3D Printing a Telescope is Rewarding, Even if Not Always Cheaper

What can one expect from 3D printing an 8″ Newtonian telescope? [Molly Wakeling] shares her thoughts after doing exactly that. The performance was on par with any solid 8″ telescope, but in the end it wasn’t really any cheaper than purchasing a manufactured unit. Does that mean it wasn’t worth it? Not at all!

[Molly] makes the excellent observation that the process of printing and building one’s own telescope is highly educational and rewarding. Also, the end result is modular, user-serviceable, and customizable in a way that many commercial offerings can only dream of. It’s a great conversation starter with other enthusiasts, as well!

[Molly] printed the 203 Leavitt design (3d models available on Printables) which is an 8″ Newtonian telescope. This telescope design uses a concave parabolic mirror (a significant part of the expense) at the back of the tube to gather and focus light, and a small flat mirror near the front of the tube reflects this light to an eyepiece on the side. The wood stand makes things convenient, and we like the elastic tie-down used as a simple way to put tension on the mounts.

Do you find yourself intrigued but would prefer to start a little smaller and cheaper? Good news, because the same designer of the 203 Leavitt has a very similar design we happen to have featured before: the 114 Hadley. It features easily obtainable, lower-cost optics which perform well and can be easily ordered online, making it a great DIY starter telescope.

hackaday.com/2025/12/29/3d-pri…

39C3: Recreating Sandstorm

Some synthesizer sounds are just catchy, but some of them are genre-defining. We think you could make that case for the Roland JP-8000 patch “Sandstorm”, which you’ve heard if you listened to any trance from the 90’s, but especially the song that was named after it.

“Sandstorm” is powered by the Roland Supersaw, and synth nerds have argued for a decade about how it’s made. The JP-8000 is a digital synthesizer, though, so it’s just code, run through custom DSP chips. If you could reverse engineer these chips, make a virtual machine, and send them the right program, you could get the sound 100% right. Think MAME but for synthesizers.

That brings us to [giulioz]’s talk at the 39th Chaos Communication Congress, where he dives deep into the custom DSP chip at the heart of the JP-8000. He and his crew had approached older digital synths by decapping and mapping out the logic, as you often do in video game emulation. Here, getting the connections right turned out to be simply too daunting, so he found a simpler device that had a test mode that, combined with knowledge of the chip architecture, helped him to figure out the undocumented DSP chip’s instruction set.

After essentially recreating the datasheet from first principles for a custom chip, [guiloz] and team could finally answer the burning question: “how does the Supersaw work”? The horrifying answer, after all this effort, is that it’s exactly what you’d expect — seven sawtooth waves, slightly detuned, and layered over each other. Just what it sounds like.

The real end result is an emulation that’s every bit (tee-hee!) as good as the original, because it’s been checked out on a logic analyzer. But the real fun is the voyage. Go give the talk a watch.

hackaday.com/2025/12/29/39c3-r…

Different Algorithms Sort Christmas Lights

Sorting algorithms are a common exercise for new programmers, and for good reason: they introduce many programming fundamentals at once, including loops and conditionals, arrays and lists, comparisons, algorithmic complexity, and the tradeoff between correctness and performance. As a fun Christmas project, [Scripsi] set out to implement twelve different sorting algorithms over twelve days, using Christmas lights as the sorting medium.

The lights in use here are strings of WS2812 addressable LED strips, with the program set up to assign random hue values to each of the lights in the string. From there, an RP2040-based platform will step through the array of lights and implement the day’s sorting algorithm of choice. When operating on an element in the array the saturation is turned all the way up, helping to show exactly what it’s doing at any specific time. When the sorting algorithm has finished, the microcontroller randomizes the lights and starts the process all over again.

