Generating electricity from alcohol


Here’s a thermoelectric generator which [x2Jiggy] built. The concept uses heat from a flame, biased against cooler temperatures produced by that huge heat sink making up the top portion of the build to produce electricity via the Peltier effect.

The build is passively cooled, using a sync assembly that takes advantage of heat pipes to help increase the heat dissipation. A nearly flat heat sink makes up the mounting surface for the hot side, which faces down toward a flame driving the generator. [x2Jiggy] started the project by using a can, wick, and olive oil as the heat source. He managed to get about 2V out of the system with this method. What you see here is the second version. It swaps out the olive oil lamp for an alcohol stove. The cans with holes punched in them act as a wind screen while also providing a stable base. This rendition produces about 3V, but it doesn’t sound like there are any precise measurements of what it can do under load.

Robot bartender mixes a mean drink

Back in 2002, [Dave] came across a discarded PUMA robotic arm and quickly set his sights on turning it into a bartender to serve drinks at his parties. Unfortunately, the arm was far from operational and being an engineer at his day job meant that working on this project was the last thing he wanted to do when he came home. So, progress trickled along slowly for years. He eventually announced a public deadline to spur him to action, and this years Pi(e) party saw the official debut of  ‘Sir-Mix-a-Bot’ – the robot bartender.

With the exception of having to build a new hand for it, mechanically, the arm was still in good condition when [Dave] found it. The electronics were another story however. Using some off the shelf components and his own know-how, [Dave] had to custom build all the controls. The software was written from scratch as well. (He lucked out and had help from his brother who was taking a Ph.D. program in robotics at the time).

As if the robotics aspect of the project wasn’t enough, [Dave] even created a beautiful custom table that both houses and displays his masterpiece. The quality of craftsmanship on his table alone is worth the time to check this out – there’s a short video after the break.

[Thanks Dave]

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Gas sensor suite built with Gadgeteer modules


[Blake] just finished a gas sensor suite built from Gadgeteer parts. The three sensors are the cylindrical towers along the left hand side of the assembly. The one at the top (with the orange ring) is an alcohol sensor. The middle one senses ammonia and the lower sensor measures air quality. Also rolled into the mix are temperature and humidity sensors.

You can collect a lot of data with this type of setup. To keep it organized [Blake] used the ThingSpeak interface. Using the NIC in the upper right he uploads the measurements for real-time graphing. The setup is explained in detail in the video after the break, including a test with some cleaning ammonia.

We haven’t tried out the Gadgeteer system for ourselves yet. But you’ve got to admit that the ribbon cable connector system the family of parts uses really helps to keep a rather complicated setup like this one nice and tidy.

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LED ice cubes prevent alcohol induced blackouts


On November 23rd last year, [Dhairya] attended a little shindig at MIT. Three drinks into the night, he blacked out and woke up in the hospital the next day. It was an alcohol-induced blackout, and like all parties at MIT, there’s an ingenious solution to [Dhairya]’s problem.

[Dhairya] came up with an alcohol-aware ice cube made of a coin cell battery, an ATtiny microcontroller, and an IR transceiver are molded into an edible gelatin ice cube. The microcontroller counts the number of sips per drink, and after one glass of adult beverage changes the color of the flashing LED from green to yellow. After two drinks the LED changes from yellow to red, signaling [Dhairya] to slow down.

If [Dhairya] feels the night is too young and keeps on drinking, the IR transmitter signals to his cell phone to send a text to a friend telling them to go take [Dhairya] home.

Less than three weeks after waking up in the hospital, [Dhairya] tested out his glowing ice cubes at another party. Everything performed wonderfully, even if he admits his creation is a little crude. A neat piece of work, and we can’t wait to see an update to this project.

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Red-bullet: cooking stove from cans, fueled by gas additive

A couple of beverage containers and a little bit of fuel additive bring together this aluminum can stove project. When lit it shoots flames out each of those holes around the top to heat the vessel resting upon it. [Peter Geiger] calls it the Red-Bullet because one of the stove pieces started as a Red Bull can and the other piece was a Coors (aka silver bullet).

This is basically an alcohol stove. We remember seeing a very well designed version of the penny stove several years back. This is different as it uses a side burner so the stove itself functions as the kettle stand. [Peter] started by cutting the Red Bull can just a bit taller than the final height. He then inserted the top portion of one of those aluminum beer cans that are shaped like glass bottles. The neck was lopped off and inverted. It is joined with the other can base using JB weld and by rolling the aluminum in on itself. After that has dried the holes are added and it’s filled with HEET from a yellow bottle. This gasoline additive is meant to sequester water and keep your gas line from freezing. The yellow bottle is mainly alcohol, the red is methanol so make sure you use the right one!

An actively cooled cloud chamber

This cloud chamber is designed to keep the environment friendly for observing ionizing radiation. The group over at the LVL1 Hackerspace put it together and posted everything you need to know to try it out for yourself.

A cloud chamber uses a layer of alcohol vapor as a visual indicator of ionizing particles. As the name suggests, this vapor looks much like a cloud and the particles rip though it like tiny bullets. You can’t see the particles, but the turbulence they cause in the vapor is quite visible. Check out the .GIF example linked at the very bottom of their writeup.

The chamber itself uses a Peltier cooler and a CPU heat sink. The mounting and insulation system is brilliant and we think it’s the most reliable way we’ve seen of putting one of these together. Just remember that you need a radioactive source inside the chamber or you’ll be waiting a long time to see any particles. They’re using a test source here, but we saw a cloud chamber at our own local Hackerspace that used thoriated tungsten welding rods which are slightly radioactive.

[Thanks JAC_101]

DIY flux comes straight from the tree

[Tom] needed more solder flux and instead of buying it he thought he’d try making his own. The thing is, he didn’t have any rosin on hand. But knowing its source let him acquire it for free. He took a sample of tree sap and turned it into his own solder flux.

We’ve seen a few different DIY flux recipes this year. The most recent guide suggests sourcing rosin from the hardware store because of the quality, or if that fails you’ll find some at the music store. [Tom] was lucky enough to find a large dollop leaking from a pine tree in his neighborhood. He let it sit overnight in a container along with some isopropyl alcohol. In the morning the sap had fully dissolved, so he ran it through a coffee filter to get rid of any debris. He keeps it in a small jar, applying it to his projects using cotton swabs. You can see his short soldering demo after the break.

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