[Patrick Herd] was in Sweden recently and decided to help out a team of high school students in the International Young Physicist Tournament — The challenge? Chocolate Hysteresis.
Chocolate what? When chocolate melts, it doesn’t actually re-solidify at it’s melting point — in fact, it’s quite below that. The challenge here is figuring out a scientific way of measuring the time (and temperature) it takes to return to a solid state. This in itself is kind of tricky considering you have to accurately measure the temperature and be able to empirically tell if its solid or liquid.
The first scientific apparatus they came up with was the Chocolate Rig V1 – a very simple peltier heated and cooled calorimeter. They used an Arduino to control the temperature and a motor shield to power the peltier plate. It kind of worked but they discovered it was difficult to assess the physical state of the chocolate. This is when [Patrick] started doing some research and discovered rotary viscometry.
Continue reading “Melting Chocolate – FOR SCIENCE!”
It’s summer. It’s hot. After [Alex Shure] tried his hand at making his own ice cream, he knew he had to take it a step farther. Introducing icenBerg. He’s not just in the ice cream business. He’s building an empire.
Using various odds and ends from the workshop, an old mini fridge donated to him by friends, and a lathe, [Alex] built the first iteration of icenBerg. It features a fancy machined paddle inside the insulated housing, which can be driven by a power drill — or at least that was the plan…
The salvaged compressor system from the mini fridge provides the cooling for the machine. In his first attempt, he found a power drill wasn’t quite strong enough — so he ended up chucking the entire thing into his lathe for unbeatable ice cream mixing. The flavor of choice was apple banana coconut sorbet with chocolate oak cookie chunks and roasted soybeans (say that 10 times fast!).
The machine is far from complete, but as a proof of
concept deliciousness it has spurred him to make it even better. He plans on making it a standalone unit using a windshield wiper motor, a PWM circuit with a microcontroller, and even hopes to correlate motor current to ice cream consistency.
If you have not heard of the sous-vide method of cooking you are not alone. This method uses a low temperature water bath to cook food in airtight plastic bags. Because the temperatures are much lower than normal the cooking time must be much longer and the actual temperature is very critical. The advantage is that the food is heated evenly without overcooking the outside. Since the food is bagged, it also retains moisture.
[Brian] put together a sous-vide control system to automatically maintain the correct temperature of a rice cooker. A temperature control unit was sourced on eBay for about $15. This is not a bad deal considering it has an LED display, control buttons, built-in relay and thermometer input. The control unit is mounted inside a project box with a few other components. The 120 volt AC line comes into the box where the neutral and ground are connected to the control unit and a standard outlet. The hot wire is connected directly to the control unit which determines if the hot wire is or isn’t connected to the outlet by using its built-in relay.
Continue reading “Precision Temperatures for Cooking or Whatever”
Oh for the day when we can stop repeatedly looking up our favorite drink recipes on Wikipedia. Those may be just around the corner and you’ll have your choice of single-click delivery or toiling away in the workshop for a scratch build. That’s because Barobot is satisfying both the consumer market and our thirst for open hardware goodness. They’re running a Kickstarter but to our delight, the software and mechanical design files are already posted. Before you dig into the design files there’s a really good look at the constituent parts in the assembly manual (PDF) — that’s a lot of pieces! — and a tiny bit on the tech-stuff page.
This remind us of the Drinkmo we saw earlier in the year. That one cames complete with the high-pitched whine of stepper motors. We didn’t get to hear Barobot’s ambient noise in the promo vid after the break. But one place this desing really shines is a swiveling caddy that allows for a double-row of bottles in a similar footprint. One thing we’d be interesting in finding out is the cleaning procedure. If anyone know what goes into cleaning something like this let us know in the comments.
Continue reading “Barobot Serves Cocktails While Using Open Design the Right Way”
Homemade reflow ovens are a great inexpensive way to quickly solder multiple prototypes at once. [Andy] may just have built one of the best ones we’ve featured so far on Hackaday. For his project a £25 1300W 12litre halogen oven was chosen because of its low cost and fast heating time, the latter being required to follow typical reflow profile ramp-up stages.
To control the AC power [Andy] first bought a chinese Fotek Solid State Relay (SSR) on ebay, which was quickly replaced by an american one after reading concerning reports on the internet. He then made the same ‘mistake’ by buying the typical MAX6675 thermocouple-to-digital converter from the same website, as he spent much time understanding why the measurements were wrong when the IC was just defective. His final build is based around a 640×360 TFT LCD that he previously reverse engineered, the cortex-M0 STM32F051C8T7, a SPI flash, some power regulators and buttons. The firmware was written in C++ and we’ll let our readers visit [Andy]’s page to see how well his oven performs.
We’ve seen BarBots that will automagically pour you a drink, but how about one with RFID? How about one with Facebook integration, so your friends know how much of a lush you are? Wait. Facebook already tells them that. Huh.
[Andy] and [Daniel]’s latest build follows on the heels of a lot of similar cocktail bots; an Arduino controls a few solenoid valves connected to a CO2 supply and a few bottles of liquor and mixers that allow drinks to be dispensed at the push of the button. Where this project gets interesting is its use of RFID and Facebook.
The user interface was coded for Windows 7, with an RFID tag (ostensibly issued to each guest) allowing a unique login that checks an SQL server to see what privileges the user has. The app pulls the user’s Facebook profile photo down and displays it in the corner of the screen, and with the server keeping track of how many drinks (and of what kind) they had, with the right permissions it should be possible to post that info to their wall. Because we all know what you did last night, even if you don’t.
If you have trouble waking up in the morning then maybe this alarm clock is for you. A bacon-aroma-releasing alarm clock!
Fueled by her love of bacon, Instructable’s user [llopez2005] decided she wanted to try making an alarm clock that would actually get her out of bed, hungry, and ready for bacon. Instead of trying to design a clock that would actually cook bacon — which might be a bit dangerous — she’s found an extract of bacon aroma which she could slowly release instead.
The clock makes use of an Arduino Uno with a RTC shield as well as a LED array for the clock’s display. The “bacon” is actually made out of bake-able clay, which sits on top of unscented wax, infused with the bacon aroma oil. The bacon and “bacon grease” sit in a baby frying pan over top of a small heater element designed for warming candles. Before the alarm goes off, a SSR turns on the element which slowly melts some of the wax, releasing its ever so delicious scent.
What we really like about the clock is the level of detail she put into its appearance. The base is designed after a small wood burning stove they have in the house, and she’s even made a Plexiglas display case for the frying pan — with holes to let the aroma out though of course!