RGB image from the projector, with human for scale.

RGB Laser Projector Does Colorful Asteroids And Much More

May 6, 2026 by 12 Comments

Have you thought about building a galvonometer-based laser projector, but don’t know where to start? There are a lot of resources out there, but you could do worse than to check out [Breq] and [Mia]’s laser vector project, which provides a very well-documented and low-cost starting point. They boast that the most expensive part of the project was the ANSI-certified safety glasses, which shows a dedication to safety we wish more people would show when playing with coherent light.

The rest of the parts — from the galvos to the RGB lasers module with dichoric mirrors to keep everything on the same beamline, to the ESP32 module driving everything — was ordered from AliExpress, and not from the most expensive vendors, either. Considering that, it works remarkably well.

If you’re not playing Asteroids on your vector display, why even bother?

Like all DIY laser projectors, this one does vector graphics, sweeping the beam fast enough that the human eye registers crisp, clean lines. Galvonometers, or galvos for short, take analog input, so a DAC is needed — fortunately the ESP32-S2 comes with a pair built in. The custom PCB of course has audio-in for the usual Lissajous lightshow or oscilloscope music, but with an ESP32 as the brains, you can do a lot just inside the projector.

Like what? Well, play Asteroids, for instance, using Wiimote controllers. Project a lovely clock. Render text input in various single-stroke fonts. More to the point, since this is a projector, take arbitrary SVG data and project literally any image you’d like — as long as it doesn’t have too many lines, at least. The galvos in this project are rated at 20,000 points per second, which is not exceedingly fast: they were chosen to meet the budget, not the greatest-possible speed.

More to the point is that this is one of the better-documented projects of this type we’ve seen. [Breq] doesn’t just tell us how to build the projector, but why they designed it that way. We really encourage you to give it a read if you’ve been thinking of getting into this sort of display.

We’ve seen plenty of laser projectors before, most of them producing vector images like this one. If you really must have a raster display, though, that’s also an option. Don’t count out vector images, though — they could even replace your Christmas lights.

Thanks to [CapinRedBeard] for the tip! Remember to send any bright ideas you see to our tips line, coherently lit or no.

Using Hamster Power To Charge A Phone

May 5, 2026 by 22 Comments

It seems fair to say that hamsters are a somewhat divisive pet, between their fluffiness, high-strung nature, short lifespan and incessant squeaking that sounds like some electronic device is trying to tell you something. With that in mind, maybe that having these fuzzy little critter take up some of the daily slack will help endear them to more people. Something like helping to charge mobile devices by converting their frantic exercise wheel time into electrical power. Cue [Flamethrower]’s hamster wheel-powered generator.

Due to the irregular pacing of the hamster on its wheel it makes sense to treat it as an energy harvesting problem, for which the common CJMCU-2557 module – featuring the TI BQ25770 – is a pretty good option. It covers a voltage input from 0.1 – 5.1 V after a cold start minimum of 0.6 V, with a maximum current of 0.1 A.

The modules come with a super capacitor to store collected energy, but you can further charge a connected battery, for which [Flamethrower] used salvaged 18650 Li-ion cells. After letting the hamster do its thing for a night in the – admittedly far too small wheel –  there’s enough power in the cell to at least start charging a smartphone, though sadly it’s not mentioned how much power was harvested.

Hopefully the hamster in question will be overclocked with a larger wheel, along with detailed measurements of how many hamsters it takes to charge the average phone.

Continue reading “Using Hamster Power To Charge A Phone” →

3D reconstruction of x-rayed worms. X-ray absorbing particles in the guts are shown in white.

Earthworms Don’t Bio-Accumulate Microplastics, So There May Be Hope For Us

May 5, 2026 by 24 Comments

Microplastics absolutely saturate the Earth’s environment, and that’s probably not a good thing unless you’re looking for a sediment marker for the Anthropocene period. On the other hand, environmental contamination only becomes a really big problem if it bioaccumulates– that is, builds up in the tissues of plants and animals. At least when it comes to worms, that’s not the case with microplastics, according to new research from the Canadian Light Source at the University of Saskatchewan.

