Pulling Back The Veil, Practically

May 31, 2025 by Elliot Williams 15 Comments

In a marvelous college lecture in front of a class of engineering students, V. Hunter Adams professed his love for embedded engineering, but he might as well have been singing the songs of our people – the hackers. If you occasionally feel the need to explain to people why you do what you do, at fancy cocktail parties or something, this talk is great food for thought. It’s about as good a “Why We Hack” as I’ve ever seen.

Among the zingers, “projects are filter removers” stuck out. When you go through life, there are a lot of things that you kinda understand. Or maybe you’ve not even gotten around to thinking about whether you understand them or not, and just take them for granted. Life would all simply be too complicated if you took it all sufficiently seriously. Birdsong, Bluetooth, the sun in the sky, the friction of your car’s tire on various surfaces. These are all incredibly deep subjects, when you start to peel back the layers.

And Hunter’s point is that if you are working on a project that involves USB, your success or failure depends on understanding USB. There’s no room for filters here – the illusion that it “just works” often comes crashing down until you learn enough to make it work. Some of his students are doing projects cooperatively with the ornithology department, classifying and creating birdsong. Did you know that birds do this elaborate frequency modulation thing when they sing? Once you hear it, you know, and you hear it ever more.

So we agree with Hunter. Dive into a project because you want to get the project done, sure, but pick the project because it’s a corner of the world that you’d like to shine light into, to remove the filters of “I think I basically understand that”. When you get it working, you’ll know that you really do. Hacking your way to enlightenment? We’ve heard crazier things.

A weather forecast is shown on a blue monochrome cathode ray tube display. It is displaying current conditions, and displays a “The Weather Channel” graphic in the top left corner.

A CRT Display For Retro Weather Forecasting

May 31, 2025 by Aaron Beckendorf 16 Comments

It would be hard to find any electronics still in production which use CRT displays, but for some inscrutable reason it’s easy to find cheap 4-inch CRTs on AliExpress. Not that we’re complaining, of course. Especially when they get picked up for projects like this Retro CRT Weather Display from [Conrad Farnsworth], which recreates the interface of The Weather Channel’s WeatherStar 4000+ in a suitably 90s-styled format.

The CRT itself takes up most of the space in the enclosure, with the control electronics situated in the base behind the display driver. A Raspberry Pi Zero W provides the necessary processing power, and connects to the CRT through its composite video output.

A custom PCB plugs into the GPIO header on the Raspberry Pi and provides some additional features, such as a rotary encoder for volume and brightness display, a control button, a serial UART interface, and a speaker driver. The design still has one or two caveats: it’s designed to powered by USB, but [Conrad] notes that it draws more current than USB 2.0 can provide, though USB-C should be able to keep up.

On the software side, a Python program displays a cycle of three slides: local weather, regional weather, and a radar display. For the local and regional weather display graphics, [Conrad] created a static background image containing most of the graphics, and the program only generated the dynamic components. For the radar display, the regional map’s outlines come from Natural Earth, and a Python program overlays radar data on them.

We’ve seen other attempts at recreating the unique style of the WeatherStar system, but nothing quite beats the real thing.
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Making A Treadmill Into A 3D Printer

May 31, 2025 by Lewin Day 7 Comments

A treadmill-style bed can be a great addition to a 3D printer. It allows prints to be shifted out of the build volume as printing continues, greatly increasing the size and flexibility of what you can print. But [Ivan Miranda] and [Jón Schone] had a question. Instead of making a treadmill to suit a 3D printer, what if you just built a 3D printer on top of a full-size treadmill?

The duo sourced a piece of real gym equipment for this build. They then set about building a large-scale 3D printer on top of this platform. The linear rails were first mounted on to the treadmill’s frame, followed by a gantry for the print head itself and mounts for the necessary stepper motors. The printer also gained a custom extra-large extruder to ensure a satisfactory print speed that was suitable for the scale of the machine. From there, it was largely a case of fitting modules and running cables to complete the printer.

Soon enough, the machine was printing hot plastic on the treadmill surface, thereby greatly expanding the usable print volume. It’s a little tricky to wrap your head around at first, but when you see it in action, it’s easy to see the utility of a build like this, particularly at large scale. [Ivan] demonstrated this by printing a massive girder over two meters long.

We started seeing attempts at building a belt-equipped “infinite build volume” printer back in 2017, and it took awhile before the concept matured enough to be practical. Even today, they remain fairly uncommon.

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Mark Setrakian and Adam Savage investigate a massive prop hand

17 Year Old Hellboy II Prop Still Amazes

May 30, 2025 by Heidi Ulrich 7 Comments

The AI effects we know these days were once preceded by CGI, and those were once preceded by true hand-built physical props. If that makes you think of Muppets, this video will change your mind. In a behind-the-scenes look with [Adam Savage], effects designer [Mark Setrakian] reveals the full animatronic glory of Mr. Wink’s mechanical fist from Hellboy II: The Golden Army (2008) – and this beast still flexes.

