Honor Thy Error

February 14, 2026 by Elliot Williams 2 Comments

Musician Brian Eno’s Oblique Strategies are like a Tarot card deck full of whimsical ideas meant to break up a creative-block situation, particularly in the recording studio. They’re loads of fun to pick one at random and actually try to follow the advice, as intended, but some of them are just plain good advice for creatives.

One that keeps haunting me is “Honor thy error as a hidden intention”, which basically boils down to taking a “mistake” and seeing where it leads you if you had meant to do it. I was just now putting the finishing touches on this week’s Hackaday Podcast, and noticed that we have been honoring a mistake for the past 350-something shows. Here’s how it happened.

When Mike and I recorded the first-ever podcast, I had no idea how to go about doing it. But I grew up in Nashville, and know my way around the inside of a music studio, and I’ve also got more 1990s-era music equipment than I probably need. So rather than do the reasonable thing, like edit the recording on the computer, we recorded to an archaic Roland VS-880 “Digital Studio” which is basically the glorified descendant of those old four-track cassette Portastudios.

If you edit audio in hardware, you can’t really see what you’re doing – you have to listen to it. And so, when I failed to notice that Mike and I were saying “OK, are you ready?” and “Sure, let’s go!”, it got mixed in with the lead-in music before we started the show off for real. But somehow, we said it exactly in time with the music, and it actually sounded good. So we had a short laugh about it and kept it.

And that’s why, eight years later, we toss random snippets of conversations into the intro music to spice it up. It was a mistake that worked. Had we been editing on the computer, we would have noticed the extra audio and erased it with a swift click of the mouse, but because we had to go back and listen to it, we invented a new tradition. Honor thy error indeed.

There’s Always Room For 3D Printed Batteries

February 14, 2026 by Al Williams 7 Comments

There are many applications where you have limits on how much you can cram into a particular space. There are also many applications where you need as much battery as you can get. At the intersection of those applications, you may soon be able to 3D print custom batteries to fit into oddly shaped spaces that might otherwise go to waste.

Commercial batteries are typically cylindrical or rectangular. In theory, you could build tooling to make batteries of any size or shape you want, but it’s an expensive process in small quantities. [Lawrence Ulrich] on Spectrum talks about a new process, developed by [Gabe Elias], that can print anodes, cathodes, separators, and casings for custom battery shapes with no costly tooling.

As an example, consider an unmanned aerial vehicle crammed with avionics. You could put off-the-shelf batteries in the wings, but you’ll end up wasting a lot of space. A custom battery could fill the wing’s interior completely. The post also mentions batteries shaped like the earpieces of a pair of smart glasses.

A prototype showed that in the space of 48 cylindrical cells, the new process could deliver a printed battery that uses 35% more of the available volume and a 50% boost in energy density.

Could you do this yourself? Maybe, but it won’t be trivial. The current process requires a liquid electrolyte and the ability to produce thin layers of exotic materials. What oddly-shaped battery would you like to see? Us? We’d like to have a battery for a laptop that was spread uniformly so there wasn’t a heavy side that has the battery.

Building The Most Simple Motor In Mostly LEGO

February 14, 2026 by Maya Posch 6 Comments

Although [Jamie’s Brick Jams] has made many far more complicated motor design in the past, it’s nice to go back to the basics and make a motor that uses as few parts as possible. This particular design starts off with a driver coil and a magnetic rotor that uses two neodymium magnets. By balancing these magnets on both sides of an axis just right it should spin smoothly.

The circuit for the simple motor. (Credit: Jamie's Brick Jams, YouTube) — The circuit for the simple motor. (Credit: Jamie’s Brick Jams, YouTube)

First this driver coil is energized with a 9 V battery to confirm that it does in fact spin when briefly applying power, though this means that you need to constantly apply pulses of power to make it keep spinning. To this end a second coil is added, which senses when a magnet passes by.

This sense coil is connected to a small circuit containing a TIP31C NPN power transistor and a LED. While the transistor is probably overkill here, it’ll definitely work. The circuit is shown in the image, with the transistor pins from left to right being Base-Collector-Emitter. This means that the sensor coil being triggered by a passing magnet turns the transistor on for a brief moment, which sends a surge of power through the driver coil, thus pushing the rotor in a typical kicker configuration.

Obviously, the polarity matters here, so switching the leads of one of the coils may be needed if it doesn’t want to spin. The LED is technically optional as well, but it provides an indicator of activity. From this basic design a larger LEGO motor is also built that contains many more magnets in a disc along with two circular coils, but even the first version turns out to be more than powerful enough to drive a little car around.

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Rock Sphere Machine Produces Off The Charts Satisfaction

February 13, 2026 by Donald Papp 3 Comments

[Michigan Rocks] says he avoided making rock spheres for a long time on account of the time and cost he imagined was involved. Well, all that is in the past in light of the fabulous results from his self-built Rock Sphere Machine! Turns out that it’s neither costly to make such a machine, nor particularly time-consuming to create the spheres once things are dialed in. The video is a journey of the very first run of the machine, and it’s a great tour.

