Hackaday Links: May 15, 2022

May 15, 2022 by Dan Maloney 7 Comments

It may be blurry and blotchy, but it’s ours. The first images of the supermassive black hole at the center of the Milky Way galaxy were revealed this week, and they caused quite a stir. You may recall the first images of the supermassive black hole at the center of the M87 galaxy from a couple of years ago: spectacular images that captured exactly what all the theories said a black hole should look like, or more precisely, what the accretion disk and event horizon should look like, since black holes themselves aren’t much to look at. That black hole, dubbed M87*, is over 55 million light-years away, but is so huge and so active that it was relatively easy to image. The black hole at the center of our own galaxy, Sagittarius A*, is comparatively tiny — its event horizon would fit inside the orbit of Mercury — a much closer at only 26,000 light-years or so. But, our black hole is much less active and obscured by dust, so imaging it was far more difficult. It’s a stunning technical achievement, and the images are certainly worth checking out.

Another one from the “Why didn’t I think of that?” files — contactless haptic feedback using the mouth is now a thing. This comes from the Future Interfaces Group at Carnegie-Mellon and is intended to provide an alternative to what ends up being about the only practical haptic device for VR and AR applications — vibrations from off-balance motors. Instead, this uses an array of ultrasonic transducers positioned on a VR visor and directed at the user’s mouth. By properly driving the array, pressure waves can be directed at the lips, teeth, and tongue of the wearer, providing feedback for in-world events. The mock game demonstrated in the video below is a little creepy — not sure how many people enjoyed the feeling of cobwebs brushing against the face or the splatter of spider guts in the mouth. Still, it’s a pretty cool idea, and we’d like to see how far it can go.

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Smokeless Burn Barrel Makes Your Backyard Fire Much Cleaner

October 21, 2021 by Lewin Day 80 Comments

Old 55-gallon drums are often repurposed into fire barrels with the simple addition of a few holes cut into the walls. Generally, they’re fit enough for purpose but can have a very smoky output, particularly when overloaded. However, this design from [Building Stuff Is Fun] combines two drums into one to create a barrel that burns far more efficiently with less smoke! (Video, embedded below.)

Note the vent holes feeding oxygen to the fire just before the barrel outlet.

Through some clever cuts and folding of steel, a single burn barrel is created from the original two that helps eliminate smoke entirely, through two clever design features. First of all, plentiful air is provided to the fire thanks to the intakes at the bottom of the barrel. Secondly, the barrel-in-barrel design, paired with some smart vents, helps provide fresh air to the fire just before it leaves the barrel. This extra oxygen supply helps create secondary combustion at the outlet which burns up all the matter that would normally be passed out as smoke.

The design involves a lot more work than just hacking some holes in an old drum, but the results are undeniably impressive. The output of the smokeless burn barrel looks far hotter and cleaner. We’ve seen similar designs used to supply workshop heat, too. Video after the break.

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Oil Barrel Smoker

December 4, 2017 by James Hobson 23 Comments

What would you do with a pair of oil drums and a craving for delicious food? Like any sane person, redditor [Kilgore_nrw] made the logical choice and built a smoker.

To make the build easier, he picked up a double barrel stove kit which came with a door, hinges, legs and flue connectors. While fixing the legs and mounting the stove door — high enough for a bed of bricks in the fire barrel — went as planned, he had to improvise the installation of the smoke flue. It ended up being the exact same diameter as the flue connectors, but notching it enough to slide into place made a satisfactory seal.

Not liking the look of having the stack at the ‘front’ of the smoker, he mounted it above the flue at the rear and added two sandstone slabs in the smoking chamber to evenly distribute the heat. Finishing touches included heavy duty drawer slides for the cooking rack — ensuring easy access to deliciousness — and painstakingly grinding off the old paint to apply a new heat resistant coating. For any fans out there, the finished pictures are a sight to behold.

