Filtering Coffee Through 3D Printed Glass

Typically, when we think of 3D printing, we think of gooey melted plastics or perhaps UV-cured resins. However, there’s a great deal of research going on around printing special impregnated filaments with alternative materials inside. [Ahron Wayne] has been working on these very materials, and decided to make himself a brew with a prototype print.

Tasty, but [Ahron] notes you shouldn’t drink in the lab.
The subject of [Ahron]’s experimentation is a glass-impregnated filament under development by The Virtual Foundry. The filament is full of tiny glass particles, and the idea is that it can be printed like any regular plastic filament. From there, it’s heated in what’s known as a debinding process, which removes the plastic in the print. Then, it’s heated again in a sintering process to bond the remaining glass particles together.

It’s a complex process, and one that leads to some shrinkage in dimensions as well as porosity in the final part. However, where some might see failure, [Ahron] saw opportunity. The porous printed part was used to filter coffee, with the aid of a little vacuum from what sounds like a water venturi.

[Ahron] notes it’s not a particularly efficient way to make coffee but it did work. We’ve seen exciting work with steel-impregnated filaments, too. Video after the break.

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Why Make Coffee When You’re Tired? Let A Robot Do It For You

Like us, [Alberto] doesn’t compromise when it comes to a good cup of coffee. We figure that if he went to an office in the Before Times, he was the type of coworker to bring in their own coffee equipment so as not to suffer the office brew. Or perhaps he volunteered to order the office supplies and therefore got to decide for everyone else. Yep, that’s definitely one way to do it.

But like many of us, he is now operating out of a home office. Even so, he’s got better things to do than stand around pouring the perfect cup of coffee every morning. See, that’s where we differ, [Alberto]. But we do love Cafeino, your automated pour-over machine. It’s so sleek and lovely, and we’re sure it does a much better job than we do by hand — although we enjoy doing the pouring ourselves.

Cafeino is designed to mimic the movements of a trained barista’s hand, because evidently you’re supposed to pour the water in slow, deliberate swirls to evenly cover the grounds. (Our kettle has a chunky spout, so we just sort of wing it.) Cafeino does this by pumping water from an electric kettle and pouring a thin stream of it in circles with the help of two servos.

The three buttons each represent a different recipe setting, which specifies the amount of water, the hand pouring pattern, and the resting times between blooming the grounds and actually pouring the bulk of the water. These recipes are set using the accompanying web app via an ESP32, although the main brain barista is an Arduino Nano. Grab a cup and check out the demo after the break.

Got an old but modern coffee robot lying around? You could turn it into a planter with automated watering.

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Wobble Disk Coffee Roaster Looks Good In Wood

If you love coffee, you probably make it yourself at home most of the time using beans from some hipster coffee shop where the employees have full-sleeve tattoos and strong opinions. Maybe you even buy whole beans and grind them right before you use them. If you want to go all the way, you gotta roast those beans yourself. There are various ways to go about it, like repurposing a hot air corn popper. If you’re [Larry Cotton], you buy heaps of green beans and keep building wobble disk roasters until you’ve achieved DIY perfection.

[Larry]’s latest roaster boasts all-wood construction with no metal brackets or housings in the structural parts. This is good because you’re less likely to burn yourself on anything, and you aren’t sinking heat away from the beans. Nothing should get hot except the sifter, the beans, and the stiff triangle of wire that holds the heat gun nozzle in place. Once the roasting cycle is complete, [Larry] just shakes out the beans onto an adjacent screen that’s situated over a fan so they can cool off.

Unlike some of [Larry]’s previous designs, this one uses an 8-cup flour sifter situated over a heat gun. A battery-powered screwdriver drives the wobbling disk that churns the beans and helps them roast evenly, and a wooden arm holds down the power button. We love the simplicity of this machine, and think wobble disk roasters are mesmerizing to watch. Check out the video after the break to see it in action and learn how to build your own.

There’s more than one way to roast beans, and one of them is even officially sanctioned by Hackaday editor [Elliot Williams].

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Disposable Rocket Stove Keeps You Fueled In The Wild

Don’t know about you, but we can’t start the day without coffee and a shower. If you were to drag us on some overnight trip into the wilderness, we could probably forego the shower for a day, but we will be a grumpy trail mate without some kind coffee, even instant.

Yes, if you were to get us on an overnight outdoor adventure, we would insist on bringing along a couple of these little disposable, self-destructing rocket stoves, if for no other reason than that we can have some coffee without having to forage for a bunch of firewood and build a whole regular-sized campfire. Don’t worry — we’ll share the water because there’s plenty of time built in. Per [smogdog], these Swedish torches will boil water in 20 minutes and burn for 60 — that’s enough time to make a coffee, a bowl of soup, and toast a single marshmallow before the fire consumes the scrap wood.

