DIY Bimetallic Strip Dings For Teatime

May 10, 2024 by Elliot Williams 6 Comments

Do you like your cup of tea to be cooled down to exactly 54 C, have a love for machining, and possess more than a little bit of a mad inventor bent? If so, then you have a lot in common with [Chronova Engineering]. In this video, we see him making a fully mechanical chime-ringing tea-temperature indicator – something we’d be tempted to do in silicon, but that’s admittedly pedestrian in comparison.

The (long) video starts off with making a DIY bimetallic strip out of titanium and brass, which it pretty fun. After some math, it is tested in a cup of hot water to ballpark the deflection. Fast-forward through twenty minutes of machining, and you get to the reveal: a tippy cup that drops a bearing onto a bell when the deflection backs off enough to indicate that the set temperature has been reached. Rube Goldberg would have been proud.

OK, so this is bonkers enough. But would you believe a bimetallic strip can be used as a voltage regulator? How many other wacky uses for this niche tech do you know?

Thanks [Itay] for the tip!

Much Faster Cold Brew Through Cavitation

May 8, 2024 by Kristina Panos 27 Comments

Some coffee snobs might call this sacrilege. Cold brew is supposed to take a long time — that’s part of how it gets its characteristic smoothness. But a group of engineers from the University of New South Wales (UNSW Sydney) have figured out a way to cut the time down from several hours to a mere three minutes, using ultrasonic waves.

Typically, the cold brew coffee process takes between 12 and 24 hours. Enough time to steep the grounds and extract the flavors without the benefit of hot water. This is how it differs from iced coffee, which is brewed hot and poured over ice.

Interestingly, the UNSW Sydney engineers’ process uses a typical prosumer-grade espresso machine and involves blasting the portafilter with a transducer and a horn. This transforms the coffee basket into a sonoreactor. Sound waves at a frequency of 38.8 kHz are injected at multiple points through the walls, generating acoustic cavitation within. You can read all about it in Ultrasonics Sonochemistry.

That’s not even the most exciting part. The study found that this arrangement is capable of doubling both the extraction yield and caffeine concentration, compared with non-soundblasted samples. The team sent samples of the coffee off to be evaluated on aroma, texture, flavor, and aftertaste. Although the one-minute extraction samples received similar ratings to a 24-hour brew in terms of flavor and aftertaste, they lacked the intensity and dark chocolate aroma of the longer brew. But the three-minute extraction samples scored quite highly in all areas, suggesting that the average cold brew drinker wouldn’t be able to tell the difference.

Would you like to roast your own beans at home? You can use a popcorn popper, but you might get tired of semi-uneven roasts and upgrade to a DIY wobble disk roaster.

Continue reading “Much Faster Cold Brew Through Cavitation” →

A DIY coffee roaster with part callouts.

Follow The Red Ball Wobble Disk Roaster To Coffee Excellence

May 3, 2024 by Kristina Panos 7 Comments

If you’ve never considered roasting your own coffee at home, you may be surprised to learn that it can be done in a few minutes with a regular popcorn popper and not much else. After all, you only really need two things to roast coffee: heat, and constant agitation to distribute that heat evenly. While the popcorn popper provides both, it’s easy to end up with semi-uneven roasts, probably because the beans are mostly just spinning around and not being tossed as well as they could be. Eventually, one might want a more advanced machine, and that’s where something like [Larry Cotton]’s latest wobble disk roaster can step in.

For starters, this machine roasts more beans than the average popcorn popper in a single throw — the maximum is 350g, or just over three-quarters of a full pound, which is way more than the average popcorn machine will hold. It essentially consists of a heat gun pointed upwards at a sieve full of green coffee beans that are being constantly pushed around by a motorized wobbling disk. As the heat blows, the large metal disk does figure eights through the beans, keeping the heat nice and even. So where does the red ball come in? It’s at the bottom, keeping the flying bean skins (chaff) from entering the heat gun’s fan motor.

Toward the end of the short video after the break, you’ll see a diagram showing all the parts of this roaster. If that’s not enough for you, here’s a build guide for a previous wobble disk roaster (PDF) that should be quite helpful in building either version.

If you want to see some of Larry’s previous machines, we’ve got ’em. And then you can let Hackaday Editor-in-Chief [Elliot Williams] tell you all about roasting at home.

Continue reading “Follow The Red Ball Wobble Disk Roaster To Coffee Excellence” →

A Fully Automatic British Breakfast: Ready While You Sleep

March 17, 2024 by Maya Posch 35 Comments

What do you mean, the temporary breadboard setup went into production? (Credit: Gregulations, YouTube) — What do you mean, the temporary breadboard setup went into production? (Credit: [Gregulations], YouTube)

Among all the amazing technologies that were promised to us, there is one that is much more egregious than the lack of flying cars and real hovering hoverboards: the lack of fully automated breakfast-maker machines. Instead we find ourselves handling the same dumb appliances each morning as we make a healthy breakfast that we then have time to wolf down before rushing out of the door to still be a few minutes late for work. When [Greg] researched machines that could automatically prepare breakfast, he came up empty, which led him down the rabbit hole of the Autochef-9000.

