A plywood box with a clear plastic front is shown. Three needle gauges are visible on the front of the box, as well as a digital display, several switches, and some indicator lights. At the right of the box, a short copper tube extends from the box.

Building An X-Ray Crystallography Machine

July 7, 2025 by Aaron Beckendorf 9 Comments

X-ray crystallography, like mass spectroscopy and nuclear spectroscopy, is an extremely useful material characterization technique that is unfortunately hard for amateurs to perform. The physical operation isn’t too complicated, however, and as [Farben-X] shows, it’s entirely possible to build an X-ray diffractometer if you’re willing to deal with high voltages, ancient X-ray tubes, and soft X-rays.

[Farben-X] based his diffractometer around an old Soviet BSV-29 structural analysis X-ray tube, which emits X-rays through four beryllium windows. Two ZVS drivers power the tube: one to drive the electron gun’s filament, and one to feed a flyback transformer and Cockroft-Walton voltage multiplier which generate a potential across the tube. The most important part of the imaging system is the X-ray collimator, which [Farben-X] made out of a lead disk with a copper tube mounted in it. A 3D printer nozzle screws into each end of the tube, creating a very narrow path for X-rays, and thus a thin, mostly collimated beam.

To get good diffraction patterns from a crystal, it needed to be a single crystal, and to actually let the X-ray beam pass through, it needed to be a thin crystal. For this, [Farben-X] selected a sodium chloride crystal, a menthol crystal, and a thin sheet of mica. To grow large salt crystals, he used solvent vapor diffusion, which slowly dissolves a suitable solvent vapor in a salt solution, which decreases the salt’s solubility, leading to very slow, fine crystal growth. Afterwards, he redissolved portions of the resulting crystal to make it thinner.

The diffraction pattern generated by a sodium chloride crystal. A slide is shown with a dark black dot in the middle, surrounded by fainter dots. — The diffraction pattern generated by a sodium chloride crystal.

For the actual experiment, [Farben-X] passed the X-ray beam through the crystals, then recorded the diffraction patterns formed on a slide of X-ray sensitive film. This created a pattern of dots around the central beam, indicating diffracted beams. The mathematics for reverse-engineering the crystal structure from this is rather complicated, and [Farben-X] hadn’t gotten to it yet, but it should be possible.

We would recommend a great deal of caution to anyone considering replicating this – a few clips of X-rays inducing flashes in the camera sensor made us particularly concerned – but we do have to admire any hack that coaxed such impressive results out of such a rudimentary setup. If you’re interested in further reading, we’ve covered the basics of X-ray crystallography before. We’ve also seen a few X-ray machines.

A man’s hand is visible holding a large, potato-shaped object in the foreground. A short, white, cylindrical structure is on the top of the potato, with black wires bending back into the potato. A smaller rectangular structure is to one side of it, and a red alligator clip connects to a nail protruding from the potato.

Building A Potato-based GLaDOS As An Introduction To AI

July 6, 2025 by Aaron Beckendorf 5 Comments

Although not nearly as intimidating as her ceiling-mounted hanging arm body, GLaDOS spent a significant portion of the Portal 2 game in a stripped-down computer powered by a potato battery. [Dave] had already made a version of her original body, but it was built around a robotic arm that was too expensive for the project to be really accessible. For his latest project, therefore, he’s created a AI-powered version of GLaDOS’s potato-based incarnation, which also serves as a fun introduction to building AI systems.

[Dave] wanted the system to work offline, so he needed a computer powerful enough to run all of his software locally. He chose an Nvidia Jetson Orin Nano, which was powerful enough to run a workable software system, albeit slowly and with some memory limitations. A potato cell unfortunately doesn’t generate enough power to run a Jetson, and it would be difficult to find a potato large enough to fit the Jetson inside. Instead, [Dave] 3D-printed and painted a potato-shaped enclosure for the Jetson, a microphone, a speaker, and some supplemental electronics.

A large language model handles interactions with the user, but most models were too large to fit on the Jetson. [Dave] eventually selected Llama 3.2, and used LlamaIndex to preprocess information from the Portal wiki for retrieval-augmented generation. The model’s prompt was a bit difficult, but after contacting a prompt engineer, [Dave] managed to get it to respond to the hapless user in an appropriately acerbic manner. For speech generation, [Dave] used Piper after training it on audio files from the Portal wiki, and for speech recognition used Vosk (a good programming exercise, Vosk being, in his words, “somewhat documented”). He’s made all of the final code available on GitHub under the fitting name of PotatOS.

