Desk Top Peltier-Powered Cloud Chamber Uses Desktop Parts

August 9, 2025 by 6 Comments

There was a time when making a cloud chamber with dry ice and alcohol was one of those ‘rite of passage’ type science projects every nerdy child did. That time may or may not be passed, but we doubt many children are making cloud chambers quite like [Curious Scientist]’s 20 cm x 20 cm Peltier-powered desktop unit.

The dimensions were dictated by the size of the off-the-shelf display case which serves as the chamber, but conveniently enough also allows emplacement of four TEC2-19006 Peltier cooling modules. These are actually “stacked” modules, containing two thermoelectric elements in series — a good thing, since the heat delta required to make a cloud chamber is too great for a single element. Using a single-piece two stage module simplifies the build considerably compared to stacking elements manually.

To carry away all that heat, [Curious Scientist] first tried heatpipe-based CPU coolers, but moved on to CPU water blocks for a quieter, more efficient solution. Using desktop coolers means almost every part here is off the shelf, and it all combines to work as well as we remember the dry-ice version. Like that childhood experiment, there doesn’t seem to be any provision for recycling the condensed alcohol, so eventually the machine will peter out after enough vapor is condensed.

This style of detector isn’t terribly sensitive and so needs to be “seeded” with spicy rocks to see anything interesting, unless an external electric field is applied to encourage nucleation around weaker ion trails. Right now [Curious Scientist] is doing that by rubbing the glass with microfiber to add some static electricity, but if there’s another version, it will have a more hands-off solution.

We’ve seen Peltier-Powered cloud chambers before (albeit without PC parts), but the “dry ice and alcohol” hack is still a going concern. If even that’s too much effort, you could just go make a cup of tea, and watch very, very carefully.

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2025 One Hertz Challenge: Estimating Pi With An Arduino Nano R4

August 9, 2025 by 10 Comments

Humanity pretty much has Pi figured out at this point. We’ve calculated it many times over and are confident about what it is down to many, many decimal places. However, if you fancy estimating it with some electronic assistance, you might find this project from [Roni Bandini] interesting.

[Roni] programmed an Arduino Nano R4 to estimate Pi using the Monte Carlo method. For this specific case, it involves drawing a circle inscribed inside a square. Points are then randomly scattered inside the square, and checked to see if they lie inside or outside the circle based on their position and distance of the circle’s outline from the center point of the square. By taking the ratio of the points inside the circle to the total number of points, you get an approximation of the ratio of the square and circle’s areas, which is equal to Pi/4. Thus, multiply the ratio by 4, and you’ve got your approximation of Pi.

[Roni] coded a program to run the Monte Carlo simulation on the Arduino Nano R4, taking advantage of the mathematical benefits of its onboard Floating Point Unit. It generates 100 new samples for the Monte Carlo approximation every second, improving the estimation of pi as it goes. It then displays the result on a 7-segment display, and beeps as it goes. [Roni] readily admits the project is a little too close in appearance to a classic Hollywood bomb.

We’ve seen some other neat Pi-calculating projects before, too.

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The Kilopixel Display

August 9, 2025 by 7 Comments

Despite the availability of ready-made displays never being better, there are still some hardy experimenters who take on the challenge of making their own. In [Ben Holmen]’s case the display he built is somewhat unusual and not the most practical, but for us a giant-sized wooden kilopixel display is exactly what the world needs.

It’s a kilopixel display because it has a resolution of 40 by 25 pixels, and it takes the form of a rack of wooden cubes, each of which can be turned by a tool on a gantry to expose either a black or a white side. It’s very slow indeed — he has an over nine hour long video of it in operation — but it is an effective device.

His write-up goes into great detail about the steps taken in its design, starting with spherical pixels rotated by a LEGO wheel and progressing to cubes poked at their corner to rotate. The pusher in this case is a hot glue stick, for the required flexibility. For practicality we’re reminded of this serial oil-and-water display.

The whole thing is online, and if you want you can submit your own images for it to draw. Whether a Wrencher in 25 pixel resolution has enough detail, we’ll leave to you.

A Love Letter To Prototype Zero

August 9, 2025 by 11 Comments

An old friend of mine at my hackerspace introduced me to the concept of Prototype Zero: The Version that Even Your Own Sweet Mother Isn’t Allowed to See. The idea is that when you’re building something truly new, or even just new to you, your first take will almost always be ugly, and nothing will work the way it will by the time you make your second one. But it’s also important to the exercise that you see it all the way through to the end if you can.

I’m reminded of this after seeing a marvelous video by [Japhy Riddle] where he discusses his Prototype Zero of the Tape-Speed Keyboard. About halfway through the video he says that he would have done it totally differently if he knew then what he knows now: the hallmark of Prototype Zero. Yet he finishes it up, warts and all, documents it, and plays around with all of its possibilities. (Documenting it publicly isn’t part of the Prototype Zero method.)

