Tearing down hardware from different parts of the world can be revealing, showing unique parts, techniques, and tricks employed by engineers living in a very different world from our own. To that end, [msylvain59] has been kind enough to give us a look inside the Elektronika MK-26—a calculator built in the former Soviet Union.

There’s lots of interesting stuff to see from the get-go. The oddball button pad is covered in Cyrillic symbols, quite alien to those of us more accustomed to the Latin character set. It’s also constructed somewhat unlike more familiar models from Western-aligned companies like Casio or Commodore. It also rattles when shaken, which doesn’t inspire confidence. Inside, it’s got old-school brown PCBs without the usual green solder mask, a chunky IC in a weird package, and display is via a power-hungry VFD.

It doesn’t look so totally alien inside; much of the construction is pretty typical of the mid-1970s, wherever you went around the world. The most striking differences are more in the graphics and visual design than anything else.

Ultimately, there are reasons why manufacturers around the world tend to converge on similar techniques. Generally, it’s because it’s more economical or easier to do things a certain way. And yet, we still see regional variances because conditions, technologies, and parts availability varies around the world. This teardown highlights that quite clearly.

If you’re just getting a taste for Soviet hardware teardowns, you’ll love this video diving inside a real Soyuz clock.

These days, when you think reverb, you probably think about a guitar pedal or a plugin in your audio software. But you can also create reverb with a big metal plate and the right supporting electronics. [Tully] from [The Tul Studio] shows us how.

Basically, if you’ve ever smacked a big sheet of metal and heard the thunderous, rippling sound it makes, you already understand the concept here. To turn it into a studio effect, you use transducers to deliver the sound into the plate of metal, and then microphones to pick it back up again at some other point on the plate. Since the sound takes time to travel through the plate, you get a reverb effect.

[The Tul Studio] used a huge cold-rolled steel plate, standing one meter wide and two meters tall. The plate itself is hung from picture chain, which is strong enough to carry its weight. Old car tweeters are repurposed to act as pickups, while a larger speaker is used to drive sound into the plate. “The key to making it sound not like a tin can is the actual EQ and the electronics,” [Tully] explains, providing resources for this purposes.

We love lots of lovely reverbing things around these parts; oddball delays, too! Video after the break.

 

Distortion pedals and overdrive effects usually have a bunch of lovely transistors or op-amps inside and lots of knobs and dials to tweak the sound to your personal taste. However, it’s possible to get some crunchiness in your audio signal without all that fuss, as [Simon Hutchinson] demonstrates with his $2 “analog saturation box”.

The effect is achieved quite simply by installing a pair of diodes in opposite orientations, connected from the signal path to ground. This configuration is also known as wiring diodes in “anti-parallel.” When the signal increases in amplitude beyond the diode’s forward voltage, the diode conducts and the signal’s peak is clipped off, which creates a distorted tone. Since there are two diodes, one in each orientation, both the tops and bottoms of the AC audio signal are clipped in this manner.

The amount of clipping is highly dependent on the diodes chosen and the strength of the signal you’re working with. Silicon diodes clip around 0.7 V, while germanium diodes clip at about 0.3 V, but that doesn’t give you much flexibility. You can work with this to some degree, though. You can up the minimum clipping level by stacking more diodes in series in each direction, or you can put in a potentiometer to vary your signal’s level before it hits the diodes. Really, though, this hard voltage limit is why more commonly, we use active distortion or overdrive effects that have more options for gain and level and such.

[Simon Hutchinson] does an able job of explaining the effect and demonstrates its use with some simple beats. As a passive device, it’s pretty one note—there’s no EQs to mess with the frequency response, and no ability to change anything else about the sound, either. Still, it’s interesting to hear the effect it does have on a signal, and you might just find this is all the distortion you need. If you’d rather go into full-fat distortion though, we’ve covered that too.

Got some spare filament and looking to build a guitar you can truly call your own? [The 3D Print Zone] has created a modular 3D printable guitar system that lets you easily mix and match different components for the ultimate in customization.

The build is based around a central core, which combines the pickups, bridge, and neck into one solid unit. This is really the heart of the guitar, containing all the pieces that need to be in precise alignment to get those strings vibrating precisely in tune. The core then mounts to a printed outer body via mating slots and rails, which in the main demo is made to look like a Les Paul-style design. This outer body also hosts the volume, tone, and pickup controls. Output from the pickups travels to the controls in the outer body via a set of metallic contacts.