The end result is a handheld device that sarcastically insults anyone seeking its guidance. At least Dave had the good sense not to give this pernicious potato control over his home.

Fastener Fusion: Automating The Art Of Counting

July 6, 2025 by Matt Varian 7 Comments

Counting objects is an ideal task for automation, and when focusing on a single type of object, there are many effective solutions. But what if you need to count hundreds of different objects? That’s the challenge [Christopher] tackled with his latest addition to his impressive automation projects. (Video, embedded below.)

[Christopher] has released a series of videos showcasing a containerized counting system for various fasteners, available on his YouTube channel. Previously, he built remarkable devices to count and sort fastener hardware for automated packaging, but those systems were designed for a single fastener type. He effectively highlights the vast complexity of the fastener ecosystem, where each diameter has dozens of lengths, multiple finishes, various head shapes, and more.

To address this, he developed a machine that accepts standardized containers of fastener hardware. These uniform boxes can hold anything from a small M2 countersunk screw to a large M8 cap head bolt and everything in between. To identify the loaded box and determine the appropriate operations, the machine features an RFID reader that scans each box’s unique tag.

Once a box is loaded, the machine tilts it to begin counting fasteners using a clever combination of moving platforms, an optical sensor, and gravity. A shelf first pushes a random number of fasteners onto an adjustable ledge. A second moving platform then sweeps excess fasteners off, leaving only those properly aligned. It’s no surprise this system has nine degrees of freedom. The ledge then moves into view of a sensor from a flatbed scanner, which detects object locations with an impressive 0.04 mm resolution across its length—remarkable for such an affordable sensor. At this point, the system knows how many fasteners are on the ledge. If the count exceeds the desired number, a sloped opening allows the ledge to lift just high enough to release the correct amount, ensuring precision.

The ingenuity continues after the initial count. A secondary counting method uses weight, with a load cell connected to the bin where fasteners drop. A clever over-center mechanism decouples the tilting system from the load cell to ensure accurate readings. We love automation projects, and this one incorporates so many ingenious design elements that it’s sure to inspire others for their future endeavors.

Continue reading “Fastener Fusion: Automating The Art Of Counting” →

Hackaday Links: July 6, 2025

July 6, 2025 by Dan Maloney 9 Comments

Taking delivery of a new vehicle from a dealership is an emotional mixed bag. On the one hand, you’ve had to endure the sales rep’s hunger to close the deal, the tedious negotiations with the classic “Let me run that by my manager,” and the closer who tries to tack on ridiculous extras like paint sealer and ashtray protection. On the other hand, you’re finally at the end of the process, and now you get to play with the Shiny New Thing in your life while pretending it hasn’t caused your financial ruin. Wouldn’t it be nice to skip all those steps in the run-up and just cut right to the delivery? That’s been Tesla’s pitch for a while now, and they finally made good on the promise with their first self-driving delivery.
Continue reading “Hackaday Links: July 6, 2025” →

Diagnosing Whisker Failure Mode In AF114 And Similar Transistors

July 6, 2025 by Maya Posch 13 Comments

The inside of this AF117 transistor can was a thriving whisker ecosystem. (Credit: Anthony Francis-Jones)

AF114 germanium transistors and related ones like the AF115 through AF117 were quite popular during the 1960s, but they quickly developed a reputation for failure. This is due to what should have made them more reliable, namely the can shielding the germanium transistor inside that is connected with a fourth ‘screen’ pin. This failure mode is demonstrated in a video by [Anthony Francis-Jones] in which he tests a number of new-old-stock AF-series transistors only for them all to test faulty and show clear whisker growth on the can’s exterior.

Naturally, the next step was to cut one of these defective transistors open to see whether the whiskers could be caught in the act. For this a pipe cutter was used on the fairly beefy can, which turned out to rather effective and gave great access to the inside of these 1960s-era components. The insides of the cans were as expected bristling with whiskers.

The AF11x family of transistors are high-frequency PNP transistors that saw frequent use in everything from consumer radios to just about anything else that did RF or audio. It’s worth noting that the material of the can is likely to be zinc and not tin, so these would be zinc whiskers. Many metals like to grow such whiskers, including lead, so the end effect is often a thin conductive strand bridging things that shouldn’t be. Apparently the can itself wasn’t the only source of these whiskers, which adds to the fun.

