Flip-up clock

A Flip Clock That Flips Up, Not Down

The venerable flip clock has become an outsized part of timekeeping culture that belies the simplicity of its mechanism. People collect and restore the electromechanical timepieces with devotion, and even seek to build new kinds of clocks based on split-flap displays. Designs differ, but they all have something in common in their use of gravity to open the leaves and display their numbers.

But what if you turned the flip clock on its head? That’s pretty much what [Shinsaku Hiura] accomplished with a flip clock that stands up the digits rather than flipping them down. The clock consists of three 3D-printed drums that are mounted on a common axle and linked together with gears and a Geneva drive. Each numeral is attached to a drum through a clever cam that makes sure it stands upright when it rotates to the top of the drum, and flops down cleanly as the drum advances. The video below makes the mechanism’s operation clear.

The build instructions helpfully note that “This clock is relatively difficult to make,” and given the extensive troubleshooting instructions offered, we can see how that would be so. It’s not the first time we’ve seen a mechanically challenging design from [Shinsaku Hiura]; this recent one-servo seven-segment display comes to mind.

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Metal 3D printed Benchy

Ender 3 Meets MIG Welder To Make A Metal Benchy — Kind Of

When you can buy a 3D printer at Aldi, you pretty much know that 3D printing has been reduced to practice. At least for the plastic version of 3D printing; metal printing is another thing entirely. It’s easy to squeeze out a little molten plastic in a controlled fashion, but things get a little more — energetic — when you try to do the same with metal.

At least that’s what [Lucas] has been experiencing with his attempts to build a metal 3D printer over on his Cranktown City YouTube channel. Granted, he set himself up for a challenge from the get-go by seeking to stick a MIG welder onto an Ender 3, a platform that in no way was ready for the abuse it was about to endure. Part 1 of the video series below shows the first attempt, which ended badly for both the printer and for the prints.

But that first prototype, melted parts notwithstanding, gave [Lucas] enough to go on for the improvements of version 2, including a better build plate, heat shielding for the printer’s tender bits, and a legit MIG welder wire feeder. [Lucas] also built current control in, with a clever non-destructive interface to the welder controls. These improvements were enough to attempt a Benchy print, which started out pretty decent but got a bit droopy toward the end.

As imperfect as it is, the Benchy is a vast improvement over the formless blobs from version 1, and the printer holds quite a bit of promise for the future. One thing you can’t accuse [Lucas] of is giving up on a project too easily; after all, he built a laser cutter from scratch, including the laser tube.

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wifi scanner

Visualizing WiFi With A Converted 3D Printer

We all know we live in a soup of electromagnetic radiation, everything from AM radio broadcasts to cosmic rays. Some of it is useful, some is a nuisance, but all of it is invisible. We know it’s there, but we have no idea what the fields look like. Unless you put something like this 3D WiFi field strength visualizer to work, of course.

Granted, based as it is on the gantry of an old 3D printer, [Neumi]’s WiFi scanner has a somewhat limited work envelope. A NodeMCU ESP32 module rides where the printer’s extruder normally resides, and scans through a series of points one centimeter apart. A received signal strength indicator (RSSI) reading is taken from the NodeMCU’s WiFi at each point, and the position and RSSI data for each point are saved to a CSV file. A couple of Python programs then digest the raw data to produce both 2D and 3D scans. The 3D scans are the most revealing — you can actually see a 12.5-cm spacing of signal strength, which corresponds to the wavelength of 2.4-GHz WiFi. The video below shows the data capture process and some of the visualizations.

While it’s still pretty cool at this scale, we’d love to see this scaled up. [Neumi] has already done a large-scale 3D visualization project, using ultrasound rather than radio waves, so he’s had some experience in this area. But perhaps a cable bot or something similar would work for a room-sized experiment. A nice touch would be using an SDR dongle to collect signal strength data, too — it would allow you to look at different parts of the spectrum.

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wood strength tester

Shop-Built Rig Measures Strength Of Wood Accurately

Wood is an incredibly versatile material, but like everything else, it has its limits. Build a chair from weak wood and the worst that can happen is probably not that bad. But if you build machine tools from wood, the stakes for using the wrong wood can be a bit higher.

That’s the thinking behind the wood strength testing setup [Matthias Wandel] came up with. Previously, he had a somewhat jury-rigged test setup with a hydraulic bottle jack to apply force to the test piece and a bathroom scale to make measurements. That setup was suboptimal, so version two used a jackscrew to apply the force, but the bathroom scale still left the measurements open to interpretation. Version three, the topic of the video below, went with strain gauges and an A/D converter connected to a Raspberry Pi to automate data collection. The jackscrew was also integrated into the test setup with a stepper motor and, of course, [Matthias]’ famous wooden gears.

While the test rig is pretty simple in design, there’s a lot of subtlety to the calibration to make sure that it’s measuring the test material itself and not just compliance within the mechanism. It’s just another in a long line of data-gathering exercises that [Matthias] seems to groove on, like his recent woodshop electrical explorations.

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model rocketry

Retrotechtacular: Junior Missile Men Of The 1960s

Just like the imaginative kids depicted in “Junior Missile Men in Action,” you’ll have to employ a fair bit of your own imagination to figure out what was going on in the original film, which seems to have suffered a bit — OK, a lot — from multiple rounds of digitization and format conversion. [GarageManCave] tells us he found the film on a newsgroup back in the 1990s, but only recently uploaded it to YouTube. It’s hard to watch, but worth it for anyone who spent hours building an Estes model rocket and had that gut-check moment when sliding it onto the guide rail and getting it ready for launch. Would it go? Would it survive the trip? Or would it end up hanging from a tree branch, or lost in the high grass that always seemed to be ready to eat model rockets, planes, Frisbees, or pretty much anything that was fun?

