Let’s Blow Up An Explosive Lightning Arrestor

December 22, 2015 by 37 Comments

Lightning is some nasty stuff. Luckily, it doesn’t have a very long lifespan. [BigClive] decided to tear down an 11KV lighting arrestor used in power distribution systems. The fiberglass core has silicone rubber water-shedding disks that make the unit look sort of floppy, but inside is some serious hardware.

To protect the circuit, metal oxide varistors shunt high voltage from a lightning strike to ground as you’d expect. The interesting part is how the device deals with failure. It would be a disaster if the device shorted the 11KV power line to ground for any length of time due to a fault. To prevent that problem, a resistor heats up when struck by lightning and triggers an explosive charge that disconnects the ground wire and releases a flag to indicate the failure.

[BigClive] triggered the charge in the video below. So if you like to see things explode in a bucket of water, you’ll enjoy the video.

Continue reading “Let’s Blow Up An Explosive Lightning Arrestor” →

The Scientific Implausibility Of Starkiller Base

December 22, 2015 by 112 Comments

This post contains spoilers for Star Wars: The Force Awakens. These spoilers won’t affect you if you haven’t seen the movie; they’re equivalent to saying, “in A New Hope there’s a moon sized battle station with a superlaser” and “someone gets a hand amputated with a lightsaber in a Star Wars movie”

A lot has happened in the Star Wars universe since the battle of Endor. The Empire is in ruins, and Yavin 5 and the forest moon of Endor both have new planetary ring systems. The Rebellion has given way to a new Galactic Republic, but there is a spectre of evil looming in the unknown areas of the galaxy: the First Order, a malevolent force that has built a planet-sized superweapon capable of destroying entire planetary systems from across the galaxy. The Starkiller gets its energy from harvesting entire suns, moving from one solar system to another to feed this massive weapon of terror.

We’ve had nearly forty years to argue the plausibility of the Death Star, lightsabers, parsecs as a unit of time, and hyperdrives. It’s time to pass the hallowed tradition of arguing over fictional spacecraft to a new generation. Starkiller Base is a cool idea, but does the science behind it hold up? No. It’s completely implausible. It makes for a great story, but it’s completely implausible.

Continue reading “The Scientific Implausibility Of Starkiller Base” →

Homemade Internal Combustion Engine – Sans Machine Shop

December 22, 2015 by 18 Comments

We’ve got a question for you:  If you were stuck in a basement, with nothing too much more than some copper pipe, solder, JB-Weld, and a few hand tools, do you think you could make a working 2-stroke motor? Well, [Makerj101] did just that, and the results are fan-freaking-tastic.

[Makerj101] began his journey like most of us do – with a full face-plant type failure. His first attempted at building an internal combustion engine wouldn’t run, due to a low compression ratio, and too small port sizes. So he did what most of us would do, and tore apart a small gas-power weed-whacker motor to see what he was doing wrong.

The type of engine he’s making is a 2-stroke. That makes the design much simpler as there are no mechanically controlled valves a like 4-stroke motor. The piston (along with the cylinder wall) does double duty by also directing the intake and exhaust gasses – along with a simple flap-type check valve.

For now, the ignition system is run off of mains power, but he has plans to change that – creating a self contained engine. We’re amazed that the entire build is made with such simple tools. Even the the piston is cast out of “JB Weld” epoxy putty. After seeing this, we think that the kid who took apart a clock is going to have to up his game a bit.

We’ve included all 6 parts after the break.

Continue reading “Homemade Internal Combustion Engine – Sans Machine Shop” →

Muscle Wire Pen Dances To Duke Nukem

December 22, 2015 by 2 Comments

[serdef] is clearly just having a little bit of fun here. One never needs a whiteboard pen that’s syncronized by MIDI to dance along with the theme from Duke Nukem.

But if you had all of the parts on hand (a highly liquid MIDI-driven relay board that connects straight up to a soundcard, some muscle wire, tape, and a whiteboard pen, naturally) we’re pretty sure that you would. You can watch the dancing pen in a video below the break.

The project is really about documenting the properties of [serdef]’s muscle wire, and he found that it doesn’t really contract enough with a short piece to get the desired effect. So he added more wire. We’ve always meant to get around to playing with muscle wire, and we were surprised by how quickly it reacted to changing the voltage in [serdef]’s second video.

Now the dancing pen isn’t the most sophisticated muscle wire project we’ve ever seen. And that award also doesn’t go to this Nitinol-powered inchworm. Did you know that there’s muscle wire inside Microsoft’s Surface?

