Clear Resin Casting Replicates Old Acrylic For Selectric Repair

March 10, 2026 by 22 Comments

IBM Selectric typewriters have a lot of unique parts that can be tricky to source, but one we didn’t think of was the clear acrylic(?) dust covers, that are apparently very hard to find in good shape. [Eric Strebel] has a few Selectrics that all have issues with these parts. While you could come close to recreating this piece with acrylic sheeting carefully bent to match the original shape, [Eric] has a different hammer to try in a new video: replicating it with a resin casting.

He uses de-gassed tin-cure silicone to create a mold for the original, with a bit of 3D printed PLA and foam board to hold the silicone to create the mold. That’s done in two steps to create a two-part mold, which is separated and cleaned before the resin goes in. The original part is actually a smoky plastic, rather than fully clear, but [Eric] is able to match it perfectly using a colourant in his clear ̶e̶p̶o̶x̶y̶ polyurethane resin. The resin is put into the mold with a simple gravity pour, though he does have a vibrator on it to help it flow. Curing is done under heat and pressure– 60 PSI. The results are amazing; once he adds a touch of paint to match the black finish on one face of the original, it’s very difficult to tell [Eric]’s casting from his master piece, except that the cast replicas are in better shape.

This particular part works very well for casting and not much else. While you could match the large curve by heat-bending a piece of smoky acrylic, there are lips along the edges of the part that would be tricky to reproduce. [Eric] also needed several, for his multiple typewriters, and this method is very efficient at producing multiple units since the mold is reusable.

While you might not have an IBM Selectric that needs a dust cover, this technique is equally applicable to all sorts of clear shapes. If you’re new to resin casting, we have a handy guide to replicating plastic parts to get you started in this kind of work. It’s not just large parts that can be replicated: you can even copy phonograph records, such is the fidelity of resin casting.

Continue reading “Clear Resin Casting Replicates Old Acrylic For Selectric Repair” →

There Are No LEDs Around The Face Of This Clock

March 10, 2026 by 6 Comments

This unusual clock by [Moritz v. Sivers] looks like a holographic dial surrounded by an LED ring, but that turns out to not be the case. What appears to be a ring of LEDs is in fact a second hologram. There are LEDs but they are tucked out of the way, and not directly visible. The result is a very unusual clock that really isn’t what it appears to be.

The face of the clock is a reflection hologram of a numbered spiral that serves as a dial. A single LED – the only one visibly mounted – illuminates this hologram from the front in order to produce the sort of holographic image most of us are familiar with, creating a sense of depth.

The lights around the circumference are another matter. What looks like a ring of LEDs serving as clock hands is actually a transmission hologram made of sixty separate exposures. By illuminating this hologram at just the right angle with LEDs (which are mounted behind the visible area), it is possible to selectively address each of those sixty exposures. The result is something that really looks like there are lit LEDs where there are in fact none.

[Moritz] actually made two clocks in this fashion. The larger green one shown here, and a smaller red version which makes some of the operating principles a bit more obvious on account of its simpler construction.

If it all sounds a bit wild or you would like to see it in action, check out the video (embedded below) which not only showcases the entire operation and assembly but also demonstrates the depth of planning and careful execution that goes into multi-exposure of a holographic plate.

[Moritz v. Sivers] is no stranger to making unusual clocks. In fact, this analog holographic clock is a direct successor to his holographic 7-segment display clock. And don’t miss the caustic clock, nor his lenticular clock.

Continue reading “There Are No LEDs Around The Face Of This Clock” →

Turning A GDB Coredump Debug Session Into A Murder Mystery

March 10, 2026 by 2 Comments

Debugging an application crash can oftentimes feel like you’re an intrepid detective in a grimy noir detective story, tasked with figuring out the sordid details behind an ugly crime. Slogging through scarce clues and vapid hints, you find yourself down in the dumps, contemplating the deeper meaning of life and  the true nature of man, before hitting that eureka moment and cracking the case. One might say that this makes for a good game idea, and [Jonathan] would agree with that notion, thus creating the Fatal Core Dump game.

Details can be found in the (spoiler-rich) blog post on how the game was conceived and implemented. The premise of the game is that of an inexplicable airlock failure on an asteroid mining station, with you being the engineer tasked to figure out whether it was ‘just a glitch’ or that something more sinister was afoot. Although an RPG-style game was also considered, ultimately that proved to be a massive challenge with RPG Maker, resulting in this more barebones game, making it arguably more realistic.

Suffice it to say that this game is not designed to be a cheap copy of real debugging, but the real deal. You’re expected to be very comfortable with C, GDB, core dump analysis, x86_64 ASM, Linux binary runtime details and more. At the end you should be able to tell whether it was just a silly mistake made by an under-caffeinated developer years prior, or a malicious attack that exploited or introduced some weakness in the code.