For each of the twelve days of Christmas [Scripsi] has chosen one of twelve of their favorite sorting algorithms. While there are a few oddballs like Bogosort which is a guess-and-check algorithm that might never sort the lights correctly before the next Christmas (although if you want to try to speed this up you can always try an FPGA), there are also a few favorites and some more esoteric ones as well. It’s a great way to get some visualization of how sorting algorithms work, learn a bit about programming fundamentals, and get in the holiday spirit as well.

hackaday.com/2025/12/29/differ…

Keebin’ with Kristina: the One with the Keyboard-Mouse, Again

The astute among you may remember an earlier version of this Russian beauty, the Lapa, which I featured last year around this time. Creator [lemosbor] claims that the worry was less about visual beauty and more about ergonomics. Way more. Well then, let this serve rather nicely as a textbook definition of that old form-follows-function principle.
The lovely Lapa.
See, [lemosbor] believes that the keyboard must adapt to the hands and not the other way around. The main goals were to minimize hand and finger movement as well as the visual attention required of the keyboard itself. No, there were never going to be any screens or RGB, and there likely never will be.

But I refuse to sidestep the obvious beauty in this keyboard, which from the side resembles a stylish and expensive pair of slightly-heeled shoes that were tailored to the contours of the human hand. And let’s not forget those handmade, oval keycaps, which again are a product of form-follows-function.

Underneath those keycaps are extremely light, tactile switches — Kailh White V2s with 30g springs. Now check this out. Those DIY keycaps weren’t just for added fun, they are very lightweight on purpose. They allow [lemosbor] to type more easily and accurately than on square caps. But they created gaps which showed the switches, and the whole effect was evidently quite ugly. To solve this, [lemosbor] designed the case so that the switches are mounted on the bottom. They nestle completely into switch-shaped crevices, so they are held in place only by friction.
See? Kitten heels.
You might be wondering why the wrist wrests are totally different. I suppose I’ve buried the lede, which is that the right half of Lapa operates as a mouse. Like, you move it around the desk.

As you might imagine, this aspect wasn’t easy to design or execute such that the keyboard doesn’t move around like crazy while you’re trying to type. Basically, the right half is quite light by comparison. The cutouts of the honeycombed wrist wrest save on weight while also improving hand contact.

The thumbstick on the right side is used instead of the cursor keys, which [lemosbor] reports as being very convenient. The left side has a thumb toggle switch for choosing between Russian and English. There’s also a left thumbstick, which [lemosbor] uses to switch between tabs and programs.

But the coolest part might be the solenoid hidden under the left wrist rest. It knocks when switching layers, and does so a certain number of times corresponding to the layer so that [lemosbor] is never lost. Since [lemosbor] doesn’t type much English, the solenoid will constantly tap a little bit in English mode. Now I think that would be really fun to type along to, at least for a little while. Imagine what it could do for your flow state.

Via reddit

Claude Plods Along, Emanating From An Enabled Typewriter

As far as AIs go, I’ve personally only used ChatGPT, and I feel somewhat attached to its response style at this point. Honestly, Claude might be a shock to the system. But what wouldn’t be a shock at all is using a typewriter to interact with either one of them.

Hackaday’s own [Ben James] started with a electronic Brother AX-10, and that’s the important distinction here. This type of machine reads your keystrokes just like a computer keyboard, but it tells the daisy wheel print element how to spin, and the paper whether to go up or down.

Thanks to this operation, [Ben] was able to both intercept key presses and inject them. So you see where this is going. You and Claude take turns typing. If only the keys would phantom-depress, like a player piano.

For both processes, [Ben] used an Arduino Nano, which interfaces with the keyboard matrix through four multiplexers — columns, rows, input, and output. The Arduino is wired to a Raspberry Pi Zero W running a Python script that sends prompts to Claude’s API and gets answers in return. See Claude go in the video below.

youtube.com/embed/x4lFOUZCSg4?…

The Centerfold: E-Waste Vintage Battlestation

Believe it or not, these were mostly all pulled out of the e-waste pile just in time, kind of like Indy and the hat. In fact, rescuing stuff from electronics recycling is [ThisLifeSuckss]’ main hobby. Sounds like fun, if you have the space for all that you find. I myself do not.

Do you rock a sweet set of peripherals on a screamin’ desk pad? Send me a picture along with your handle and all the gory details, and you could be featured here!