Continue reading “Muscle Wire Pen Dances To Duke Nukem” →

Microcontroller Lectures By Bruce Land

December 21, 2015 by 18 Comments

[Bruce Land] is no stranger to Hackaday as you can see from his Hackaday.io profile, if you aren’t familiar with his work [Bruce Land] is a Senior Lecturer at Cornell University. One of the courses he teaches: Digital Systems Design Using Microcontrollers (ECE4760) was recorded in 2012 and again in 2015 and the videos are available on YouTube.

AVR to PIC32

[Bruce Land]s previous set of ECE4760 lectures (2012) used an Atmel ATmega1284 AVR Microcontroller for the laboratory portion of the course. This means the lectures are also based on the AVR and if you haven’t watched them through a few times you should do. The recently updated set of lectures is based on the Microchip PIC32, more specifically the Microstick II.

Open Curriculum

You can follow the ECE4760 rabbit hole as far as you want with all the available content provided by [Bruce Land] on his ECE4760 course webpage. You can watch the ECE4760 lectures on YouTube, try your hand at the homework assignments, and work through the labs at your own pace.

New Lectures = New Shirts

One area that [Bruce Land] is unmatched and arguably uncontested is his shirt collection, we are continuously impressed with these original works and wish they were available for purchase (wink/hint c’mon [Bruce] throw us a bone!). If you don’t know why the rest of us aren’t able to obtain the wonderful shirts [Bruce Land] wears you clearly aren’t subscribed to [Bruce Land]s YouTube channel, you should rectify that wrong and log some ECE4760 lecture hours starting with the video after the break.

Raspberry Pi Laser Beam Profiler

December 21, 2015 by 3 Comments

[Anthony] at UCLA needed to verify the shape of a laser beam. Commercial units for this, as you would expect, are expensive. But a Raspberry Pi with a Pi Noir camera easily handles the task. Not only is the use of the Pi cool but so is the task – they are using lasers to cool molecules to study quantum effects. The Pi camera without the IR filter captures a wide bandwidth making it suitable for use with non-visible lasers. [Anthony] captures the beam along two axes and plots both curves on the LCD touchscreen. That data, based on the pictures, is also available on a host PC. All this in a super compact package with a 7″ touch screen display.

2D crystal of Yb ions.

One reason I find this fascinating is I did something similar 1977 at the University of Rochester Laboratory for Laser Energetics. My project was measuring the energy cross-section of a laser beam. The research goal of the Laboratory was the study of inertial confinement laser fusion. While [Anthony] uses an entire camera my project was limited to a 1 dimensional array of charge coupled devices (CCD). The output went to a Tektronix storage terminal and was printed on thermal paper for reference. He uses Python running on the target system. My work used a Z80 development system the size of a tower PC to write my program in assembly language which was then executed on a single board computer. We’ve come a long way. My code is long gone but you can get [Anthony’s] on GitHub.

Fail Of The Week – Steam Cleaner Fix Goes Bad

December 21, 2015 by 40 Comments

[Sven337] was gifted a steam cleaner, and seemed pretty happy because it helped clean the floor better than a regular mop. Until it fell one day, and promptly stopped working. It would produce steam for a short while and then start spitting out cold water, flooding the floor.

Like any self-respecting hacker, he rolled up his sleeves and set about trying to fix it. The most-likely suspect looked like the thermostat — it would switch off and then wouldn’t switch on again until the water temperature fell way below the target, letting out liquid water instead of steam after the first switching cycle. A replacement thermostat was ordered out via eBay.

Meanwhile, he decided to try out his hypothesis by shorting out the thermostat contacts. That’s when things went south. The heater worked, and got over-heated due to the missing thermostat. The over-temperature fuse in the heater coil blew, so [Sven337] avoided burning down his house. But now, he had to replace the fuse as well as the thermostat.

[Sven337] bundled up all the parts and put them in cold storage. The thermostat arrived after almost 2 months. When it was time to put it all together, a piece of fibreglass tubing that slides over the heater coil was missing. Without the protective sleeve, the heater coil was shorting out with the grounded heater body, blowing out the fuses in his apartment.

That’s when [Sven337] called it a day and threw out the darn steam mop — a few dollars down the drain, a few hours lost, but at least he learnt a few things. Murphy’s Law being what it is, he found the missing insulation sleeve right after he’d thrown it away.