The resulting sphere? Super satisfying to hold and handle. The surface is beyond smooth, with an oil-like glossy shine that is utterly dry to the touch.

The basic concept — that of three cordless drills in tension — is adapted from existing designs, but the implementation is all his own. First a rough-cut rock is held between three diamond bits. The drills turn at 100 RPM while a simple water reservoir drips from above. After two hours, there’s a fair bit of slurry and the rock has definitely changed.

[Michigan Rocks] moves on to polishing, which uses the same setup but with progressively-finer grinding pads in place of the cutting bits. This part is also really clever, because the DIY polishing pads are great hacks in and of themselves. They’re made from little more than PVC pipe end caps with hex bolts as shafts. The end caps are filled with epoxy and topped with a slightly concave surface of hook-and-loop fastener. By doing this, he can cut up larger fuzzy-backed polishing pads and stick the pieces to his drill-mounted holders as needed, all the way down to 6000 grit. He shows everything about the pads at the 11:55 mark, and it’s an approach worth keeping in mind.

What is the end result like? See for yourself, but we think [Michigan Rocks] sums it up when he says “I wish you could feel this thing, it feels so smooth. It’s so satisfying to roll around in your hands. I’m so happy I made this machine. This is awesome.”

We’ve seen machines for making wooden spheres but this one makes fantastic use of repurposed stuff like inexpensive cordless drills, and the sort of wood structures anyone with access to hand tools can make.

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Why Diamond Transistors Are So Hard To Make

February 13, 2026 by Maya Posch 6 Comments

Many things about diamonds seem eternal, including the many engineering problems related to making them work as a silicon replacement in semiconductor technology. Yet much like a diamond exposed to a stream of oxygen-rich air and a roughly 750°C heat source, time will eventually erase all of them. As detailed in a recent [Asianometry] video, over the decades the challenges with creating diamond wafers and finding the right way to dope pure diamond have been slowly solved, even if some challenges still remain today.

Diamond is basically the exact opposite as silicon when it comes to suitability as a semiconductor material, with a large bandgap (5.5 eV vs the 1.2 of silicon), and excellent thermal conductivity characteristics. This means that diamond transistors are very reliable, albeit harder to switch, and heat produced during switching is rapidly carried away instead of risking a meltdown as with silicon semiconductors.

Unlike silicon, however, diamond is much harder to turn into wafers as you cannot simply melt graphite and draw perfectly crystallized diamond out of said molten puddle. The journey of getting to the state-of-the art soon-to-be-4″ wafers grown on iridium alongside the current mosaic method is a good indication of the complete pain in the neck that just this challenge already is.

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R2D2 Gets New Brains

February 13, 2026 by Al Williams 4 Comments

While it is fun to get toys that look like your favorite science fiction props, it is less fun when the electronics in them don’t measure up to the physical design. [Steve Gibbs] took a Hasbro R2D2 toy robot and decided to give it a brain upgrade along with enhanced sensors. You can see a video of the robot doing its thing and some build details below.

In this case, the toy from Hasbro was not working at all, so [Steve] saved it from the dumpster. Instead of a repair, he decided to just gut it and rebuild it with modern electronics. The ultrasonic sensor on the forward toe is a dead giveaway.

The robot responds to voice commands better than the original and can play sound effects and clips from Star Wars. You can also control the robot with a phone app. The new or upgraded sensors include microphones, a PIR sensor, a photoresistor to sense light, a smoke and CO₂ sensor, a computer vision camera, and, of course, the ultrasonic range finder.

Some motors and the original speaker are in use, but R2 now sports additional LEDs and servos. All the extras required some surgery on the plastic body. Instead of regular batteries, the ‘bot now uses a LiPo battery, so the old battery compartment was cut out to make more room.

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Inside Raiders Of The Lost Ark (Atari Style)

February 13, 2026 by Al Williams 2 Comments

It’s a bit ironic that an Atari 2600 game based on Raiders of the Lost Ark — a movie about archaeology — is now the subject of its own archaeological expedition as [Dennis Debro] and [Halkun] spent time reverse-engineering the game. Luckily, they shared their findings, so you can enjoy it the same way you can visit a king’s tomb without having to discover it and dig for it. If you don’t remember the game, you might enjoy the demo from [Speedy Walkthroughs] in the video below.

If you are only used to modern software, you might think this is little more than someone dumping the program code and commenting it. However, on these old, limited systems, you have to really understand the actual architecture because there are so many things you have to manage that are specific to the hardware.

For example, the game has two 4K ROM banks that use a strange switching mechanism. The entire game is built around the NTSC television signal. Everything is oriented toward generating the 60 Hz frame rate. Game logic runs during the vertical blanking and over-scan sections to prevent strange visible artifacts due to software running.

This is a fascinating look inside game coding as it existed around 1982. Of course, you can also run everything using emulation. Usually, our reverse engineering is more hardware-related. But we do love these old games, too.

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