Historical Clackers: the (Danish) Junior

As the commonplace name suggests, the Junior is meant as a toy for children. But by the looks of it, this would be a fine machine to add to your late 1940s office lineup.

For one thing, it’s almost all metal except for the wooden platen, two ink rollers made of cotton, and a couple of plastic platen knobs. The Antikey Chop declared it incredibly well-built for a toy, though the design is quite simple, clocking in at just 31 total parts.

Because the Junior was assembled largely by pinning or pressing pieces together, it was completely un-serviceable as disassembly would likely cause irreparable damage.

What you could do was change out the typewheel, which was cast, index and type, from one metal piece. It’s unlikely that non-Danish versions were created, however.

In order to use the thing, you would just spin the wheel until the character you want is in the top dead center position, and push the Space bar. This action caused the entire carriage to pivot an inch forward, and would advance the spring-driven escapement by one increment when it came back to rest.

The Return function involves pivoting the carriage forward and pushing to the right. Aside from this functionality, there’s not much to this typewriter. There’s no bell, no lever for Return, and certainly no line space lever or tab stops. After all, it’s a toy. But it would make one hell of a label maker.

Finally, a Scented Mouse for Heated Gaming Sessions

For some reason, the keyboard is called Marshmallow and not the fluffy white mouse, which is known on the streets as Fragrance Mouse. But I think marshmallow is exactly the scent I would want emanating from beneath my hand. Or maybe a nice, calming lavender, which it actually comes with.

The appeal of the keyboard is supposed to be in the muted, natural colors. Okay. That’s fair. Although it comes in three other colorways, I think this ‘green tea latte’ version takes the petit four.

And no matter which colorway you choose, the typography of the alphanumeric key legends is stunning and highly-readable. The white-on-gray of the modifiers and such is highly lacking in the legibility department, however.

As you might imagine, there’s a little tank inside Fragrance Mouse’s belly where you put the essential oils. But don’t worry about spilling, because there’s a porous insert that absorbs them.

Although they are sold separately, both peripherals are supposed to be office-quiet, with scissor keys on the Marshmallow and quiet switches in the mouse. Fragrance Mouse is weird, but I would go for it if it were a nice, comfortable trackball instead. But this thing isn’t even meant for left-handers. It should be hitting Microcenter soon, but you’ll have to buy the Marshmallow keyboard from ASUS directly.

Got a hot tip that has like, anything to do with keyboards? Help me out by sending in a link or two. Don’t want all the Hackaday scribes to see it? Feel free to email me directly.

hackaday.com/2025/12/29/keebin…

39C3: Hacking Washing Machines

Many of us have them, few of us really hack on them: well, here we’re talking about large home appliances. [Severin von Wnuck-Lipinski] and [Hajo Noerenberg] were both working on washing machines, found each other, and formed a glorious cooperation that ended in the unholy union of German super-brands Miele and B/S/H — a Miele washer remote controlled by Siemens’ web app.

This talk, given at the 39th Chaos Communication Congress (39C3), is about much more than the stunt hack, however. In fact, we covered [Severin]’s work on the very clever, but proprietary, Miele Diagnostic Interface a little while ago. But now, he’s got it fully integrated into his home automation system. It’s a great hack, and you can implement it without even opening the box.

About halfway through the talk, [Hajo] takes over, dissecting the internal D-Bus communication protocol. Here, you have to open up the box, but then you get easy access to everything about the internal state of the machine. And D-Bus seems to be used in a wide range of B/S/H/ home appliances, so this overview should give you footing for your own experimentation on coffee machines or dishwashers as well. Of course, he wires up an ESP32 to the bus, and connects everything, at the lowest level, to his home automation system, but he also went the extra mile and wrote up a software stack to support it.

It’s a great talk, with equal parts humor and heroic hacking. If you’re thinking about expanding out your own home automation setup, or are even just curious about what goes on inside those machines these days, you should absolutely give it a watch.

Editor Note: The “S” is Siemens, which is Hackaday’s parent company’s parent company. Needless to say, they had nothing to do with this work or our reporting on it.

hackaday.com/2025/12/29/39c3-h…