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Hackaday Links: October 6, 2024

Remember that time a giant cylindrical aquarium in a Berlin hotel bar catastrophically failed and left thousands of fish homeless? We sure do, and further recall that at the time, we were very curious about the engineering details of how this structure failed so spectacularly. At the time, we were sure there’d be plenty of follow-up on that score, but life happened and we forgot all about the story. Luckily, a faithful reader named Craig didn’t, and he helpfully ran down a few follow-up articles that came out last year that are worth looking at.

The first is from prosecutors in Berlin with a report offering three possibilities: that the adhesive holding together the acrylic panels of the aquarium failed; that the base of the tank was dented during recent refurbishment; or that the aquarium was refilled too soon after the repairs, leading to the acrylic panels drying out. We’re a little confused by that last one just from an intuitive standpoint, but each of these possibilities seems hand-wavy enough that the report’s executive summary could have been “Meh, Scheiße happens.”

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Pizza Elevator Is The Most Vital Pandemic Technology Of All

Remember the darkest days of lockdown and the pandemic? We were trying to distance ourselves from strangers wherever possible. [scealux]’s pizza elevator was spawned at this time to make apartment pizza deliveries as contactless as possible, and it’s charmingly branded to boot.

The build was intended to loft a pizza from street level to a third-floor balcony (by the American convention, ground floor is numbered one). Built with CNC-cut wooden parts, the elevator frame snap-fits on to the balcony railing. From there, a single spool runs out wire to four corners of the elevator platform.

As the crank is turned, the platform lowers under its own weight. The pizza can then be placed on the platform, and dinner can be lifted back up to the apartment. It’s a simple design, and one that manages to lift the pizza in a stable and flat fashion. With that said, we’d still like to see some anti-tip railings on a potential revision two.

Mock the branding all you will, it’s actually a smart design choice. The recognizable logo made the device’s purpose super obvious to the pizza delivery person, easing the introduction of the technology to a new user base.

If you want to make your own pizza instead of ordering out, you can automate that too.

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The Benefits Of Displacement Ventilation

The world has been shaken to its core by a respiratory virus pandemic. Humanity has been raiding the toolbox for every possible weapon in the fight, whether that be masks, vaccinations, or advanced antiviral treatments.

As far as medicine has come in tackling COVID-19 in the past two years, the ultimate solution would be to cut the number of people exposed to the pathogen in the first place. Improving our ventilation methods may just be a great way to cut down on the spread. After all, it’s what they did in the wake of the Spanish Flu.

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Turning Old Masks Into 3D Printer Filament

Disposable masks have been a necessity during the COVID-19 pandemic, but for all the good they’ve done, their disposal represents a monumental ecological challenge that has largely been ignored in favor of more immediate concerns. What exactly are we supposed to do with the hundreds of billions of masks that are used once or twice and then thrown away?

If the research being conducted at the University of Bristol’s Design and Manufacturing Futures Lab is any indication, at least some of those masks might get a second chance at life as a 3D printed object. Noting that the ubiquitous blue disposable mask is made up largely of polypropylene and not paper as most of us would assume, the team set out to determine if they could process the masks in such a way that they would end up with a filament that could be run through a standard 3D printer. While there’s still some fine tuning to be done, the results so far are exceptionally impressive; especially as it seems the technique is well within the means of the hobbyist.

From masks to usable filament.

The first step in the process, beyond removing the elastic ear straps and any metal strip that might be in the nose, is to heat a stack of masks between two pieces of non-stick paper with a conventional iron. This causes the masks to melt together, and turn into a solid mass that’s much easier to work with. These congealed masks were then put through a consumer-grade blender to produce the fine polypropylene granules that’re suitable for extrusion.

Mounted vertically, the open source Filastruder takes a hopper-full of polypropylene and extrudes it into a 1.75 mm filament. Or at least, that’s the idea. The team notes that the first test run of filament only had an average diameter of 1.5 mm, so they’re modifying the nozzle and developing a more powerful feed mechanism to get closer to the goal diameter. Even still, by cranking up the extrusion multiplier in the slicing software, the team was able to successfully print objects using the thin polypropylene filament.