If you want to have a poke at the code behind the game, perhaps to feel inspired to make your own take on this genre, you can take a look at the GitHub project.

Blood Tests Could Provide Early Warning Of Alzheimers Disease

March 10, 2026 by 2 Comments

Alzheimer’s disease remains a frustratingly difficult condition to manage for the millions of patients affected worldwide and their families. The cause of the disease is still not properly understood, and by the time memory loss and cognitive decline become apparent, the underlying brain pathology has often been quietly building for decades.

Soon, though it may be possible to diagnose impending Alzheimer’s disease ahead of time, before symptoms have taken hold. New research suggests this could be achieved through a simple blood draw, providing clinicians and patients precious time to manage the condition and plan ahead. Continue reading “Blood Tests Could Provide Early Warning Of Alzheimers Disease” →

Power Control For A Busy Workbench

March 10, 2026 by 30 Comments

Who among us does not have a plethora of mains-powered devices on their workbench, and a consequent mess of power strips to run them all? [Jeroen Brinkman] made his more controllable with a multi-way switch box.

At first sight it’s a bank of toggle switches, one for each socket. But this is far more than a wiring job, because of course there are a couple of microcontrollers involved, and each of those switches ultimately controls a relay. There are also status LEDs for each socket, and a master switch to bring them all down. Arduino code is provided, so you can build one too if you want to.

We like the idea of a handy power strip controller, and especially the master switch with the inherent state memory provided by the switches. This could find a home on a Hackaday bench, and we suspect on many others too. It’s by no means the first power strip with brains we’ve seen, but most others have been aimed at the home instead.

The “Tin Blimp” Was A Neither Tin Nor A Blimp: The Detroit ZMC-2 Story

March 10, 2026 by 22 Comments
That fireball was LZ37. Nobody wanted to see repeats post-war.
Image: “The great exploit of lieutenant Warnefort 1916 England” by Gordon Crosby, public domain.

After all the crashing and burning of Imperial Germany’s Zeppelins in the later part of WWI – once the Brits managed to build interceptors that could hit their lofty altitude, and figured out the trick of using incendiary rounds to set off the hydrogen lift gas – there was a certain desire in airship circles to avoid fires. In the USA, that mostly took the form of replacing hydrogen with helium. Sure, it didn’t lift quite as well, but it also didn’t explode.

Still, supplies of helium were– and are– very much limited, and at least on a rigid Zeppelin, the hydrogen wasn’t even the most flammable part. As has become widely known, thanks in large part to the Mythbusters episode about the Hindenburg disaster, the doped cotton skin in use in those days was more flammable than some firestarters you can buy these days.

That’s a problem, because, as came up in the comments of our last airship article, rigid airships beat blimps largely on Rule of Cool. Who invented the blimp? Well, arguably it was Henri Griffard with his steam-driven balloon in 1857, but not many people have ever heard his name. Who invented the rigid airship? You know his name: Ferdinand Adolf Heinrich August Graf von Zeppelin. No relation. Probably. Well, admittedly most people don’t know the full name, but Count Zeppelin is still practically a household name over a century after his death. His invention was just that much cooler.

That unavoidable draw of coolness led to the Detroit Airship Company and their amazing tin blimp. The idea was the brainchild of a man named Ralph Upton, and is startling in its simplicity: why not take the all-metal, monocoque design that was just then being so successfully applied to heavier-than-air flight, and use it to build an airship? Continue reading “The “Tin Blimp” Was A Neither Tin Nor A Blimp: The Detroit ZMC-2 Story” →

Arduino’s New AI-Centric Board Is The VENTUNO Q

March 10, 2026 by 33 Comments

There have been many questions about what direction Arduino would take after being bought by Qualcomm. Now it would seem that we’re getting a clearer picture. Perhaps unsurprisingly the answer appears to be ‘AI’, with the new Arduino VENTUNO Q SBC being advertised as ‘democratizing AI’ in the Qualcomm press release, although it also references robotics.

This new board is based around the Dragonwing IQ-8275 SoC along with an STM32H5F5 MCU, making it somewhat of a beefier brother of the previously covered Arduino Uno Q, which also offers an SoC/MCU hybrid solution. On the product page we can see the overall specifications for this new board, where the release date is specified as ‘soon’.

Its IQ-8275 SoC is part of Qualcomm’s IQ8 series, with eight 2.35 GHz ARM cores and an Adreno 623 GPU, paired with 16 GB of LPDDR5. The Cortex M33-based STM32H5F5 MCU comes with its own 4 MB of Flash and 1.5 MB of RAM, all on a board that’s significantly larger than the Uno Q and isn’t crippled by a single USB-C port as SoC I/O.

Although clearly more aimed at industrial and automation applications than the solution-in-search-of-a-problem Uno Q board, it remains to be seen whether this board will catch on with Arduino fans, or whether Qualcomm’s goal is more to break into whole new markets under the Arduino brand.