Pictured: Not an Igloo.
Credit: David Stobbe / Stobbe Photography, via University of Saskatchewan

The Canadian Light Source isn’t just some hoseheads in an igloo with a flashlight– it’s a 2.9 GeV Synchrotron tuned to produce high-energy photons. Back when Synchrotrons were used for particle physics, Synchrotron radiation was a very annoying energy sink, but nobody cares about 2.9 GeV electrons anymore. So rather than slam them into each other or a static target, the electrons just whip about endlessly, giving off both soft- and hard X-rays for material science studies– or, in this case, to observe the passage of polyethelyne microplastic particles through the guts of some very confused earth worms. To make them detectable by x-ray, the polyethylene was bonded to barium sulfate, an x-ray absorber. Equally opaque barium titanite glass microspheres were used with different worms, as a control.

Despite being fed soil enriched with far more plastic than you’ll find outside of a 3D print farm, it seems the worm’s digestive system was able to reject the particles, even those as fine as 5 microns. That’s a good thing, because if the worms were absorbing plastic from the soil, it’s likely their predators would absorb it from the flesh of the worms, so and so forth up the food chain in the sort of cascade that made DDT a problem and makes mercury compounds so serious. If the worms are rejecting these compounds, there’s a chance other creatures can too– and at the very least, it means they aren’t building up on this bottom rung of the foot chain. If you’re looking for a more technical read, the full paper is available here.

It’s too early to say what this means for how microplastics get into humans and other animals, but it’s hopeful. Equally hopeful was the recent finding that studies that don’t rely on football-field sized X-ray machines might be picking up on microplastics from lab gloves, skewing results.

Header image: the digestive systems of earth worms as imaged by the Canadian Light Source. Credit Letwin, et al,
Environmental Toxicology and Chemistry, vgag072, https://doi.org/10.1093/etojnl/vgag072

Defeating The [Works By Design]’s Unpickable Lock

May 5, 2026 by 23 Comments

Even though the very concept of an ‘unpickable lock’ is as plausible as making water not be wet, this doesn’t take away from the intellectual thrill of devising solutions to picking attacks and subsequently circumventing those solutions. Case in point the ‘unpickable’ traveling key lock that [Works by Design] recently featured and sent a few copies off to lock pickers such as [Lock Noob] who gave picking it a shake.

Many of the details and reasoning behind [Works by Design]’s lock design can be found in the original video, with [Lock Noob] going over the basic summary before getting to work trying to pick it.

Rather than trying to bump the tumbler lock mechanism or another indirect approach, the focus is here on an impressioning attack. Although in this traveling key mechanism the physical key is moved inside the lock, the pins of the tumbler lock will leave impressions on the brass blanks when the lock is gently forced to rotate, indicating that there’s still too much material there.

The approach here is thus to slowly file away these sections, with interestingly the plastic pin that [Works by Design] had added to dodge impressioning attacks not being too much of an issue. Thus after over an hour of turning-filing-turning-filing ad nauseam, the lock mechanism rotated, confirming that it had been defeated.

In the subsequent teardown of the lock it can be seen that a plastic pin is indeed rather fragile, with part of its top having been torn off. After replacing this damaged plastic pin with a fresh one, a foil-based impressioning attack is attempted by putting aluminium foil over a skeleton key, but this didn’t quite work out as the pins come in sideways and thus do not leave a useful impression.

Theoretically the pins would press down onto the soft foil, creating an almost immediate impression of the required key. Perhaps that leaving a solid side on the blank would make it work, but this is an approach that would have to be refined.

Either way, it shows that ‘unpickable’ depends on your definition, as ‘1+ hour of filing with knowledge of bitting depths’ would be considered ‘unpickable’ by some. At least it’s not as dramatic as a 2020 [Stuff Made Here] ‘unpickable lock’ hack that we covered, before it got shredded by the [LockPickingLawyer] with resulting list of potential fixes of multiple easy exploits before even having to resort to impressioning.