This is only-during-a-pandemic recycling, and we’re very excited to see this concept developed further. The team notes that the extrusion temperature of 260 °C (500 °F) is far beyond what’s necessary to kill the COVID-19 virus, though if you planned on attempting this with used masks, we’d imagine they would need to be washed regardless. If the hacker and maker community were able to use their 3D printers to churn out personal protective equipment (PPE) in the early days of the pandemic, it seems only fitting that some of it could now be ground up and printed into something new.

Fight Disease With A Raspberry Pi

Despite the best efforts of scientists around the world, the current global pandemic continues onward. But even if you aren’t working on a new vaccine or trying to curb the virus with some other seemingly miraculous technology, there are a few other ways to help prevent the spread of the virus. By now we all know of ways to do that physically, but now thanks to [James Devine] and a team at CERN we can also model virus exposure directly on our own self-hosted Raspberry Pis.

The program, called the Covid-19 Airborne Risk Assessment (CARA), is able to take in a number of metrics about the size and shape of an area, the number of countermeasures already in place, and plenty of other information in order to provide a computer-generated model of the number of virus particles predicted as a function of time. It can run on a number of different Pi hardware although [James] recommends using the Pi 4 as the model does take up a significant amount of computer resources. Of course, this only generates statistical likelihoods of virus transmission but it does help get a more accurate understanding of specific situations.

For more information on how all of this works, the group at CERN also released a paper about their model. One of the goals of this project is that it is freely available and runs on relatively inexpensive hardware, so hopefully plenty of people around the world are able to easily run it to further develop understanding of how the virus spreads. For other ways of using your own computing power to help fight Covid, don’t forget about Folding@Home for using up all those extra CPU and GPU cycles.

Two views of the M19O2 oxygen concentrator

Design Improvements Make DIY Oxygen Concentrator Even Better

A lot of projects we feature on these pages are of the “one and done” variety — tactical builds that serve a specific purpose with little need for further development. Some projects, though, come out as rough prototypes and then go through multiple rounds of refinement, a process we really enjoy tracking down and following. And when the project is something as important as an oxygen concentrator that can be built and maintained easily, all the better.

The need for cheap oxygen concentrators stems directly from the COVID-19 pandemic, which suggested that high-flow oxygen therapy was a better choice than invasive intubations and mechanical ventilation. But medical-grade oxygen isn’t always easy to come by in all parts of the world, so easily built oxygen concentrators, which rely on the nitrogen-adsorbing properties of the mineral zeolite, are meant to fill the gaps. Early versions of the M19O2 and the related OxyKit concentrator, had a very homebrew feel to them, built on wooden frames as they were. And while the rustic nature of the early builds didn’t detract from their utility, the hackers behind them, including our own [Anool Mahidharia], have been making incremental improvements aimed at not only making the devices work better, but also making them easier to build.

The hackers at Maker’s Asylum have done a fantastic job at documenting their work, with everything posted to a GitHub repo so that anyone can undertake a build. And really, for something as important as making oxygen when it’s needed, there’s really no reason not to give this a try.

Reminder: Bring-A-Hack Is This Thursday August 5th

Hey you! What have you been working on lately? No, wait, don’t tell us just yet! Save the juicy details for the summer edition of Bring-A-Hack. It’s going down in just two days — that’s Thursday, August 5th at 1:00 PM Pacific Daylight time (4pm EDT | 9pm BST/CET). Go register right now!

Historically, Hackaday has attended (or hosted) Bring-a-Hack events as a social activity along with live conference. You grab something off your bench and it gives you a thing to talk about as you see friends old and new. This virtual Bring-a-Hack walks in those footprints — anyone who wants to present their to the group can just type ‘I would like to present’ in the Crowdcast chat once the event gets under way. We also plan to have breakout rooms for more interaction.

If you were too shy to show off one of your projects at the last one of these back in April, now is your chance! Are you building something for the Hackaday Prize? What have you done to make working from home more tolerable? Whatever you’re into, we want to see it, so come and show it off to the hacker elite from around the world. And just because they’re elite, it doesn’t mean they’re elitist: it doesn’t matter what level your project is on. What matters is that you’re passionate about it, and that you probably learned something along the way — something you can share with the community that will bring you many virtual pats on the back.

So go and get registered, shine up those hacks, and we’ll see you there!