Author: Bryan Cockfield

1710 Articles

Kubernetes Cluster Goes Mobile In Pet Carrier

November 18, 2025 by 6 Comments

There’s been a bit of a virtualization revolution going on for the last decade or so, where tools like Docker and LXC have made it possible to quickly deploy server applications without worrying much about dependency issues. Of course as these tools got adopted we needed more tools to scale them easily. Enter Kubernetes, a container orchestration platform that normally herds fleets of microservices in sprawling cloud architectures, but it turns out it’s perfectly happy running on a tiny computer stuffed in a cat carrier.

This was a build for the recent Kubecon in Atlanta, and the project’s creator [Justin] wanted it to have an AI angle to it since the core compute in the backpack is an NVIDIA DGX Spark. When someone scans the QR code, the backpack takes a picture and then runs it through a two-node cluster on the Spark running a local AI model that stylizes the picture and sends it back to the user. Only the AI workload runs on the Spark; [Justin] also is using a LattePanda to handle most of everything else rather than host everything on the Spark.

To get power for the mobile cluster [Justin] is using a small power bank, and with that it gets around three hours of use before it needs to be recharged. Originally it was planned to work on the WiFi at the conference as well but this was unreliable and he switched to using a USB tether to his phone. It was a big hit with the conference goers though, with people using it around every ten minutes while he had it on his back. Of course you don’t need a fancy NVIDIA product to run a portable kubernetes cluster. You can always use a few old phones to run one as well.

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Casting Metal Tools With Kitchen Appliances

November 18, 2025 by 21 Comments

Perhaps the biggest hurdle to starting a home blacksmithing operating is the forge. There’s really no way around having a forge; somehow the metal has to get hot enough to work. Although we might be imagining huge charcoal- or gas-fired monstrosities, [Shake the Future] has figured out how to use an unmodified, standard microwave oven to get iron hot enough to melt and is using it in his latest video to cast real, working tools with it.

In the past, [Shake the Future] has made a few other things with this setup like an aluminum pencil with a graphite core. This time, though, he’s stepping up the complexity a bit with a working tool. He’s decided to build a miniature bench vice, which uses a screw to move the jaws. He didn’t cast the screw, instead using a standard size screw and nut, but did cast the two other parts of the vice. He first 3D prints the parts in order to make a mold that will withstand the high temperatures of the molten metal. With the mold made he can heat up the iron in the microwave and then pour it, and then with some finish work he has a working tool on his hands.

A microwave isn’t the only kitchen appliance [Shake the Future] has repurposed for his small metalworking shop. He also uses a standard air fryer in order to dry parts quickly. He works almost entirely from the balcony of his apartment so he needs to keep his neighbors in mind while working, and occasionally goes to a nearby parking garage when he has to do something noisy. It’s impressive to see what can be built in such a small space, though. For some of his other work be sure to check out how he makes the crucibles meant for his microwave.

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FPGA Brings Antique Processor To Life

November 14, 2025 by 12 Comments

For the retro gaming enthusiast, nothing beats original hardware. The feel of the controllers and the exact timing of the original, non-emulated software provide a certain experience that’s difficult or impossible to replicate otherwise. To that end, [bit-hack] wanted to play the original EGA, 16-color version of The Secret of Monkey Island in a way that faithfully recreated the original and came up with this FPGA-based PC with a real NEC V20 powering it all.

The early 90s-style build is based on a low-power version of the V20 called the V20HL which makes it much easier to interface with a modern 3.3 V FPGA compared to the original 5 V chip. It’s still an IBM XT compatible PC though, with the FPGA tying together the retro processor to a 1 MB RAM module, a micro SD slot that acts as a hard disk drive, a digital-to-analog audio converter, and of course the PS/2 keyboard and mouse and VGA port. The mouse was one of the bigger challenges for [bit-hack] as original XT PCs of this era would have used a serial port instead.

With a custom PCB housed in a acrylic case, [bit-hack] has a modern looking recreation of an XT PC running an original processor and capable of using all of the period-correct peripherals that would have been used to play Monkey Island when it was first released.

FPGAs enable a ton of retrocomputing projects across a wide swath of platforms, and if you’re looking to get started the MiSTer FPGA project is a great resource.

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3D Printing A Piano Action

November 13, 2025 by 14 Comments

Part of the reason there are always free pianos on your digital classifieds listing of choice is that, at least economically speaking, a piano is less of a musical instrument and more of a complicated machine that can and will wear out (not to mention the physical difficulty of actually moving one). Once a piano reaches that point, whether through age, use, or neglect, at that point it’s to intents and purposes worthless. But still, they’re essentially just machines. [Toast] figured that, since 3D printers not only can print all kinds of other machines and musical instruments alike, he would take a stab at combining these two and made his own 3D printed piano.

