TechyMagThings

3D printing has been around long enough that everyone’s heard at least one weird trick regarding 3D prints. [Angus] of [Maker’s Muse] puts a few to the test, and came away with one solid tip for releasing TPU from a build platform to which it has unfortunately welded itself.

Flexible filaments tend to stick too well to build plates, which is why an interface layer like a thin layer of glue stick is called for. But what if one forgets to apply it before starting a print job? That can result in a print that is well and truly stuck. Peeling flex filament off a textured PEI bed is a bad time, because the print can tear and tends to leave little bits behind.

[Angus] heard that applying isopropyl alcohol helps release things in that case, so he gives it a try. Lo and behold, it seems to work! See for yourself at 18:10 in the video and keep it in mind if you end up in a similar situation. The print doesn’t exactly fall off on its own, but it does remain in one piece which is more than one can expect otherwise.

Watching isopropyl alcohol help release a stuck print is reminiscent of the way it also removes hot glue from just about any surface. The trick is getting the alcohol to wick in underneath for best results, and the same seems to be true with releasing TPU from a build plate.

One thing to keep in mind when evaluating tips and tricks from over the years is that the landscape changes. Something that maybe seemed to have potential years ago might not make much sense today. A good example is sugar as a bed adhesive, which [Angus] tries out. What started as an experiment in getting PLA to play better with glass build plates years ago doesn’t really carry over to now, with PEI-coated magnetic build platforms pretty much a solved problem. The more likely result nowadays is just a mess.

About a month ago, [Greenhill Forge] built a few solar panels to collect energy from the sun. Unlike solar photovoltaics, which turn sunlight directly into electricity, these were designed to gather solar thermal energy with air. These types of panels can gather a tremendous amount of energy for a very low cost, and although the first video only went into the theory of their operation, his latest video actually shows us how to use that energy in a practical way.

The video starts by building a new solar panel, using upgraded materials and building methods compared to the previous versions which should improve the efficiency. There’s some data analysis of the performance, but at the end of the video [Greenhill Forge] actually hooks one of these up to a clothes dryer to explore its real-world efficacy. This process involves disconnecting the electric heater, removing one of the blower fans, and building a new flange to accept the heated air from the solar panel. A microcontroller keeps an eye on the incoming air temperature and controls a fan to try to hit the target temperature.

After an hour of drying, the test clothing was completely dry, with the only electricity used to turn the drum in the dryer. This is more than an order of magnitude of reduction in the power needed to dry clothes, which is fairly impressive. [Greenhill Forge] also notes that systems like these could augment off-grid systems not only for clothes drying but for home heating, greenhouse heating, or drying out various crops and that they could reduce strain on an electrical system that otherwise relies on resistive heating methods. There are many ways of building these panels, so be sure to check out his first video for ideas.

A fascinating aspect in evolutionary biology is that of convergent evolution — whereby similar structures and functions evolve independently from each other. The highly advanced nervous system of octopuses is a good example here, displaying levels of intelligence and capabilities far beyond those of other cephalopods and matching that of primates, despite no evolutionary link here. Exactly how octopuses developed this rather unique capability remained a mystery, though recent research by [Rishav Mitra] points at the rather unique ribosomes in these animals.

Ribosomes are the molecular machinery at the core of each cell that enable the synthesis of proteins. Due to their highly crucial role, they tend to remain evolutionary unchanged, which makes the big change observed in the octopus (i.e. order Octopoda) in the form of this H88 rRNA break quite remarkable.

This H88 break increases the accuracy of translated proteins, something that is essential for complex nervous systems as it reduces cases of misfolded proteins (proteinopathy). Because of how well-preserved ribosomes are across species, the researchers were able to run a number of experiments including a similar rRNA break in E. coli that confirmed many of the assumptions about how these octopus ribosomes performed.

Since proteinopathy results in misfolded proteins that are either useless or harmful to the organism – as seen in various human diseases – this can especially harm long-lived cells like neurons. Unsurprisingly, we can see a similar change to ribosomes in other animal groups, including that of us primates. Although the reasons for octopuses to develop more complex nervous systems wasn’t due to social pressures but rather to cope with highly complex and dynamic environments, it would seem that both types of environmental pressures led to the same convergent path, with a little ribosomal help.

A problem facing the designers of event badges is this: what happens to the badge after the event? It’s one that designers have tried to solve in many ways with varying levels of success, whether that be by making it a dev board, a games console, a mesh-networked communicator, or as in the case of Electromagnetic Field, a continuing badge for future events. Ar BornHack 2026 they have taken a novel approach, by making it a useful desktop appliance. The BornHack Cyber Ægg is a half-egg-shaped badge with a 3D-printed case, and aside from its on-camp applications it’s both a desktop clock/calendar, and a MeshCore node.