Most of this arm was actually made in 2003, when 3D printing was very different than what we think of today. Printed on a Stratasys Titan – think: large refrigerator-sized machine, expensive as sin – the parts were then hand-textured with a Dremel for that war-scarred, brutalist feel. This wasn’t just basic animatronics for set dressing. This was a fully actuated prop with servo-driven finger joints, a retractable chain weapon, and bevel-geared mechanisms that scream mechanical craftsmanship.

Each finger is individually designed. The chain reel: powered by a DeWalt drill motor and custom bevel gear assembly. Every department: sculptors, CAD modelers, machinists, contributed to this hybrid of analog and digital magic. Props like this are becoming unicorns.

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White LED Turning Purple: Analyzing A Phosphor Failure

May 30, 2025 by Maya Posch 32 Comments

White LED bulbs are commonplace in households by now, mostly due to their low power usage and high reliability. Crank up the light output enough and you do however get high temperatures and corresponding interesting failure modes. An example is the one demonstrated by the [electronupdate] channel on YouTube with a Philips MR16 LED spot that had developed a distinct purple light output.

The crumbling phosphor coating on top of the now exposed LEDs. (Credit: electronupdate, YouTube)

After popping off the front to expose the PCB with the LED packages, the fault seemed to be due to the phosphor on one of the four LEDs flaking off, exposing the individual 405 nm LEDs underneath. Generally, white LEDs are just UV or 405 nm (‘blue’) LEDs that have a phosphor coating on top that converts the emitted wavelength into broad band visible (white) or another specific wavelength, so this failure mode makes perfect sense.

After putting the PCB under a microscope and having a look at the failed and the other LED packages the crumbled phosphor on not just the one package became obvious, as the remaining three showed clear cracks in the phosphor coating. Whether due to the heat in these high-intensity spot lamps or just age, clearly over time these white LED packages become just bare LEDs without the phosphor coating. Ideally you could dab on some fresh phosphor, but likely the fix is to replace these LED packages every few years until the power supply in the bulb gives up the ghost.

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You Wouldn’t Download A Skateboard?

May 30, 2025 by Fenix Guthrie 9 Comments

At the end of the day, a skateboard boils down to a plank of wood with some wheels. They are wonderfully simple and fun and cheap modes of transportation. But this is Hackaday, so we are not here to talk about any normal skateboard, but one you can download and print. [megalog_’s] Skateboard MK2 is made almost entirely of 3D printed plastic, save some nuts and bolts.

The board’s four piece deck comes in at a modest 55cm length and features a rather stylish hexagonal pattern for grip. While you could presumably bring your own trucks, 3D printable ones are provided as well. The pieces bolt together to create a fairly strong deck with the option to make a rather stylish two tone print if you have the printer for it. Where the pieces meet is also the location of the truck mounting, further increasing the board’s strength. The weakest point is where the tail meets the main deck, which if pressed down to wheelie or ollie, the print breaks apart at the layer lines.

While you might be able to bring your own trucks, all be it with some modification to the deck, [megalog] also provided models for those as well. Not only were the bushings made of flexible TPE filament, but the outer wheel tire is too. It’s a little strange to see a wheel tire combo on a skateboard, when they are traditionally over moulded plastic with enough tire that you would be forgiven for thinking there is no wheel. While some reported using the more traditional threaded rod, the trucks used a metal rod with shaft collars to attach the wheels.

This is a neatly executed skateboard build with a well thought out design. Let us know in the comments if you will (or have) made one yourself! While you’re at it, maybe cast your own resin wheels for it!

Tidy LED Matrix Displays GIFs On Demand

May 30, 2025 by Lewin Day 4 Comments

When it comes to LED matrixes, building one is just the first step. Then you have to decide what to display on it. [panjanek] came up with a relatively flexible answer to this question, building an RGB LED matrix that can display the GIFs of your choice.

The web interface accepts GIFs for display.

[panjanek] grabbed WS2812B addressable LEDs for this project, assembling them into a 32 x 32 matrix that fits perfectly inside an off-the-shelf Ikea picture frame. The matrix is hooked up to an ESP8266 microcontroller, which acts as the brains of the operation. The WiFi-enabled microcontroller hosts its own web interface, with which the project can be controlled. Upon opening the page, it’s possible to upload a GIF file that will be displayed as an animation on the matrix itself. It’s also possible to stream UDP packets of bitmap data to the device to send real-time animations over a network.

It’s a neat build, and one that answers any questions of what you might display on your LED matrix when you’re finished assembling it. Code is on Github if you fancy implementing the GIF features in your own work. We’ve featured some unexpected LED matrix builds of late, like this innovative device for the M.2 slot. Meanwhile, if you’re cooking up your own creative LED builds, don’t hesitate to let us know on the tipsline!