Author: Tyler August

276 Articles

POV Globe Takes To The Skies

October 22, 2025 by 12 Comments

LED billboards are cyberpunk-dystopian enough for most, but it can get worse. For example, this project by [Concept Crafted Creations] that takes the whole concept and takes it airborn (literally) in the form of a flying POV sphere called “Zippy”.

We love persistence-of-vision (POV) displays, and have featured plenty before, from the very complicated to the fairly simple. The idea is simple: take one or more rings of LEDs and spin them rapidly enough that the persistence-of-vision effect creates a solid image in your visual field. We covered the basics years back. “Zippy” has one ring of addressable LEDs that surrounds the thing that makes it unique: the quadcopter at its core. None of those other projects could fly, after all.

You might imagine a big, spinning ring is going to have a lot of torque to cancel out, and that is true — about 2.3 kgf — and it led to a lot of prototypes crashing early on. After trying to use flaps to direct the downwash of the quadcopter rotors to counter the spin, [Concept Crafted Creations] eventually added two extra props for yaw control, and that seemed to do the trick. We say “quadcopter” because that’s the configuration, but Zippy ended up heavy and needs eight lift motors to fly. PVC pipe and PLA aren’t the lightest build materials, after all. That’s ten props, total, plus another outrunner to spin the POV ring. All those motors, plus the current draw of the LEDs means the flight time might not impress — but Zippy sure does, at last as long as the batteries hold out.

There’s something eye-catching about POV displays, and seeing this one drifting upwards like Kang and Kodos decided to steal the Los Vegas Sphere is even more arresting. That made the crash at the end of the video sad to see, but [Concept Crafted Creations] hasn’t ruled out rebuilding it if his viewers show enough interest. So if you like what you see, head over to YouTube and leave an encouraging comment for him to try, try again. Continue reading “POV Globe Takes To The Skies” →

Ore Formation: Return Of The Revenge Of The Fluids

October 21, 2025 by 16 Comments

In the last edition of our ongoing series on how planets get ore– those wonderful rocks rich in industrial minerals worth mining– we started talking about hydrothermal fluid deposits. Hydrothermal fluid is the very hot, very salty, very corrosive water that sweats out of magma as it cools underground and under pressure.

We learned that if the fluid stays in the magma chamber and encourages the growth of large crystals there, we call that a pegmatite deposit. If it escapes following cracks in the surface rock, it creates the characteristic veins of an orogenic deposit. What if the fluid gets out of the magma chamber, but doesn’t find any cracks?

Perhaps the surrounding rock is slightly permeable to water, and the hydrothermal fluid can force its way through, eating away at the base rock and remineralizing it with new metals as it goes. That can happen! We call it a porphyry deposit, particularly in igneous rock. It’s not exactly surprising that a hydrothermal fluid would find igneous rock: the fluid is volcanic in origin, after all, just like igneous rock. (That’s the definition of igneous: a rock of volcanic origin.) Igneous rocks, like granite, tend not to be terribly reactive so the fluid can diffuse through relatively unchanged.

Igneous rocks aren’t the only option, though. If the hydrothermal fluid hits carbonates, well, I did mention it’s acidic, right? Acid and carbonates are not friends, so all sorts of chemistry happens, such that geologists give the resulting metamorphic formation a special name: skarn. Though similar in origin, skarns are often considered a different type of deposit, so we’ll talk about the simpler case, diffusion through non-reactive rocks, before getting back to the rocks that sound like an 80s fantasy villain. (Beware Lord Skarn!)

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Fail Of The Week: Beaker To Benchy More Bothersome Than Believed

October 20, 2025 by No comments

Making nylon plastic from raw chemicals used to be a very common demo; depending where and when you grew up, you may well have done it in high school or even earlier. What’s not common is taking that nylon and doing something with it, like, say extruding it into filament to make a benchy. [Startup Chuck] shows us there might be a reason for that. (Video, embedded below.)

