Reflowduino: Put That Toaster Oven To Good Use

There are few scenes in life more moving than the moment the solder paste melts as the component slides smoothly into place. We’re willing to bet the only reason you don’t have a reflow oven is the cost. Why wouldn’t you want one? Fortunately, the vastly cheaper DIY route has become a whole lot easier since the birth of the Reflowduino – an open source controller for reflow ovens.

This Hackaday Prize entry by [Timothy Woo] provides a super quick way to create your own reflow setup, using any cheap means of heating you have lying around. [Tim] uses a toaster oven he paid $21 for, but anything with a suitable thermal mass will do. The hardware of the Reflowduino is all open source and has been very well documented – both on the main page and over on the project’s GitHub.

The board itself is built around the ATMega32u4 and sports an integrated MAX31855 thermocouple interface (for the all-important PID control), LiPo battery charging, a buzzer for alerting you when input is needed, and Bluetooth. Why Bluetooth? An Android app has been developed for easy control of the Reflowduino, and will even graph the temperature profile.

When it comes to controlling the toaster oven/miscellaneous heat source, a “sidekick” board is available, with a solid state relay hooked up to a mains plug. This makes it a breeze to setup any mains appliance for Arduino control.

We actually covered the Reflowduino last year, but since then [Tim] has also created the Reflowduino32 – a backpack for the DOIT ESP32 dev board. There’s also an Indiegogo campaign now, and some new software as well.

If a toaster oven still doesn’t feel hacky enough for you, we’ve got reflowing with hair straighteners, and even car headlights.

Breadboarding: Git for A/B Testing Actual Bread

We will be the first to admit, we like to use Git for a lot of things that are probably off the beaten path. But now thanks to [hendricius] you can find out how to make your own bread on GitHub. Let’s get one thing straight. This isn’t the breadmaker fad from a while back, although we are surprised we don’t see more hacked together breadmakers with Internet connectivity. This is old-fashioned bread baking with a bowl, some ingredients, and an oven or another heat source.

You might think this is just using Git as a repository for recipes, but it is more than that. According to [hendricius]:

Learn how to master the art of baking the programmer way. If you love programming, you will also enjoy breaking some bread. A/B test, iterate and ultimately become a self-taught baker. This repository is dedicated to becoming your bread manifesto with useful tricks and hacks. Furthermore, the goal is to illustrate how easy making bread is and that you can get started today without expensive tools.

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Delicious Optics, A Chocolate Diffraction Grating

Diffraction gratings are curious things. Score a series of equally spaced tiny lines in a surface, and it will cause reflected or transmitted light to bend and separate into its component wavelengths. This ability gives them all manner of important applications in the field of optics, but they’re also fun to play with. [Tech Ingredients] has done the hard work to find out how to make them out of candy!

The video starts with a basic discussion on the principles of diffraction gratings. The basis of the work is a commonly available diffraction grating, readily available online. It’s a plastic sheet with thousands of microscopic ridges scored into the surface. The overarching method to create a candy version of this is simple — coat the ridged surface in liquid chocolate or sugar syrup, to transfer the impression on to the candy surface when it solidifies. However, the video goes further, explaining every step required to produce a successful end result. The attention to detail is on the level of an industrial process, and shows a mastery of both science and candy processing techniques. If you’ve ever wondered how to properly crystallize chocolate, this video has the knowledge you need.

It’s not often we see candy optics, but we like it — and if you fail, you can always eat your mistakes and try again. If you’re wondering what you can do with a diffraction grating, check out this DIY USB spectrometer.

Automated Syrup System is Sweet Sweet Madness

Here at Hackaday we are big fans of the TV show, “How It’s Made”. It’s not much of a stretch to assume that, as somebody who is currently reading this site, you’ve probably seen it yourself. While it’s always interesting to see the behind the scenes process to create everyday products, one of the most fascinating aspects of the show is seeing how hard it is to make things. Seriously, it’s enough to make you wonder how companies are turning a profit on some of these products when you see just how much technology and manual work is required to produce them.

That’s precisely the feeling we got when browsing through this absolutely incredible overview of how [HDC3] makes his maple syrup. If that’s not a sentence you ever thought you’d see on Hackaday, you aren’t alone. But this isn’t a rusty old pail hanging off of a tap, this is a high-tech automated system that’s capable of draining 100’s of gallons of sap from whole groves of trees. We’ll never look at a bottle of syrup in the store the same away again.

It all starts with hundreds of tiny taps that are drilled into the trees and connected to a network of flexible hoses. The plumbing arrangement is so complex that, in certain, areas high tension support wires are necessary to hold up the weight of the hoses and their sweet contents. The main hose leads to an Arduino-powered collection station which maintains a 100 kPa (29 inHg) vacuum throughout the entire system.

The sap is temporarily held in a 250 gallon container, but at this point it’s still just that: sap. It needs to be refined into something suitable for putting on your pancakes. The first step of that process utilizes a reverse osmosis filtration system to pull the water out of the sap and increase its sugar concentration. [HDC3] says the filtration system is built from eBay scores and parts from the home improvement store, and it certainly looks the part of something that would be under a kitchen sink. This system is able to increase the sugar concentration of the sap from around 2% as it comes out of the trees to 8%. But it’s still a far way off from being ready to use.