In the rest of the video [Anthony] shows off the fascinating construction of these germanium transistors, as well as potential repairs to remove the whisker-induced shorts through melting them. This is done by jolting them with a fairly high current from a capacitor. The good news is that this made the component tester see the AF114 as a transistor again, except as a rather confused NPN one. Clearly this isn’t an easy fix, and it would be temporary at best anyway, as the whiskers will never stop growing.

Continue reading “Diagnosing Whisker Failure Mode In AF114 And Similar Transistors” →

Does Made-in-America Make Sense For PCB Prototyping?

July 6, 2025 by Tyler August 94 Comments

These are tough times for American hackers, and rife with uncertainty. Trade wars are on, off, on again– who can keep track? If you’re used to getting everything from China, that can really cramp your style. [Jeremy Cook] took the time to write up his experience prototyping with American-made PCBs, just in time for us to totally miss Independence Day.

The project was a simple nightlight, using a single LED, a photoresistor, a transistor, and a CR2032 battery. The CR2032 battery does complicate things, though: [Jeremy] figured out a neat way to hold the battery using a PCB cutout, but it needs to be a 0.8 mm board. (That’s going to matter in a moment.) He’s put that PCB on GitHub if you’re interested.

To start off, JLBPCB is the Chinese clearing house of choice for [Jeremy], and they quoted a very cheap $7.10 for 20 boards. The problem was that shipping across the Pacific Ocean, plus the ever-wavering tariff charge, brought the price to $48.08. About five dollars of which was from tariffs; the rest you can put down to the cost of jet fuel and the size of the Pacific Ocean.

On the other hand, OSH Park, was able to get [Jeremy] three of their pretty purple PCBs for $7.75 all-inclusive. Overall, since he’s prototyping and does not want 20 boards this revision, [Jeremy] saves quite a lot by staying local– including the environmental impact of shipping and laxer regulations in China, if that sort of thing matters to you.

The suprizing thing is the turnaround time: [Jeremy] got his pretty purple PCBs from OSH Park a full twenty days after ordering. Similar orders from China take only a week, which is just mind-blowing when you stop and think about the great honking ocean in the way. We could perhaps cut OSH Park some slack in that 0.8 mm boards are not the most common, but their quoted turnaround time for two-layer prototypes is minimum 12 days.

They do offer a “super-swift” option for two-layer boards, but then they lose on price. As [Jeremy] points out, there are always tradeoffs. If you’re really in a hurry, nothing’s faster than milling the boards yourself. Or you could go the old-school toner-transfer etching route.

Our thanks to [Jeremy] for the tip. If you’ve got a better way to prototype, do send us a tip about it. Also, please us know in the comments if you’ve tried an in-country PCB fabricator, and how it compared to the usual offerings from the PRC.

Visiting Our Neighbor Sedna: Feasibility Study Of A Mission To This Planetoid

July 6, 2025 by Maya Posch 25 Comments

Image of Sedna, taken by the Hubble Space telescope in 2004. (Credit: NASA)

While for most people Pluto is the most distant planet in the Solar System, things get a lot more fuzzy once you pass Neptune and enter the realm of trans-Neptunian objects (TNOs). Pluto is probably the most well-known of these, but there are at least a dozen more of such dwarf planets among the TNOs, including 90377 Sedna.

This obviously invites the notion of sending an exploration mission to Sedna, much as was done with Pluto and a range of other TNOs through the New Horizons spacecraft. How practical this would be is investigated in a recent study by [Elena Ancona] and colleagues.

The focus is here on advanced propulsion methods, including nuclear propulsion and solar sails. Although it’s definitely possible to use a similar mission profile as with the New Horizons mission, this would make it another long-duration mission. Rather than a decades-long mission, using a minimally-equipped solar sail spacecraft could knock this down to about seven years, whereas the proposed Direct Fusion Drive (DFD) could do this in ten, but with a much larger payload and the ability do an orbital insertion which would obviously get much more science done.

As for the motivation for a mission to Sedna, its highly eccentric orbit that takes it past the heliopause means that it spends relatively little time being exposed to the Sun’s rays, which should have left much of the surface material intact that was present during the early formation of the Solar System. With our explorations of the Solar System taking us ever further beyond the means of traditional means of space travel, a mission to Sedna might not only expand our horizons, but also provide a tantalizing way to bring much more of the Solar System including the Kuiper belt within easy reach.