A piano’s action is the mechanical linkage between the keys and the strings of the piano themselves. Over many hundreds of years this has developed into a complicated series of levers which not only rapidly strike strings when a key is pressed, but also mute the strings while the key is not being pressed and strike the strings in a way that the hammer won’t be pressed into the strings if the player leaves their finger on a key. Rather than try to recreate all of this in meticulous detail, [Toast] has swapped out the strings for a series of tubes which, unlike strings, do not much change their musical behavior if the hammer remains on the tube after being struck. This greatly simplifies the action (and cost) of his miniature piano.

The piano works by positioning hammers above these tubes, which strike downwards when a musician depresses the keys. Rubber bands return the hammers to their upright positions after the key is lifted. The instrument went through a few stages of design as well where [Toast] refined the size and shape of the tubes as well as improved the way by which the hammers are attached to the keys.

Is it still a piano if it has pipes instead of strings? Perhaps, but at the very least we can all agree that he’s built a working keyboard action capable of producing music, if not an outright definitionally-accurate piano. It’s an interesting build that we hope to see more iterations of in the future, if not to build a more functionally accurate 3D printed piano action then to see what is possible from a 3D printer in the piano space. Despite their complexity and weight, pianos are a fundamental and popular instrument in the Western music tradition and we’ve seen many interesting builds around them like this modern player piano built with a series of solenoids. Continue reading “3D Printing A Piano Action” →

2025 Component Abuse Challenge: Relay Used As Guitar Pickup

November 13, 2025 by 16 Comments

We’ve all built projects that are a rats’ nest of wiring and feature creep, but the best projects in the end are usually those that use a simple solution to elegantly solve a problem. [Kauz] had been thinking about a unique type of electric guitar pickup for a while and rather than purchase an expensive option or build a complex microcontroller-based system he found his elegant solution in the form of a common electronic component.

The core of this idea is that guitar pickups are essentially coils of wire, and are surprisingly similar to the coils of wire found in electromechanical relays. [Kauz] has used six small relays, left them unmodified, and then built an amplifier circuit for each to allow the vibrations of the guitar strings to resonate in the relay coils, eventually producing a sound. Not only do the relays work perfectly well as pickups, but [Kauz] also created a mixing board that allows the six relays to be combined into two channels, allowing for options like stereo sound for different strings directly out of the guitar or for different effects to be applied to different strings.

The build also allows for some interesting options in future versions as well. [Kauz]’s plans are eventually to build this into an instrument which can output polyphonic MIDI signals, where various strings can behave as different instruments. In theory, with six circuits six different instruments can be produced, and we’re excited to see what the next versions will look and sound like. In the meantime, be sure to check out some other guitar pickups we’ve seen that use even simpler parts found lying around the workbench.

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Pi Compute Modules Make For Compact Cluster

November 12, 2025 by 22 Comments

Raspberry Pi clusters have been a favorite project of homelabbers and distributed computing enthusiasts since the platform first launched over a decade ago, and for good reason. For an extremely low price this hardware makes it possible to experiment with parallel computing — something that otherwise isn’t easily accessible without lots of time, money, and hardware. This is even more true with the compute modules, as their size and cost makes some staggering builds possible like this cluster sporting 112 GB of RAM.

The project is based on the NanoCluster, a board that can hold seven compute modules in a form factor which, as [Christian] describes it, is about the size of a coffee mug. That means not only does it have a fairly staggering amount of RAM but also 28 processor cores to work with. Putting the hardware together is the easy part, though; [Christian] wanted to find the absolute easiest way of managing a system like this and decided on gitops, which is a method of maintaining a server where the desired system state is stored in Git, and automation continuously ensures the running environment on the hardware matches what’s in the repository.

For this cluster, it means that the nodes themselves can be swapped in and out, with new nodes automatically receiving instructions and then configuring themselves automatically. Updates and changes made on Git are pushed to the nodes automatically as well and there’s not much that needs to be done manually at all. In much the same way that immutable Linux distributions move all of the hassle of administering a system to something like a config file, tools like gitops do the same for servers and clusters like this, and it’s worth checking out [Christian]’s project to get an idea of just how straightforward it can be now.

DIY Pinball Machine Uses Every Skill

November 1, 2025 by 6 Comments

Pinball machines have something for everyone. They’re engaging, fast-paced games available in a variety of sizes and difficulties, and legend has it that they can be played even while deaf and blind. Wizardry aside, pinball machines have a lot to offer those of us around here as well, as they’re a complex mix of analog and digital components, games, computers, and artistry. [Daniele Tartaglia] is showing off every one of his skills to build a tabletop pinball machine completely from the ground up.

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