. And a proper tool was going to set him back by almost $25, but following that example he built his own version of the tool for much less.

Two pieces of wood cut at a 45 degree angle are held between two flat support pieces. A pair of regular shaving blades form the cutting elements. While it looks simple, it’s important to get the angles and blade directions correct. A central wooden wedge holds the two blades in place. He also added a small guide marker that let’s you cut precise straight grooves. [ftregan] built the tool to allow cutting 6mm thick foam but given that it’s so quick and cheap to build, we guess it’s easy to make a few of these to allow cutting different thicknesses of foam. We’re sure that many of you will find different or better ways of doing this, but considering [ftregan] spent just 15 minutes cooking this up, it’s not too bad, especially since the results are mighty good.

Another method of cutting foam is with hot wire. Check out this DIY Foam Cutter that we featured earlier.

Incubating Resin Prints Through The Chilly Months

March 5, 2015 by 5 Comments

FormLabs resins operate best between the comfortable temperature range of 18 – 28°C (64 – 82°F). For many of us experiencing the chillier weather these days, our garage workshops can easily drop below those temperatures and cause our prints to fail. Rather than hunker down for the freeze and wait for the world outside to defrost, [MarkStrohbehn] has discovered a budget heating technique that heats the print chamber from the inside instead.

This trick comes in two parts. First, to bring the temperature up, [Mark] installed an egg incubator inside the chamber using a powerful magnet attached to the fixture containing the lead screw. Next, to maintain the warm temperature, he’s taped together an insulating jacket composed of several layers of off-the-shelf mylar emergency blankets. Finally, he’s managed to slip the egg incubator power cable cleanly under the FormLabs lid without triggering the open-lid sensor. This hack is staggeringly simple but effective at reducing the odds of failed prints through the cold weather. Best of all, the modifications are far less invasive than other upgrades made to 3D printers, as it requires no modification of the Form1+. For those of us who haven’t seen the sun in a few months, rest assured that you can still churn out parts.

Big Jacobs Ladder

11,000 Volt Jacob’s Ladder Sounds Like A Lightsaber

March 5, 2015 by 35 Comments

In the high-voltage world, a Jacob’s ladder is truly a sight to behold. They are often associated with mad scientist labs, due to both the awesome visual display and the sound that they make. A Jacob’s ladder is typically very simple. You need a high voltage electricity source and two bare wires. The wires are placed next to each other, almost in parallel. They form a slight “V” shape and are placed vertically. The system acts essentially as a short-circuit. The voltage is high enough to break through the air at the point where the wires are nearest to each other. The air rises as it heats up, moving the current path along with it. The result is the arc slowly raising upwards, extending in length. The sound also lowers in frequency as the arc gets longer, and once [Gristc] tuned his system just right the sound reminds us of the Holy Trilogy.

We’ve seen these made in the past with other types of transformers that typically put out around 15,000 Volts at 30mA. In this case, [Gristc] supersized the design using a much beefier transformer that puts out 11,000 Volts at 300mA. He runs the output from the transformer through eight microwave oven capacitors as a ballast. He says that without this, the system will immediately trip the circuit breakers in his house.

In the demo video below, you can see just how large the arc is. It appears to get about 10 inches long before breaking with a sound different from any Jacob’s ladders we’ve seen in the past as well. Continue reading “11,000 Volt Jacob’s Ladder Sounds Like A Lightsaber” →

Fail Of The Week: Hair Dryer As Light Switch

March 5, 2015 by 69 Comments

Home electrical, it’s really not that hard. But when you’re dealing with the puzzles left for your by someone else things can get really weird. [Daniel’s] sister and her husband ran into this recently. The video demonstration of their fail includes a lot of premature laughter, but it’s worth hanging in there… you’ll quickly see why she can’t contain her amusement.