It starts out well enough: sebacoyl chloride and hexamethaline diamine mix up and do their polymerizing tango to make some nylon, just like we remember. (Some of us also got to play with mercury bare-handed; safety standards have changed and you’ll want to be very careful if you try this reaction at home). The string of nylon [Chuck] pulls from the beaker even looks a little bit like filament for a second, at least until it breaks and gets tossed into a blobby mess. We wonder if it would be possible to pull nylon directly into 1.75 mm filament with the proper technique, but quality control would be a big issue. Even if you could get a consistent diameter, there’d likely be too much solvent trapped inside to safely print.

Of course, melting the nylon with a blowtorch and trying to manually push the liquid through a die to create filament has its own quality control problems. That’s actually where this ends: no filament, and definitely no benchy. [Chuck] leaves the challenge open to anyone else who wants to take the crown. Perhaps one of you can show him how it’s done. We suspect it would be easiest to dry the homemade nylon and shred it into granules and only then extrude them, like was done with polypropylene in this mask-recycling project. Making filament from granules or pellets is something we’ve seen more than once over the years.

If you really want to make plastic from scratch, ordering monomers from Sigma-Aldrich might not cut it for ultimate bragging rights; other people are starting with pulling CO2 from the atmosphere.

Thanks to [Chaz] for the tip! Remember that the tips line isn’t just for your successes– anything interesting can find its home here.

Continue reading “Fail Of The Week: Beaker To Benchy More Bothersome Than Believed” →

Left: old and busted. Right: New hotness.

Game Of Theseus Gets Graphics Upgrade, Force Feedback 30 Years On

October 19, 2025 by 9 Comments

Indycar Racing 2 was a good game, back in 1995; in some ways, it was the Crysis of the Clinton years, in that most mortals could not run it to its full potential when it was new. Still, that potential was surely fairly limited, as we’re talking about a DOS game from 30 years ago. Sure, it was limited– but limits are meant to be broken, and games are made to be modded. [TedMeat] has made a video showing the updates. (Embedded below.)

It turns out there was a 3D-accelerated version sold with the short-lived Rendition graphics cards. That version is what let the community upscale everything to the absurd resolutions our modern monitors are capable of. Goodbye SVGA, hello HD. Specifically, [sharangad] has created a wrapper to translate the Rendition API to modern hardware. It doesn’t sound like higher-res textures have been modded in, in which case this looks spectacular for graphics designed in 1995. It’s not the latest Forza, but for what it is, it impresses.

The second hack [TedMeat] discusses is a mod by [GPLaps] that pulls physics values from game memory to throw to a modern force-feedback wheel, and it shows just how good the physics was in 1995. You really can feel what’s going on– stopping a skid before it starts, for example. That’s normal these days, but for the kids playing with a keyboard in 1995, it would have been totally mind-blowing.

As tipster [Keith Olson] put it: “What can I say? Fans gonna fan!” — and we’re just as grateful for that fact as we are for the tipoff. If you’re in a fandom that’s hacked its way to keep old favourites alive, we’d love to hear about it: submit a tip.

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A Solar Oven For Cloudy Days

October 18, 2025 by 19 Comments

Every Boy Scout or Girl Guide probably had the experience of building a simple solar oven: an insulated box, some aluminum foil, and plastic wrap, and voila! On warm, sunny, summer days, you can bake. On cloudy days, well, you need another plan. The redoubtable [Kris De Decker] and [Marie Verdeil] provide one, with this solar-electric oven over on LowTechMagazine.

Now, you might be wondering: what’s special here? Can’t I just plug a full electric range-oven into the inverter hooked to my Powerwall? Well, yes, Moneybags, you could — if you had a large enough solar setup to offset the storage and inverter losses, that is. But if you only have a few panels, you need to make every watt count. Indeed, this build was inspired by [Kris]’ earlier attempt to power his apartment with solar panels on his balcony. His electric oven is one of the things that stymied him at that time. (Not because cooking took too much energy, but because it took too much power for his tiny battery to supply at once.)

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A Deep Dive Into Molten Bismuth

October 16, 2025 by 2 Comments

Bismuth is known for a few things: its low melting point, high density, and psychedelic hopper crystals. A literal deep-dive into any molten metal would be a terrible idea, regardless of low melting point, but [Electron Impressions]’s video on “Why Do Bismuth Crystals Look Like That” may be the most educational eight minutes posted to YouTube in the past week.