Although often featured in movies – ranging from Back to the Future to Wallace and Gromit – the contraptions in those are rarely practical, and real-life attempts often suffer the problem of feature creep as they have to handle too many ingredients and operations. This is where [Greg] found redemption in the simplicity of a proper British breakfast: beans, toast, sausages (sossys), and eggs. Months of CAD, welding, breadboarding, and writing Arduino code later, he made a machine that can open a can of beans, toast bread, boil eggs, fry up sausages, and deposit it all on a plate, all ready for that morning breakfast first thing when you stroll into the kitchen.

Thanks to [htky] for the tip.

Continue reading “A Fully Automatic British Breakfast: Ready While You Sleep” →

Hack Makes Microwave Cookies Fast And Not Terrible

March 11, 2024 by Dan Maloney 35 Comments

Making a chocolate chip cookie is easy. Making a good chocolate chip cookie is a little harder. Making a good chocolate chip cookie quickly is a pretty tall order, but if you cobble together a microwave and a conventional oven, you just might get delicious and fast to get together.

The goal of this Frankenstein-esque project is to build a vending machine that can whip up a fresh-baked chocolate chip cookie on demand and make [Chaz] wealthy beyond his wildest dreams. We’re guessing at that last part; for all we know his goal is world peace through instant cookies. We’re fine with the idea either way, and his previous work on the project resulted in a semi-automatic cookie gun to splooge the dough out in suitable dollops.

The current work is turning those into something edible, for which a microwave seems a logical choice. Experience tells us otherwise, so off to the thrift store went [Chaz], returning with a used air fryer. He ripped the guts out of a small microwave, slapped the magnetron onto the side of the air fryer, and discovered that this was officially A Bad Idea™ via a microwave leakage tester. Round 2 went the other way — adding a conventional heating element to a large microwave. That worked much better, especially after close-up video revealed the dynamics of microwave cookery and the best way to combine the two cooking modalities. The result is a contraption that makes a pretty tasty-looking two-minute cookie. World peace, here we come!

Of course there’s plenty to say about the safety of all this, much of which [Chaz] himself cops to in the video. It’s important to remember that he’s just prototyping here; we’re sure the final machine will be a little more sophisticated than a heat gun duct-taped to the side of a microwave. Those cookies aren’t going to bake themselves, though, so you’ve got to start somewhere.

Continue reading “Hack Makes Microwave Cookies Fast And Not Terrible” →

A white woman with a long ponytail in a green apron looks down at a mannequin head with pasta coming out of its chin. There is an orange pasta gun sticking out of the back of its head and a chef's hat on its head. It looks vaguely like a bust of Ramses.

Goatee Pasta Maker Makes Us Hunger For Hair

March 4, 2024 by Navarre Bartz 9 Comments

Some hacks are pure acts of whimsy, and [Simone Giertz] is back to her roots with this Goatee Pasta Maker.

If violence to mannequin heads is upsetting, the video may be a bit NSFW (to warn you now that you already clicked on it). What started out as a pasta-making version of those Play-Doh hair people quickly morphed into a more scaled-back endeavor with simply extruding pasta through the mannequin’s chin to create pasta hair.

Initial attempts at using a basketball to extrude clay (used as a pasta stand-in) through holes in a mannequin’s head were unsuccessful, so [Giertz] turned to a more conventional pasta gun to handle the pasta extrusion. Since the gun didn’t have the volume necessary to produce a full head of hair, or even a respectable mustache, the next mannequin’s chin was subjected to multiple drill holes for pasta to escape in a hairy tangle.

The results aren’t exactly appetizing, but it definitely does make edible pasta. If you’re looking for more pasta hacks, how about ramen in an edible package, flat pack pasta, or Barilla’s Open Source pasta tool?

Continue reading “Goatee Pasta Maker Makes Us Hunger For Hair” →

3D Printed Eel Could Cost Less At Scale

January 6, 2024 by Kristina Panos 38 Comments

Be it a matter of cost, principle, or just plain being landlocked, the idea of 3D printed vegan eel over the real deal is quite an attractive development. An Israeli company called Steakholder Foods has introduced this very thing — something they claim is the world’s first plant-based, printed eel.

One thing to note about eel is that they are quite intricately textured, a problem which seems tailored for 3D printing. The company say they achieve similarity through precise layering and “a unique combination of materials”, which are proprietary. Although the current product is based solely on plant materials, the plan is to incorporate eel cells in the future. Right now, the company is looking to collaborate by providing printers and ink so that participants can create short-term revenue.

While it’s unclear whether the eel is printed and then cooked, or print-cooked like this chicken, it sure looks tasty. Would you eat printed food? Have you done so already? Let us know in the comments.