Morbid Battery Uses Blood Electrolyte

March 19, 2017 by 22 Comments

Building a battery out of common household products is actually pretty simple. All that is required is two dissimilar metals and some sort of electrolyte to facility the transfer of charge. A popular grade school science experiment demonstrates this fairly well by using copper and zinc plates set inside a potato or a lemon. Almost anything can be used as the charge transfer medium, as [dmitry] demonstrates by creating a rather macabre battery using his own blood.

The battery was part of an art and science exhibition but it probably wouldn’t be sustainable on a large scale, as it took [dmitry] around 18 months to bank enough blood to make a useful battery. Blood contains a lot of electrolytes that make it perfect for this application though, and with the addition of the copper anode and aluminum cathode [dmitry] can power a small speaker which plays a sound-generating algorithm that frankly adds a very surreal element to the art installation.

While we can’t recommend that you try to build one of these batteries on your own without proper medical supervision, the video of the art piece is worth checking out. We’ve seen a few other hacks that involve blood, but usually they are attempting to use it for its intended purpose rather than as an alternative energy source.

You Will Want To Build This Canoe

March 19, 2017 by 22 Comments

There is something about a wooden boat that should be facsinating to most makers, the craftsmanship and level of work that goes into creating a sea-, lake-, or river-worthy craft with smooth lines, from little more than thin pieces of wood. Master boatbuilders have apprenticeships that last years, and spend entire careers refining their art.

[Adam], also known as [A Guy Doing Stuff], is not a master boatbuilder. In his words, he’s just a guy with some basic woodworking knowledge, who builds canoes from cedar strips. But you wouldn’t know that he has no training as a boatbuilder from looking at his work, which you can do because he’s posted some beauthiful videos.

We see the creation of a skeleton to produce the basic shape of the boat, followed by the creation of prow and stern. Then there is a painstaking application of carefully shaped cedar strips to make the hull, and a single layer of glass fibre on either side. With the gel coat applied though you wouldn’t know the fibre was there. Finally we have the creation of the seats and interior fittings, followed by the canoe being paddled across a lake.

Few of us may ever make a canoe. But if we did, we’d want it to be one like this one.

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Micro Wind Turbine For Hikers

March 18, 2017 by 77 Comments

[Nils Ferber] is a product designer from Germany. His portfolio includes everything from kitchen appliances to backpacks. One project, though, has generated a bit of attention. It’s a micro wind turbine aimed at long distance hikers.

Even on the trail, electronics have become a necessity. From GPS units to satellite phones, to ebook readers. Carrying extra batteries means more pack weight, so many hikers utilize solar panels. The problem is that when the sun is up, hikers are on the move – not very conducive to deploying a solar array. The Wind, however, blows all through the night.

[Nils] used carbon fiber tube, ripstop nylon, and techniques more often found in kite building to create his device. The turbine starts as a small cylindrical pack. Deploying it takes only a few minutes of opening panels and rigging guy wires. Once deployed, the turbine is ready to go.

While this is just a prototype, [Nils] claims it generates 5 Watts at a wind speed of 18 km/h, which can be used to charge internal batteries, or sent directly to any USB device. That seems a bit low for such a stiff wind, but again, this is just a prototype. Could you do better? Tell us in the comments! If you’re looking for a DIY wind generator on a slightly larger scale, you could just build one from bike parts.

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Flexible Quadcopter Is Nearly Indestructible

March 18, 2017 by 20 Comments

We’ve all crashed quadcopters. It’s almost inevitable. Everything is going along fine and dandy ’till mother nature opens her big mouth a blows a nasty gust of wind right at you, pushing your quad into the side of a wall. A wall that happens to be composed of a material that is quite a bit harder than your quadcopter. “What if…” you ask yourself while picking up the pieces of you shiny new quad off the ground… “they made these things out of flexible material?”

Well, it would appear someone has done just that. The crash resistant quadcopter is composed of a flexible frame (obviously) which is held rigid with magnets. So the frame works just like the frame of your average quad. Until you crash it, of course. Then it becomes flexible.