The whole video is worth a watch, but since spoilers are the point of these articles, we’ll let you in on the secret: it all comes down to Free Energy. No, not the perpetual motion scam sort of free energy, but the potential that is minimized in any chemical reaction. There’s potential energy to be had in crystal formation, after all, and nature is always (to the extent possible) going to minimize the amount left on the table.

In bismuth crystals– at least when you have a pot slowly cooling at standard temperature and pressure–that means instead of a large version of the rhombahedral crystal you might naively expect if you’ve tried growing salt or sugar crystals in beakers, you get the madman’s maze that actually emerges. The reason for this is that atoms are preferentially deposited onto the vertexes and edges of the growing crystal rather than the face. That tends to lead to more vertexes and edges until you get the fractal spirals that a good bismuth crystal is known for. (It’s not unlike the mechanism by which the dreaded tin whiskers grow, as a matter of fact.)

Bismuth isn’t actually special in this respect; indeed, nothing in this video would not apply to other metals, in the right conditions. It just so happens that “the right conditions” in terms of crystal growth and the cooling of the melt are trivial to achieve when melting Bismuth in a way that they aren’t when melting, say, Aluminum in the back yard. [Electron Impressions] doesn’t mention because he is laser-focused on Bismuth here, but hopper crystals of everything from table salt to gold have been produced in the lab. When cooling goes to quick, it’s “any port in a storm” and atoms slam into solid phase without a care for the crystal structure, and you get fine-grained, polycrystaline solids; when it goes slowly enough, the underlying crystal geometry can dominate. Hopper crystals exist in a weird and delightful middle ground that’s totally worth eight minutes to learn about.

Aside from being easy to grow into delightful crystals, bismuth can also be useful when desoldering, and, oddly enough, making the world’s fastest transistor.

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After Trucking Them Home, Old Solar Panels Keep On Trucking

October 16, 2025 by 69 Comments

The fact that there exist in our world flat rocks that make lightning when you point them at the sun is one of the most unappreciated bits of wizardry in this modern age. As hackers, we love all this of techno-wizardry–but some of us abhor paying full price for it. Like cars, one way to get a great discount is to buy used. [Backyard Solar Project] helped a friend analyze some 14-year-old panels to see just how they’d held up over the years, and it was actually better than we might have expected.

The big polycrystalline panels were rated at 235 W when new, and they got 6 of them for the low, low price of “get this junk off my property”. Big panels are a bit of a pain to move, but that’s still a great deal. Especially considering that after cleaning they averaged 180 W, a capacity factor of 77%. Before cleaning 14 years worth of accumulated grime cost about eight watts, on average, an argument for cleaning your panels. Under the same lighting conditions, the modern panel (rated to 200 W) was giving 82% of rated output.

That implies that after 14 years, the panels are still at about 94% of their original factory output, assuming the factory wasn’t being overoptimistic about the numbers to begin with. Still, assuming you can trust the marketing, a half a percent power drop per year isn’t too bad. It’s also believable, since the US National Renewably Energy Laboratory (yes, they have one) has done tests that put that better than the average of 0.75 %/yr. Of course the average American solar panel lives in a hotter climate than [Backyard Solar Project], which helps explain the slower degradation.

Now, we’re not your Dad or your accountant, so we’re not going to tell you if used solar panels are worth the effort. On the one hand, they still work, but on the other hand, the density is quite a bit lower. Just look at that sleek, modern 200 W panel next to the old 235 W unit. If you’re area-limited, you might want to spring for new, or at least the more energy-dense monocrystalline panels that have become standard the last 5 years or so, which aren’t likely to be given away just yet. On the gripping hand, free is free, and most of us are much more constrained by budget than by area. If nothing else, you might have a fence to stick old panels against; the vertical orientation is surprisingly effective at higher latitudes.

Continue reading “After Trucking Them Home, Old Solar Panels Keep On Trucking” →