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“The Alarm Clock Ate My Duvet Cover, That’s Why I’m Late!”

August 3, 2017 by Dan Maloney 23 Comments

Some people just won’t wake up. Alarm clocks don’t cut it, flashing lights won’t work, loud music just becomes the soundtrack of an impenetrable dream. Maybe an alarm clock that rudely yanks the covers off the bed will do the trick.

Or not, but [1up Living] decided to give it a go. His mechanism is brutally simple — a large barrel under the foot of the bed around which the warm, cozy bedclothes can wind. An alarm clock is rigged with a switch on the bell to tell an Arduino to wind the drum and expose your sleeping form to the harsh, cold world. To be honest, the fact that this is powered by a 2000-lb winch that would have little trouble dismembering anyone who got caught up in the works is a bit scary. But we understand that the project is not meant to be a practical solution to oversleeping; if it were, [1up Living] might be better off using the winch to pull the bottom sheet to disgorge the sleeper from the bed entirely.

Something gentler to suit your oversleeping needs might be this Neopixel sunrise clock to coax you out of bed naturally.

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Classing Up A RetroPie Arcade With A Wine Barrel

September 20, 2016 by Cameron Coward 20 Comments

Arcade cabinets are a lot of fun, and something most of us would probably like in our homes. Unfortunately, space and decor constraints often make them impractical. Or, at least, that’s what our significant others tell us. Surely there must be a workaround, right?

Right! In this case, the workaround [sid981] came up with was to build a RetroPie arcade into a fancy looking wine barrel. The electronics are pretty much what you’d expect for a RetroPie system, and the screen is set into the top of the barrel. Control is handled by a wireless controller that can be tucked away when it’s not in use, and a glass top simultaneously protects the screen and lets guests use the barrel as a bar table.

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Retrotechtacular: Coopering Guinness Barrels By Hand

July 21, 2015 by Kristina Panos 22 Comments

For almost exactly 200 years, the Guinness brewery in Dublin, Ireland employed extremely skilled craftsmen to shape and construct wooden casks by hand. These men were called coopers, and plying their trade required several years of apprenticeship. The cooperage was a kind of closed society as many of the positions were passed down through generations of families. With the rise of aluminium and then stainless steel barrels in the late 1950s, the master coopers of Guinness became a dying breed.

Almost every step of the coopering process shown in this film is done without any kind of precise measurement. A master cooper like [Dick Flanagan] here needs only his eyes and his practiced judgment. His barrels start out as oak planks called ‘staves’ that have been drying in racks for at least two years. A cooper selects the staves that strike his fancy and he saws off the ends. This seems to be the only part of the process where a power tool is used.

The cooper shapes each stave by hand with axe and adze so that its ends are tapered just so. Once he has shaped enough of them to make a barrel, he arranges them in a cylinder around the inside of a metal band known as a hoop. The bound staves are steamed for half an hour to make them pliable enough for shaping.

After steaming, the splayed end of the staves are bound with wire rope to pull them close enough together that a hoop can be fitted over them. The inside of the cask is then charred with burning oak shavings, a process that seals the wood and removes its acidity. After this, the ends are sanded and the bunghole is drilled.

For each barrel, the cooper crafts a custom set of hoops. These are installed after the outside of the barrel has been shaved smooth. Finally, the heads that cap each end of the cask are made from more oak staves held together with dowel rods. This is the only time the cooper uses a tool to measure anything, and he does so to achieve the proper circumference on the heads. He bevels the edges so the heads will fit into bored-out grooves in the cask walls. Once they’re seated, the keg is ready for dark, rich stout.

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Coopering Wine Barrels

June 17, 2013 by Caleb Kraft No comments

The process of making a high quality wine barrel is still done very much by hand. Each piece of wood is hand selected, even from the point of purchasing specific logs at auctions. In this video he is using many power tools and modern techniques, but still performing everything himself. I couldn’t find any videos of coopers using only hand tools, let me know if you find one.