Considering that traveling key designs generally require at least a tedious impressioning attack, with potential ways to address this in a more substantial way, a redesign featuring these changes would be rather interesting to see picked. If it can defeat the average lockpicking enthusiast including those practicing the legal profession, it’s probably as close to ‘unpickable’ as can be before the bolt cutters and angle grinders are used against any vulnerable parts that aren’t the lock itself.

Continue reading “Defeating The [Works By Design]’s Unpickable Lock” →

A fine steel gear is shown held between a man's fingertips.

Cutting Steel Gears With Homemade EDM

May 5, 2026 by 16 Comments

Electric discharge machining (EDM) may be slower than alternatives like laser cutting, water jets, or a milling machine, but for some applications there’s no alternative: it can cut through any conductive material, no matter how hard, and it leaves no mechanical or thermal stress in the workpiece. Best of all, they’re relatively accessible for a resourceful hacker, such as [Inofid], who recently built the second iteration of his desktop wire EDM.

The EDM’s motion system comes from a cheap desktop CNC router, which had a water tank mounted in its workspace and had the spindle replaced with a wire-management mechanism. The wire-management mechanism needs to continuously wind a tensioned brass wire from one spool through the cutting zone onto another spool. The tensioning system uses two motors: one to pull the wire through, and one to maintain tension by slightly counteracting it, with a tension sensor and Ardunio to maintain the proper tension. If it detects that the wire has broken, it can stop the CNC controller. To keep the wire from breaking or short-circuiting with the workpiece, a current monitor counts sparks between the wire and workpiece and uses this to predict whether the wire is getting too close to the metal, in which case it slows down the movement.

As a first test, [Inofid] cut through a five by three centimeters-thick block of aluminium, taking two hours but producing a clean cut. To speed up the next cut, [Inofid] added a pump and filter to remove sludge from the cutting area. The next cut was an aluminium gear, and then a meshing steel gear, which took about ten hours but turned out well.

EDMs of various kinds appear here from time to time, particularly since the popularization of 3D printers. We’ve even seen one built into a lathe.

Thanks to [Keith Olson] for the tip!

Using NFC To Power Devices Instead Of Qi

May 5, 2026 by 6 Comments

It shouldn’t be any surprise that NFC and similar RFID implementations are capable of providing power to a receiver, since this is after all how RFID tags can work without a battery. The question is more whether you can do more with NFC than just briefly power some low-power circuitry to spit out some data. This is the topic of a recent [Denki Otaku] video.

Although both Qi and NFC use electromagnetic induction, they differ in the frequency and correspondingly the maximum power that they can deliver to a receiver. For NFC this is around a Watt, with the used NFC module supporting up to 250 mW, which already sets the rough scope of what one can expect from an NFC-powered device. That said, an NFC transmitter and receiver can be significantly smaller than those for Qi due to the much higher frequency.

An additional benefit of NFC is that it offers more freedom to the user in its protocol in terms of user data, which is useful for applications where you don’t just want to power a device. In the video an MCU and IMU are powered along with an OLED display, which demonstrates wireless charging as well as data transfer of the IMU data to a second MCU.

The benefits of NFC over Qi would thus be the smaller antenna size, and depending on the used NFC implementation also charging and data transfer at the same time.

Continue reading “Using NFC To Power Devices Instead Of Qi” →

How Giant Tanks Of Fluid Could Help Support The Power Grid

May 5, 2026 by 49 Comments

If you’ve been paying any attention to the renewable energy space, you’ll know that generation isn’t really the problem anymore. Solar panels are cheap, and wind turbines are everywhere. The problem is matching generation with demand—sometimes there’s too much wind and sun, and sometimes there’s not enough. Ideally, you could store that energy somewhere, and deploy it when you need it.

The answer everyone keeps reaching for is lithium-ion batteries, and they work just fine. However, there’s a competing technology that’s been quietly scaling up in the background—the vanadium flow battery. It has some unique advantages that could see it rise to prominence in the world of large-scale grid storage.

Continue reading “How Giant Tanks Of Fluid Could Help Support The Power Grid” →