Model rocketry was most definitely good, clean fun, even with the rotten egg stink of the propellant and the risk of failure. To mitigate those risks, the West Covina Model Rocket Society, the group the film focuses on, was formed in the 1960s. The boys and girls pictured had the distinct advantage of living in an area where many of their parents were employed by the aerospace industry, and the influence of trained engineers shows — weekly build sessions, well-organized range days, and even theodolites to track the rockets and calculate their altitude. They even test-fired rockets from miniature silos, and mimicked a Polaris missile launch by firing a model from a bucket of water. It was far more intensive and organized than the early rocketry exposure most of us got, and has the look and feel of a FIRST robotics group today.

Given the membership numbers the WCMRS boasted of in its heyday, and the fact that model rocketry was often the “gateway drug” into the hacking lifestyle, there’s a good chance that someone in the Hackaday community got their start out in that park in West Covina, or perhaps was even in the film. If you’re out there, let us know in the comments — we’d love to hear a first-hand report on what the club was like, and how it helped you get started.

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Hackaday Links: November 21, 2021

As the most spendiest time of the year rapidly approaches, it’s good to know that your hard-earned money doesn’t have to go towards gifts that are probably still sitting in the dank holds of container ships sitting at anchor off the coast of California. At least not if you shop the Tindie Cyber Sale that started yesterday and goes through December 5. There’s a lot of cool stuff on sale, so it shouldn’t be too hard to find something; to sweeten the deal, Jasmine tells us that there will be extra deals going live on Black Friday and Cyber Monday. But wait, there’s more — follow Tindie on Twitter for bonus discount codes.

Blue is the old black, which was the new blue? At least when it comes to “Screens of Death” it is, since Microsoft announced the Windows 11 BSOD will revert back from its recent black makeover to the more familiar blue theme. You’ll have to scroll down a bit, perhaps three-quarters of the way through the list of changes. Again, the change seems completely cosmetic and minor, but we’d still love to know what kind of research went into making a decision like this.

From the “One Man’s Trash” department, we have a request for help from reader Mike Drew who picked up a bunch — like, a thousand — old tablet computers. They originally ran Windows but they can run Linux Mint just fine, and while they lack batteries and the back cover, they’re otherwise complete and in usable condition, at least judging by the pictures he shared. These were destined for the landfill, but Mike is willing to send batches of 10 — no single units, please — to anyone who can cover the cost of packaging and shipping. Mike says he’ll be wiping the tablets and installing Mint, and will throw in a couple of battery cables and a simple instruction sheet to get you started. If you’re interested, Mike can be reached at michael.l.drew@gmail.com. Domestic shipping only, please. Here’s hoping you can help a fellow hacker reclaim a room in his house.

Answering the important questions: it turns out that Thanos couldn’t have snapped half of the universe out of existence after all. That conclusion comes from a scientific paper, appearing in the Journal of the Royal Society. While not setting out to answer if a nigh-invulnerable, giant purple supervillain could snap his fingers, it’s pretty intuitive that wearing any kind of gloves, let alone a jewel-encrusted metal gauntlet, makes it hard to snap one’s fingers. But the mechanics of snapping is actually pretty cool, and has implications beyond biomechanics. According to the paper, snapping is actually an example of latch-mediated spring actuation, with examples throughout the plant and animal kingdoms, including the vicious “one-inch punch” of the tiny mantis shrimp. It turns out that a properly executed human finger snap is pretty darn snappy — it takes about seven milliseconds to complete, compared to 150 milliseconds for an eye blink.

And finally, it seems like someone over at Id Software is a bit confused. The story began when a metal guitarist named Dustin Mitchell stumbled across the term “doomscroll” and decided that it would make a great name for a progressive thrash metal band. After diligently filing a trademark application with the US Patent and Trademark Office, he got an email from an attorney for Id saying they were going to challenge the trademark, apparently because they feel like it will cause confusion with their flagship DOOM franchise. It’s hard to see how anyone who lived through the doomscrolling years of 2020 and 2021 is going to be confused by a thrash metal band and a 30-year-old video game, but we suppose that’s not the point when you’re an attorney. Trademark trolls gonna troll, after all.

FlowIO Takes Top Honors In The 2021 Hackaday Prize

FlowIO Platform, a modular pneumatics controller for soft robotics and smart material projects, took home Grand Prize honors at the 2021 Hackaday Prize. Aside from the prestige of coming out on top of hundreds of projects and bragging rights for winning the biggest hardware design challenge on Earth, the prize carries an award of $25,000 and a Supplyframe DesignLab residency to continue project development. Four other top winners were also announced at the Hackaday Remoticon virtual conference on Saturday evening.

In a year full of challenges, this year’s Hackaday Prize laid down yet another gauntlet: to “Rethink, Refresh, and Rebuild.” We asked everyone to take a good hard look at the systems and processes that make the world work — or in some cases, not work — and reimagine them from a fresh perspective. Are there better ways to do things? What would you come up with if you started from a blank piece of paper? How can you support and engage the next generation of engineers, and inspire them to take up the torch? And what would you come up with if you just let your imagination run wild?

And boy, did you deliver! With almost 500 entries, this year’s judges had quite a task in front of them. Each of the five challenges — Refresh Displays, Rethink Work-From-Home Life, Reimagine Supportive Tech, Redefine Robots, and Reactivate Wildcard — had ten finalists, which formed the pool of entries for the overall prize. And here’s what they came up with.

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