Schematic diagram of the touch-sensitive skin. (Credit: Haofeng Chen et al., ArXiv, 2026)
Hypoesthesia, more commonly referred to as numbness, is one of the more distressing ailments that can affect us humans, primarily because it reminds us of just how much we rely on our sensation of touch in daily life. From experiencing the world around us, handling objects, noticing when you just bumped into that side table again and the comforting hug of a fellow human being, touch is perhaps the most important of our senses.
One of the fun aspects of open source software is that you can often find so many libraries and tools that implement the functionality you need, but ease of use for e.g. artists is often not a priority. This is where [Edin Spiegel] ‘s annoyances with photogrammetry tools led him down to the path of creating the Simple Photogrammetry GUI project, which is basically what it says on the tin.
In an associated video its development and use is demonstrated, combining tools like Colmap, OpenMVS, mvs-texturing, pymeshlab, brush and PoissonRecon to implement both photogrammetry and gaussian splatting to turn those photos into a not too shabby mesh along with realistic textures.
The GUI uses the Flutter GUI kit, so Linux support is still somewhat sketchy, but should work in this new release of this GUI wrapper. The author is asking for people to test this GUI and report any issues found so that they can be addressed.
From a quick glance at the project and the comments to the video it seems quite useful for anyone who wants to get started quickly with photogrammetry. One niggle is perhaps that it relies on processing using CUDA, with a much slower fallback to CPU processing if you do not happen to have an Nvidia-blessed GPU installed. Of course this is one of those universal issues in a world where theoretically everyone should be using OpenCL already.
In addition to the build instructions you can also download an AppImage for Linux and compiled binaries for Windows to theoretically get started as fast as your internet connection allows. Interestingly, the AppImage is well over a GB in size, whereas the Windows ZIP file is just 207 MB for the v1.1.5 release, so take that into account.
Not the prettiest ruby, for sure. (Credit: Gems of Science, YouTube)
Sapphires and rubies aren’t just pretty, they also got a range of practical uses. This makes it even more useful to be able to make them at home for obviously completely innocent experiments. Cue [Gems of Science] and his attempts to make good-looking rubies, without resorting to the brute-force laser blasting approach that [Styropyro] previously used to create murky-looking gems.
That basic method used involves blasting aluminium oxide with a laser, which results in a container full of what are technically gems, but – as the image on the right makes clear – not exactly the prettiest or easiest to shine up. Much of the problem here is that these are hollow geodes composed of countless tiny crystals instead of solid singular crystals.
Although there are commercial ways to fairly easily create large crystals from a small seed crystal, none of these lend themselves to a DIY hobbyist with just a garage to muck about in. This leaves one alternative: the flux method. Rather than melting the material that will be grown onto the seed crystal, this flux crystal growth method uses a solvent (flux) and temperatures that a home kiln can achieve.
These rubies may be small, but are very shiny. (Credit: Gems of Science, YouTube)
Of note here is also that it’s the addition of Cr3+ ions into the base Al2O3 matrix that makes a ruby into a ruby, by giving it its red glow. In order to grow crystals this way you need to pick not only a suitable solvent, but also use a crucible that doesn’t want to become part of said crystal. Unfortunately a platinum crucible runs into the thousands of USD, but a graphite crucible should do if you keep oxygen away from it.
For the flux molybdenum oxide was used, mixed with chromium oxide and aluminium oxide to provide the ingredients for crystal growth. Unfortunately added charcoal interfered with the molybdenum, ruining that batch. This led to trying out more crucible types to find a recipe that worked, thereby finding out that an ‘alumina’ crucible also contained silica, which poisons the reaction, resulting in only tiny ruby crystals.
Ultimately pure alumina crucibles seemed to work great, until they began to shatter en masse, resulting in pained wallet noises and the purchases of some pre-loved platinum crucibles. This worked really well, but now the flux was evaporating too quickly to enable large crystal growth, thus requiring additives to stabilize it. Along with temperature cycling to induce the growth of larger crystals, this finally generated some solid results. After a first batch of smaller rubies, next up larger ones of up to 10 mm were grown.
While cutting one of these large rubies to set into a ring it was clear that it was still rather flawed, with pockets of flux captured into the crystal, but with the basic method now more or less dialed in it should be possible to address these small flaws as well.