I don’t think that [Japhy] is going to make a Prototype 1.0 out of this project, but I could be wrong; he seems to be content with having scratched the variable-speed tape itch. But if he did want to, he’s learned all of the gotchas on the engineering side, and found out exactly what such an instrument is capable of. And this loops back to the importance of getting Prototype Zero finished. You may have learned all of the tricks necessary to build the thing even before you’ve put the last screw in, but it’s when you actually have the thing in your hands to explore that you get the ideas for refinement that you simply can’t think up when it’s still just a concept.

Don’t be afraid to make your prototype quick and dirty, because if it ends up too dirty, you can just call it Prototype Zero. But don’t be tempted by the siren’s song of the 80% finished prototype either. Exploring putting Prototype Zero into use is its real purpose.

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3D Printing A Giant Beyblade Arena

August 9, 2025 by 4 Comments

Beyblade spinning tops are pretty easy to find at toy shops, department stores, and even some supermarkets. However, the arenas in which the tops do battle? They’re much harder to come by, and the ones on sale in any given market often leave a lot to be desired. [LeftBurst] got around this problem by printing a grandiose Beyblade arena.

[LeftBurst]’s desire was to score a Beyblade stadium more similar to those featured in the anime, which are much larger than those sold as part of the official toy line. [Buddha] was enlisted to model the massive arena, but it then needed to be printed. Given its size, printing it in one piece wasn’t very practical. Instead, [LeftBurst] decided to print it in segments which would then have to be assembled. Super glue was used to put all the parts together, but there was more left to do. The surface finish and joins between the parts would cause issues for tops trying to move across the surface. Thus ensued a great deal of post-processing with primer, putty, and a power sander.

The final result is a massive stadium that plays well, and is ideal for larger multi-Beyblade battles that are more akin to what you’d see in the anime. If you’re playing at this scale, you might appreciate some upgraded launcher technology, too.

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Learn C With A Lisp

August 9, 2025 by 19 Comments

One reason Forth remains popular is that it is very simple to create, but also very powerful. But there’s an even older language that can make the same claim: LISP. Sure, some people think that’s an acronym for “lots of irritating spurious parenthesis,” but if you can get past the strange syntax, the language is elegant and deceptively simple, at least at its core. Now, [Daniel Holden] challenges you to build your own Lisp as a way to learn C programming.

It shouldn’t be surprising that LISP is fairly simple. It was the second-oldest language, showing up in the late 1950s with implementations in the early 1960s. The old hardware couldn’t do much by today’s standards, so it is reasonable that LISP has to be somewhat economical.

With LISP, everything is a list, which means you can freely treat code as data and manipulate it. Lists can contain items like symbols, numbers, and other lists. This is somewhat annoying to C, which likes things to have particular types, so that’s one challenge to writing the code.

While we know a little LISP, we aren’t completely sold that building your own is a good way to learn C. But if you like LISP, it might be good motivation. We might be more inclined to suggest Jones on Forth as a good language project, but, then again, it is good to have choices. Of course, you could choose not to choose and try Forsp.

One File, Six Formats: Just Change The Extension

August 8, 2025 by 39 Comments

Normally, if you change a file’s extension in Windows, it doesn’t do anything positive. It just makes the file open in the wrong programs that can’t decode what’s inside. However, [PortalRunner] has crafted a file that can behave as six different filetypes, simply by swapping out the extension at the end of the filename.

The basic concept is simple enough. [PortalRunner] simply found a bunch of different file formats that could feasibly be crammed in together into a single file without corrupting each other or confusing software that loads these files.

It all comes down to how file formats work. File extensions are mostly meaningless to the content of a file—they’re just a shorthand guide so an operating system can figure out which program should load them. In fact, most files have headers inside that indicate to software what they are and how their content is formatted. For this reason, you can often rename a .PNG file to .JPEG and it will still load—because the operating system will still fire up an image viewer app, and that app will use headers to understand that it’s actually a PNG and not a JPEG at heart, and process it in the proper way.

[PortalRunner] found a way to merge the headers of various formats, creating a file that could be many different types. The single file contains data for a PNG image, an MP4 video, a PDF document, a ZIP archive, a Powerpoint presentation, and an HTML webpage. The data chunks for each format are lumped into one big file, with the combined headers at the very top. The hijinx required to pull this off put some limitations on what the file can contain, and the files won’t work with all software… but it’s still one file that has six formats inside.

This doesn’t work for every format. You can’t really combine GIF or PNG for example, as each format requires a different initial set of characters that have to be at the very beginning of the file. Other formats aren’t so persnickety, though, and you can combine their headers in a way that mostly works if you do it just right.

If you love diving into the binary specifics of how file formats work, this is a great project to dive into. We’ve seen similarly mind-bending antics from [PortalRunner] before, like when they turned Portal 2 into a webserver. Video after the break.

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