Interestingly enough, the last steps of the process are about as old-school as they come. The semi-concentrated sap is placed in a long low metal pan, and heated over a wood fire to drive off more of the water. This process continues until the sap is roughly 60% sugar, at which point it is filtered and moved into the house to finish boiling on the stove.

All told, the syrup is boiled for eight hours to bring its sugar content up to 66%. Even with the improvements [HDC3] has made to the system, he reveals that all this hard work only results in slightly more than a half-gallon of final syrup. Talk about dedication.

It probably comes as no surprise that this is the first time Hackaday has ever run a story about producing maple syrup. However we’ve seen a number of automated beer brewing systems that seem to have been tackled with similar zeal. There’s probably a conclusion to be drawn there about the average hacker’s diet, but that’s a bit outside our wheelhouse.

[via /r/DIY]

Printed Adapter Teaches an Old Ninja New Tricks

Do you like change for the sake of change? Are you incapable of leaving something in a known and working state, and would rather fiddle endlessly with it? Are you unconcerned about introducing arbitrary compatibility issues into your seemingly straight-forward product line? If you answered “Yes” to any of those questions, have we got the job for you! You can become a product engineer, and spend your days confounding customers who labor under the unrealistic expectation that a product they purchased in the past would still work with seemingly identical accessories offered by the same company a few years down the line. If interested please report to the recruitment office, located in the darkest depths of Hell.

A 2D representation of the adapter in Fusion 360

Until the world is rid of arbitrary limitations in consumer hardware, we’ll keep chronicling the exploits of brave warriors like [Alex Whittemore], who take such matters into their own hands. When he realized that the blades for his newer model Ninja food processor didn’t work on the older motor simply because the spline was a different size, he set out to design and print an adapter to re-unify the Ninja product line.

[Alex] tried taking a picture of the spline and importing that into Fusion 360, but in the end found it was more trouble than it was worth. As is the case with many printed part success stories, he ended up spending some intimate time with a pair of calipers to get the design where he wanted it. Once broken down into its core geometric components (a group of cylinders interconnected with arches), it didn’t take as long as he feared. In the end the adapter may come out a bit tighter than necessary depending on the printer, but that’s nothing a few swift whacks with a rubber mallet can’t fix.

This project is a perfect example of a hack that would be much harder (but not impossible) without having access to a 3D printer. While you could create this spline adapter by other means, we certainly wouldn’t want to. Especially if you’re trying to make more than one of them. Small runs of highly-specialized objects is where 3D printing really shines.

This is an entry in Hackaday’s

Repairs You Can Print contest

The twenty best projects will receive $100 in Tindie credit, and for the best projects by a Student or Organization, we’ve got two brand-new Prusa i3 MK3 printers. With a printer like that, you’ll be breaking stuff around the house just to have an excuse to make replacement parts.


Build an Excellent Coffee Roaster With a Satisfyingly Low Price Tag

There’s a lot of mysticism around coffee roasting, but in the end it couldn’t be simpler. Take a bunch of beans, heat them up evenly, and stop before they get burned. The rest is details.

And the same goes for coffee roasters. The most primitive roasting technique involves stirring the beans in a pan or wok to keep them from scorching on the bottom. This works great, but it doesn’t scale. Industrial drum roasters heat a rotating drum with ridges on the inside like a cement mixer to keep the beans in constant motion while they pass over a gas fire. Fluidized-bed roasters use a strong stream of heated air to whirl the beans around while roasting them evenly. But the bottom line is that a coffee roaster needs to agitate the beans over a controllable heat source so that they roast as evenly as possible.

My DIY coffee roaster gave up the ghost a few days ago and I immediately ordered the essential replacement part, a hot air popcorn popper, to avert a true crisis: no coffee! While I was rebuilding, I thought I’d take some pictures and share what I know about the subject. So if you’re interested in roasting coffee, making a popcorn popper into a roaster, or even just taking an inside look at a thoroughly value-engineered kitchen machine, read on!

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BeefBot: Your Robotic Grill Master

Have you ever been too busy to attend to the proper cooking of a steak? Well, lament no more, and warn your cardiologist. A trio of students from Cornell University have designed and built the steak-grilling BeefBot to make your delicious dinner dreams a reality.

[Jonah Mittler], [Kelsey Nedd], and [Martin Herrera] — electrical and computer engineering students — are the ones you should thank for this robot-chef. It works as follows: after skewering the steak onto the robot’s prongs, BeefBot lowers it onto the grill and monitors the internal temperature in a way that only the well-seasoned grillmaster can replicate. Once a set temperature is reached, the steak is flipped — sorry, no crosshatch grillmarks here — and cooked until a desired doneness. A small screen displays the temperature if you want to babysit BeefBot — some manual adjustment may be needed after the steak flip to ensure it is cooking evenly — but it is otherwise a hands-off affair. If you don’t mind salivating over your screen, check out the project demonstration after the break.

At first glance you might think this a YouTube stunt, but this is real science. The writeup is exquisite, from the design and fabrication, to the math behind temperature calibration and regulation. Kudos to the hungry Cornell students who slaved over a hot griddle bringing this one to life!

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