A month ago, Hackaday landed at the NYC TechCrunch Disrupt, a bastion of people up all night on MacBooks and immense amounts of caffeine and vitamin B12. For 20 hours, everyone was typing away trying to build the next great service that would be bought by Google or Amazon or Facebook. Tucked away in one small corner of the room was the Hackaday crew, giving out dev boards, components, and advice to the few dozen hardware hackers at Disrupt. [David], one of these Hackaday enthusiasts won the Twilio Sponsorship Prize at Disrupt, and now it’s a Hackaday Prize entry.
[David]’s dad has a little bit of paranoia of accidentally leaving the stove on. This usually manifests itself a few minutes after leaving the house, which means turning the car around just to make sure the stove was off. At the TechCrunch hackathon, [David] built a small IoT device to automatically read the temperature of the stove, send that off to the Internet, and finally as an SMS via Twilio.
The hardware [David] is using is extremely minimal – a thermopile, a gas sensor, a WiFi module, and a microcontroller. There’s a lot of iterations in this project, with [David] looking at everything from TI MSP430s to Teensys to Arduinos to ESP8266 modules. Still, rough prototype thrown together in 20 hours is all you need to win the Twilio prize at Disrupt, and that’s more than enough for a very good Hackaday Prize entry.
[Ken] found an interesting use for his sous vide cooker. He’s been using it to help him with his home brewing. It’s unlikely that the manufacturer ever intended it to be used in this manner, but as hackers we don’t really care about warranties.
Beer brewing is as much of an art as it is a science. There are a lot of variables that go into the process, and tweaking any one of them can result in your beer tasting different. There is one process during brewing that is called mashing. Mashing is when you soak malted grains in hot water to pull out the sugar. The amount of sugar that gets extracted is very dependent on how long the grains are soaked, and the temperature of the water. If you want your beer to taste a certain way, then you want to ensure that the water stays at constant, repeatable temperature.
As a home brewer, [Ken] has been using his stove top to heat the water. This gets the water warm, but in order to keep the temperature consistent, he has to constantly monitor the temperature and adjust the knob accordingly. Who wants to sit around and do that all day? He needed something to control the temperature automatically. Enter the sous vide cooker.
Sous vide is a method of cooking in which food is placed into an airtight bag and then submerged in a water bath with very strict temperature control. The process takes a long time to cook the food, but the result is supposed to be meat that is cooked perfectly even while also retaining all of the moisture and juices. [Ken] figured he might be able to use a sous vide cooker to control the temperature of the mash instead of a water bath.
His experiment worked wonderfully. He used the stove top to help get the mash up to the close temperature, then the sous vide cooker was used to fine tune things from there. [Ken] says he was able to achieve 75% efficiency with his mash, which is exactly what he was going for. Continue reading “Brewing Beer with a Sous Vide Cooker”
This little piggy probably should have gone to the market. Instead, its become an extremely decorative, and cute, wood burning stove!
After being inspired by a similar Instructable that guides you through the creation of a wood stove using an expired gas cylinder, [Ruudvande] had to try it himself. The problem was — he didn’t have a gas tank. Luckily for him, he found someone who did, but as it turned out, they wanted to turn it into a barbecue! So, slightly sidetracked, he built them a barbecue using the center of the cylinder, and got to keep the ends and enough steel to make Mr. Piggy himself.
Almost the entire wood burning stove is made of scrap bits and pieces of steel, and various pieces of mounting hardware. Armed with just a MIG welder, [Ruudvande] welded it together all by hand, and we think it turned out great! He’s not quite happy with it yet though and plans to upgrade the chimney, put a larger grill inside, paint it, and even add a glass window to the door.
[Tim] is a homebrewer. Temperature profiling during the mashing process is apparently even more critical than the temperature curve of a solder reflow oven. His stove just wasn’t giving him the level of control he needed, so [Tim] added a PID temperature controller to his stove. Electric stoves generally use an “infinite switch” to control their burners. Infinite switches are little more than a resistor and a bimetallic strip in a single package. Not very good for accurate temperature control. The tricky part of this hack was to make it reversible and to have little visual impact on the stove. A stove top with wires hanging out would not only be dangerous electrically, it would also create a hazardous situation between [Tim] and his wife.
[Tim’s] brewpot only fit on the stove’s largest burner, so that was the only one that needed PID control. To keep things simple, he kept the commercial PID controller outside the stove’s enclosure. Inside the stove, [Tim] added a solid state relay. The relay is mounted to a metal plate, which screws to the back of the stove. The relay control lines run to an audio jack on the left side of the stove. Everything can be bypassed with a switch hidden on the right side of the stove. In normal operation, the switch is in “bypass” mode, and the stove works as it always has. When mashing time comes along, [Tim] flips the switch and plugs the jack into his PID controller. The temperature sensor goes into the brewpot itself, so no stove modification was needed there.
The end result is a very clean install that both [Tim] and his wife can enjoy. Save a few bottles for us, [Tim]!
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.
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!
[Rxdtxd] has tried his hand at roasting coffee beans in a frying pan. It works but he can only roast small batches at once. What he really needed was a large-scale roaster that would have no problem with a few pounds of the green beans all at once. He ended up building this large-scale coffee roaster out of junk parts.
The vessel which holds the beans is the drum from a top-loading washing machine. It was headed for the junk pile, but the fully-enclosed drum is perfect for this purpose. After acquiring it [Rxdtxd] set out welding a frame that would hold either side by the pivot points. He used a geared motor to automate the process. The output shaft on the gear box is meant to drive a chain, but he just welded some pieces onto the gear to use as a coupling.
In the picture above he’s giving the roaster a thorough testing with about ten pounds of beans. A portable gas stove placed below the rotating drum supplies the heat. After the beans have reached the desired darkness he pours them out into a large skillet to cool. Take a peek at the roasting action in the clip after the break.
Continue reading “Building a coffee roaster from junk”