The idea came from the wing of a wasp, which you can apparently crumple without damaging it. Be sure to check out the video below of the drone showing off its flexible frame, and let us know if you’ve seen any other types of flexible frame drones in the wild.

Thanks to [JDHE] for the tip!

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Dumpster Dive Speaker Results In Tube Amplifier

March 18, 2017 by 14 Comments

[Michael Wiebusch] found the leftovers of a wrecked vintage tube radio in a pile of electronics junk. Unfortunately, he could not recover any vacuum tubes in it. And to his dismay, it didn’t even have the output transformer, which he figured would have been useful in a guitar amplifier project. The output transformer is not easy to come by nowadays, so he was hoping to at least score that item for his future build. All he could dig out from his dumpster find was a pair of speakers and he ended up building nice Output-Transformer-Less Tube Guitar Amplifier around them.

Valve output stages are generally high-impedance which means they cannot be directly interfaced to low impedance speakers. An impedance matching output transformer is thus used to interface the two. Back in the day when valves were still the mainstay of audio electronics, many cheap amplifier designs would skimp on the output transformer to save cost, and instead use high impedance speakers connected directly to the amplifier output.

[Michael] found a nice reference design of an OTL amplifier for a 620 ohm single speaker. He decided to use the same design but because these speakers were about 300 ohm each, he would have to wire his two speakers in series. At this point, he decided to make his build useful as a proper guitar amplifier by adding a preamplifier stage replicated from another design that he came across. A regular halogen lamp 12V transformer takes care of the heater power supply for all the tubes, and a second, smaller 12V transformer is wired backwards to provide the 300V needed for the plate supply.

The final result is pretty satisfactory, considering that it all started with just a pair of junked speakers. Check out the result in the video after the break.

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Line Follower Has Lots Of Recycled Parts, But Zero Brains

March 18, 2017 by 20 Comments

Line Followers are a tried-and-true type of robot; both hardware and software need to be doing their job in harmony in order to be successful at a clearly defined physical task. But robots don’t always have microcontrollers and software, as [Mati_DIY]’s zero programming analog line follower demonstrates.

For readers used to seeing a Raspberry Pi or Arduino in almost everything, an analog robot whose “programming” exists only as a harmony between its discrete parts can be an eye-opener as well as an accessible project. A video of the robot in action is embedded below.

[Mati_DIY]’s design uses two CNY70 reflective sensors (which are essentially infrared emitter/phototransistor pairs) and an LM358 dual op-amp. Together, the sensors act as two near-sighted eyes. By using the output of each sensor to drive a motor via a transistor, the presence or absence of the black line is directly and immediately reflected by the motion of the attached motor. The more black the sensor sees, the more the motor turns. Electrically, that’s all that happens; but by attaching the right sensor to the left motor and the left sensor to the right motor, you get a robot that always tries to keep the black line centered under the sensors. Playing with the spacing of the motors and sensors further tweaks the performance.

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Hackaday Unconference Begins!

March 18, 2017 by 3 Comments

This afternoon we are hosting the Hackaday Unconference in three locations at once. Hundreds of creative minds are coming together in Chicago, Los Angeles, and San Francisco for an amazing day of shared inspiration.

You can get a little taste of what is happening by following along with the pulse of the events. Each will be doing some Facebook Live streams so look for that and regular posts on Hackaday Facebook. We’ll be regularly Tweeting and posting to Instagram. It would be absolutely fantastic if you would like and share those messages. Check out the Hackaday TweetWall for a collection of all the #HackadayUncon updates.

The goal is to break down barriers for sharing great ideas which will become the inspiration for new projects to come. Today’s overarching theme is “Build Something That Matters. Everyone attending is ready to give an eight-minute talk about something that interests them, without the pressure of a strict talk order or expectations of polished decks and eloquent delivery. As the Unconference progresses, new discussion groups and impromptu talks take bloom as everyone in attendance guides the direction of the day.