Produced with the assistance of the badge.team European badge makers, it’s an egg-shaped PCB with a Nordic nRF52840 at its heart, a Semtech LoRa module, and an e-paper display. On-site there’s a Tamagotchi-style virtual pet game, an event calender, and an RFID token game, but it’s the other two features that give it a life after the camp. The clock and Meshcore, coupled with its case being designed with a flat spot to sit on a desk, make this badge as much an appliance as it is a badge. This is where it will sit in the Hackaday office, and we’re pretty sure most BornHack attendees will use it thus too.

We like this approach to giving a badge a life after the event, and we look forward to seeing what influence it has on future badges. A badge should be a thing to enjoy, not a piece of e-waste.

In 1675, while transporting a barometer by night, the astronomer Jean Picard noticed a glow inside its glass tube, just above the mercury. As the mercury sloshed and splashed across the surface of the glass, a static electric charge had built up, which was discharging by ionizing the residual gas molecules inside the evacuated tube. [Styropyro] recreated this effect, and found that the dim glow could be made much stronger by adding some noble gas to the tube.

It starts with a simple recreation: he took a volumetric flask, attached a narrow glass stem to the mouth, added some mercury to the flask, evacuated it with a vacuum pump, and sealed off the glass stem. This produced a faint glow when shaken, but it was only really visible under very low light. When [Styropyro] brought it near a Tesla coil, however, it did glow much more brightly.

Backfilling an identical flask with neon to about 40 millitorr produced a much more spectacular result (a low pressure in the tube is necessary, but moderate pressure variations don’t significantly alter the effect). When shaken even slightly, this neon-containing flask produced a bright orange-red glow just above the surface of the mercury. Points of obstruction, such as those in a zig-zag tube, produced a brighter glow. A krypton-containing tube glowed blue, but less brightly than the neon tube.

Since this is, essentially, a triboelectric effect, other materials besides mercury should work; [Styropyro] tested several materials, and found that pieces of Teflon produced a faint glow, and copper beads a somewhat brighter glow. Unfortunately, Galinstan, the obvious replacement for mercury, wets and coats glass, preventing a charge buildup.

Without an added noble gas, the standard glow of barometric light comes from the excitation of mercury vapors, a glow which can also be seen in mercury rectifiers, and which excites the phosphors of fluorescent light bulbs.

Thanks to [Vik Olliver] for the tip!

Railroads might be a nineteenth century technology, but they’re still the backbone of cargo transportation in the 21st century. They’ve also far from run out of innovation, including this one which really just sounds like a hack: painting the rails white to beat the heat.

In the old days, when rails were short and riveted together, this might have been unecesssary; all those joints allowed for a lot of flex. But when you have kilometers of continously welded rail, the thermal expansion starts to matter. A lot. Even if the rails haven’t bent and buckled from excess heat, their capacity goes down. Trains must therefore slow way, way down in hot weather, reducing the overall amount of freight the system can handle.

So, how do you cool the million miles of metal that holds a country together? Paint. Simple white paint sprayed on the side of the rails can bring down temperatures 11 °C (20 °F), according to the Union Pacific Railroad, the first to try this in North America. It might not surprise you that this technique is also being rolled out on the other side of the pond during this summer’s European heat waves. Indeed, it was invented there; the Italians have been doing it for many years now.

If you think reducing solar heat with white paint is good, you can do better than that with special formulations that end up cooler than ambient. It passive cooling also comes in fibre form.

[Dr. Gough] bought a generic USB 3.0 hub on an Asian website. Surely, USB 3 is mature enough that even the cheapest hub will have some IC in it that will work well, right? You’d think so, but a little exploratory surgery showed that the only thing about this hub that was USB 3 were the blue port connectors.

We have a few problem USB hubs ourselves, so it might be worth doing this to any you have lying around. The first clue: most of the connectors on the PCB only have four pins. On closer examination, the hub appears to be a USB 3.0 extension cable with a USB 2.0 hub made from two HS8836A chips.

Not only are these USB 2-only, but all the ports on an HS8836A also share the same USB 1.1 bandwidth. Some hubs can provide multiple ports full 1.1 bandwidth, using the higher-speed USB protocol to the PC as a backhaul.

There were quite a few other issues. Missing solder, cables soldered to the board directly, and no bypass capacitors. The per-port switches cut off USB power, but that wouldn’t stop a device with its own power from connecting. The hub has a barrel jack for power, but it would feed back to the PC, which is bad practice at best.

If you use Linux, try lsusb -t and look at the negotiated speed for your hubs. If they aren’t what you expect, it could be a cable issue, or it could just be that you also have a cheap USB hub. Don’t be surprised if your USB 3 hub shows both a USB 3 and a USB 2 hub; that’s common. But if you only see the USB 2 hub, something is amiss, or someone’s lying.

You can learn a lot about USB 3 reading Hackaday.