We love the use of bike chain as a burner to raise up the pot for fire ventilation. But our favorite bit has to be the dual-purpose packaging. It’s nice-looking, it’s informative, and it’s paper, so you can use it as a fire starter. Failing that, [smogdog] has a backup fire starter system — rubbing alcohol in a small spray bottle. Unwrap a protein bar and check out the demo video after the break.

Tired of the same old, boring trail foods? How about flat-pack pasta that morphs into fun shapes when you boil it?

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3D Printing Espresso Parts

Virtually any hobby has an endless series of rabbit holes to fall into, with new details to learn around every corner. This is true for beekeeping, microcontrollers, bicycles, and gardening (just to name a few), but those involved in the intricate world of coffee roasting and brewing turn this detail dial up to the max. There are countless methods of making coffee, all with devout followers and detractors alike, and each with its unique set of equipment. To explore one of those methods and brew a perfect espresso, [Eric] turned to his trusted 3D printer and some compressed gas cylinders.

An espresso machine uses high pressure to force hot water through finely ground coffee. This pressure is often developed with an electric pump, but there are manual espresso machines as well. These require expensive parts which can withstand high forces, so rather than build a heavy-duty machine with levers, [Eric] turned to compressed CO2 to deliver the high pressure needed.

To build the pressure/brew chamber, he 3D printed most of the parts with the exception of the metal basked which holds the coffee. The 3D printed cap needs to withstand around nine atmospheres of pressure so it’s reasonably thick, held down with four large bolts, and holds a small CO2 canister, relief valve, and pressure gauge.

To [Eric]’s fine tastes, the contraption makes an excellent cup of coffee at minimal cost compared to a traditional espresso machine. The expendable CO2 cartridges only add $0.15 to the total cost of the cup and for it’s simplicity and small size this is an excellent trade-off. He plans to improve on the design over time, and we can’t wait to see what he discovers. In the meantime, we’ll focus on making sure that our beans are of the highest quality so they’re ready for that next espresso.

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Coffee Cupping Is A Grind — Spectroscopy Could Brew Better Beans

If you’ve ever bought whole coffee beans, chances are good that there was all kinds of information on the bag that led to your decision, like the origin, the roast type, and the flavor notes. Traditionally, coffee grading — that’s judging the aroma of both dry and wet grounds and slurping the coffee evenly across the tongue to determine the flavor profile — is done by humans in a process called cupping. To call it a process is too clinical — it’s really more like a ceremony performed with the grave sincerity that coffee deserves.

A traditional cupping ceremony. Image via Kaldi’s Coffee

There’s an industry standard coffee flavor wheel, so why not leverage that to make a robot that can remove the human bias and possible error of doing things the traditional way? That’s exactly what Demetria, a Columbian-Israeli company is doing.

They’ve developed an AI platform that can determine bean quality as judged by handheld scanners that were born on Kickstarter. The scanner uses near-infrared to look for biochemical markers in the bean, which it uses to match up with a profile backed by the all-knowing coffee flavor wheel.

Demetria is using SCiO scanners and a custom app to judge beans before they’re even roasted, which greatly speeds up the process but makes us wonder how green bean spectroscopy stacks up against roasted beans as judged by humans. You may remember the SCiO, a pocket-sized, connected spectrometer made by Consumer Physics that finally started delivering the goods a few years after funding. If you got your hands on a SCiO, you might like to know that there’s an open project out there to hack them. Sparkfun did a nice, thorough teardown, and it seems to be a well-engineered piece of hardware.

On the one hand, cupping is a tradition and thus may people feel that robbing coffee of this tradition will rob coffee of its soul. On the other hand, cupping is wasteful, as the coffee must be roasted and ground immediately prior to the ceremony and it requires the availability of Q graders who have been trained in the ways of coffee grading.

Want to know more about coffee production? Might as well learn the Retrotechtacular way.

[Main and thumbnail images via Demetria]

Keep Coffee Warm Through Induction Heating

Transformers have an obvious use for increasing or decreasing the voltage in AC systems, but they have many other esoteric uses as well. Electric motors and generators are functionally similar and can be modeled as if they are transformers, but the truly interesting applications are outside these industrial settings. Wireless charging is essentially an air-core transformer that allows power to flow through otherwise empty space, and induction cooking uses a similar principle to induce current flow in pots and pans. And, in this case, coffee mugs.

[Sajjad]’s project is an effort to keep his coffee warm while it sits on his desk. To build this special transformer he places his mug inside a coil of thick wire which is connected to a square wave generator. A capacitor sits in parallel with the coil of wire which allows the device to achieve resonance at a specific tuned frequency. Once at that frequency, the coil of wire efficiently generates eddy currents in the metal part of the coffee mug and heats the coffee with a minimum of input energy.

While this project doesn’t work for ceramic mugs, [Sajjad] does demonstrate it with a metal spoon in the mug. While it doesn’t heat up to levels high enough to melt solder, it works to keep coffee warm in a pinch if a metal mug isn’t available. He also plans to upgrade it so it takes up slightly less space on his desk. For now, though, it can easily keep his mug of coffee hot while it sits on his test bench.

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