Using the special pens to remove the wax coating on the template. (Credit: Old Typerwriters and Calculators, YouTube)
Document duplication has been a highly desirable feature long before medieval monks slaved over yet another illuminated manuscript by flickering candlelight. Fortunately, one part of the Industrial Revolution was the invention of machines like Cyclostyle copying machines, which covered a range of manual and automated devices. One such crank-powered device from 1890 is demonstrated in this video.
The Cyclostyle and neo-Cyclostyle copying system was quite simple yet elegant: by removing the wax coating on a special piece of paper, ink from a screen-printing system could be pressed through the resulting template, and allow for repeat copies to be made.
With the machine demonstrated in the video, the ink is applied to the top rollers, with the lower roller inking itself on them during the retraction cycle, before applying the fresh ink to the screen on the cycle following the insertion of a fresh piece of paper to print on. With this method, many copies of the design on the waxed template could be made before it had to be replaced, which would have saved countless hours of work by artists.
After the machine in the video, more advanced designs were developed, some of which we covered previously. These would automate more parts of the process, making it faster and more precise, before being replaced by newer technologies.
It’s arguably adult-sized. (Credit: Sam Barker, YouTube)
A staple of old movies featuring railways, many handcars – also called pump trolleys or pump cars – feature the characteristic seesawing beam. Requiring at least two people, the motion of this beam is subsequently converted into the rotating motion of the wheels, propelling it at a leisurely pace across the tracks. As a fun and yet functional mechanical contraption it also makes for an entertaining 3D printable project, which is what [Sam Barker] and [Tom] did.
You can find the entire project over at Printables if you are feeling the itch as well, though as of writing details on the required bolts and shafts are still pending.
Since the entire assembly had to be lugged over to the Open Sauce event in the US, they had to design it to be small enough to fit into check-in luggage and easy enough to reassemble in a hotel room. Naturally this put some constraints on the full size of the contraption, with it omitting compatibility with standard gauge railways and also being decidedly fun-sized.
That said, it seems to have left an impression on the folk over at Open Sauce, and it’s hard to argue with the sheer fun factor of such a co-op mode of transportation. Even if bicycle-style handcars are more popular these days, especially for tourist purposes, the old seesaw-style has that certain charm to it.
After previously putting a very basic version of Minecraft on the Game Boy Color, [Tobi] decided to have some fun and port that version also to the Super Nintendo (SNES), just to see what would happen with its more powerful hardware. Even without using an add-on chip like the Super FX 3D chip that made games like Star Fox and Doom possible with its 3D-rendered geometry, the basic SNES hardware can already provide a serviceable Minecraft experience.
You can download the SFC file here, featuring a starting world in which you can do all the usual Minecraft-ing shenanigans, like world destruction and construction. Unsurprisingly the game’s resolution is much higher than on the GBC, though the brief glimpse [Tobi] shows of Minecraft on the Game Boy Advance (GBA) with its proper 3D-rendering hardware are leaps ahead of what the basic SNES can do.
This of course raises the question of what Minecraft on the SNES could look like once you add the Super FX or similar 3D accelerator chips for the SNES into the mix. Rather than just being limited to sprite-based graphics and transformations, suddenly you can use real polygons.
A time-honored tradition in the electronics repair business is to make many into one, specifically a stack of broken devices into one that works. So too with a triplet of heavily corroded and bug-infested WiiMote controllers that [eWastelander] dug out of a box of e-waste. After suffering abuse like leaving in leaky alkaline cells, bugs and general corrosion the task was to see whether at least one working WiiMote could be assembled from these three. (Video, embedded below.)
Adding to the fun was that the PCBs in these WiiMotes spanned at least two hardware revisions, and on one board the battery corrosion had caused an IC to fall off. After an initial assessment, neutralizing the battery acid and a deep clean of all the disassembled parts, it was time to give it a shot at reassembly into something resembling a Wii controller you could use and even want to touch without washing your hands afterwards.
Ultimately at least one working WiiMote was put together, with still an open question whether the remaining two units in much worse conditions could be revived in some way. An interesting idea here is to use the WiiMote shells for a custom OpenMote board, which replaces the guts with an ESP32-S3-based system for more general non-Wii things around the house.