The project at hand is a replacing a bathroom fan with a simple light fixture. Once the swap was made the light switch works just as anticipated. But a second switch which used to control a different light now behaves strangely. It doesn’t activate the original light, but instead switches the new fixture. Even stranger is that the original switch apparently now acts as a bizarre dimmer when the second switch is on. That’s odd, but the coup d’état of the fail is when they plug in a hair dryer and switching it on illuminates the light but doesn’t activate the hair dryer.

As with all Fail of the Week segments, the goal here is not to criticize but to commiserate. What do you think is causing this? We can’t wait to see what you come up with. Posting simple diagrams is encouraged (you can use HTML img tags in the comments). Ladies and gentlemen, start your conjecture.

Continue reading “Fail Of The Week: Hair Dryer As Light Switch” →

Revive The Demoscene With A LayerOne Demoscene Board

March 5, 2015 by 36 Comments

Demos, the demoscene, and all the other offshoots of computer arts had their beginning as intros for cracked Apple II, Speccy, and Commodore 64 games. Give it a few years, and these simple splash screens would evolve into a technological audio-visual experience. This is the birth of the demoscene, where groups of programmers would compete to create the best demonstration of computer graphics and audio.

For one reason or another, this demoscene was mostly confined to Europe; even today, 30 years after the Commodore 64, the North American demoscene is just a fraction of the size of the European scene. A very cool guy named [Arko] would like to change that, and to that end he built the LayerOne Demoscene Board.

If there is a problem with the modern demo scene, it’s that the hardware that’s usually used – C64s, Ataris, Spectrums, and Amigas – are old, somewhat rare, and dying. There’s also the fact that artists have been working on these old machines for decades now, and every single ounce of processing power and software trickery has been squeezed out of these CPUs. [Arko]’s board is a ground-up redesign of what a board that plays demos should be. There’s only one chip on the board – a PIC24F with three graphics acceleration units, color lookup tables, and the ability to output 16-bit VGA video up to 640×480 with 8-bit audio.

The first official competition with the LayerOne Demoscene Board will be at the 2015 LayerOne conference in Monrovia, CA on May 23. There are a few categories, including 4k and 64k JavaScript, Raspberry Pi, the LayerOne board, and a ‘Wild’ category. If you want to take a processor out of a toaster and make a demo, this is the category you’ll be entering. Of course Hackaday will be there, and we’ll be recording all the demos.

Below are a few examples of what the LayerOne Demoscene board can do, and you can also see a talk [Arko] gave at the Hackaday 10th anniversary party here. You can buy the Layerone Demoscene Board on the Hackaday Store

Continue reading “Revive The Demoscene With A LayerOne Demoscene Board” →

Power Meter

Solar Panel System Monitoring Device Using Arduino

March 5, 2015 by 10 Comments

[Carl] recently upgraded his home with a solar panel system. This system compliments the electricity he gets from the grid by filling up a battery bank using free (as in beer) energy from the sun. The system came with a basic meter which really only shows the total amount of electricity the panels produce. [Carl] wanted to get more data out of his system. He managed to build his own monitor using an Arduino.

The trick of this build has to do with how the system works. The panel includes an LED light that blinks 1000 times for each kWh of electricity. [Carl] realized that if he could monitor the rate at which the LED is flashing, he could determine approximately how much energy is being generated at any given moment. We’ve seen similar projects in the past.

Like most people new to a technology, [Carl] built his project up by cobbling together other examples he found online. He started off by using a sketch that was originally designed to calculate the speed of a vehicle by measuring the time it took for the vehicle to pass between two points. [Carl] took this code and modified it to use a single photo resistor to detect the LED. He also built a sort of VU meter using several LEDs. The meter would increase and decrease proportionally to the reading on the electrical meter.

[Carl] continued improving on his system over time. He added an LCD panel so he could not only see the exact current measurement, but also the top measurement from the day. He put all of the electronics in a plastic tub and used a ribbon cable to move the LCD panel to a more convenient location. He also had his friend [Andy] clean up the Arduino code to make it easier for others to use as desired.