What’s cool about this build is that the sky really is the limit for your creativity. As the video below demonstrates, the main build looks like a Les Paul. But, armed with the right CAD software, you can really make a guitar that looks like whatever you want, while the 3D printer does all the hard work of making it a reality. The files to print the guitar, along with the pickups and other components, are available as kits—but there’s also nothing stopping you from working up your own printed guitar design from scratch, either.

We’ve seen some other great 3D printed guitars before, too.

Stripping and cutting wires can be a tedious and repetitive part of your project. To save time in this regard, [Red] built an automatic stripper and cutter to do the tiring work for him.

An ESP32 runs the show in this build. Via a set of A4988 stepper motor drivers, it controls two NEMA 17 stepper motors which control the motion of the cutting and stripping blades via threaded rods. A third stepper controls a 3D printer extruder to move wires through the device. There’s a rotary encoder with a button for controlling the device, with cutting and stripping settings shown on a small OLED display. It graphically represents the wire for stripping, so you can select the length of the wire and how much insulation you want stripped off each end. You merely need select the measurements on the display, press a button, and the machine strips and cuts the wire for you. The wires end up in a tidy little 3D-printed bin for collection.

The build should be a big time saver for [Red], who will no longer have to manually cut and strip wires for future builds. We’ve featured some other neat wire stripper builds before, too. Video after the break.

There are plenty of audio mixers on the market, and the vast majority all look the same. If you wanted something different, or just a nice learning experience, you could craft your own instead. That’s precisely what [Something Physical] did. 

The build was inspired by an earlier 3-channel mixer designed by [Moritz Klein]. This project stretches to eight channels, which is nice, because somehow it feels right that a mixer’s total channels always land on a multiple of four. As you might expect, the internals are fairly straightforward—it’s just about lacing together all the separate op-amp gain stages, pots, and jacks, as well as a power LED so you can tell when it’s switched on. It’s all wrapped up in a slant-faced wooden box with an aluminum face plate and Dymo labels. Old-school, functional, and fit for purpose.

It’s a simple build, but a satisfying one; there’s something beautiful about recording on audio gear you’ve hewn yourself. Once you’ve built your mixer, you might like to experiment in the weird world of no-input mixing. Video after the break.

For most of us, mirrors are something we buy instead of build. However, [Unnecessary Automation] wanted to craft mirrors of his own for a custom telescope build. As it turns out, producing optically-useful mirrors is not exactly easy.

For the telescope build in question, [Unnecessary Automation] needed a concave mirror. Trying to get that sort of shape with glass can be difficult. However, there’s such a thing as a “liquid mirror” where spinning fluid forms into a parabolic-like shape. Thus came the idea to spin liquid resin during curing to try and create a mirror with the right shape.

That didn’t quite work, but it inspired a more advanced setup where a spinning bowl and dense glycerine fluid was used to craft a silicone mold with a convex shape. This could then be used to produce a resin-based mirror in a relatively stationary fashion. From there, it was just necessary to plate a shiny metal layer on to the final part to create the mirror effect. Unfortunately, the end result was too messy to use as a viable telescope mirror, but we learn a lot about what didn’t work along the way.

The video is a great journey of trial and error. Sometimes, figuring out how to do something is the fun part of a project, even if you don’t always succeed. If you’ve got ideas on how to successfully spin cast a quality mirror, drop them in the comments below. We’ve seen others explore mirror making techniques before, too.

You can buy all sorts of RC cars off the shelf, but doing so won’t teach you a whole lot. Alternatively, you could follow [TRDB]’s example, and design your own from scratch.

The Lizard, as it is known, is a fun little RC car. It’s got a vaguely Formula 1-inspired aesthetic, and looks fetching with the aid of two-tone 3D printed parts. It’s designed for speed and handling, with a rear-wheel-drive layout and sprung suspension at all four corners to soak up the bumps. The majority of the vehicle is 3D printed in PETG, including the body and the gearbox and differential. However, some suspension components are made in TPU for greater flexibility and resistance to impact. [TRDB] specified commercial off-the-shelf wheels to provide good grip that couldn’t easily be achieved with 3D-printed tires. An ESP32 is responsible for receiving commands from [TRDB’s] custom RC controller running the same microcontroller. It sends commands to the speed controller that runs the Lizard’s brushed DC motor from a 3S lithium-polymer battery.

The final product looks sleek and handles well. It also achieved a GPS-verified top speed of 48 km/h as per [TRDB’s] testing. We’ve seen some other great DIY RC cars over the years, too, like this example that focuses on performance fundamentals. Video after the break.

The Radio Shack TRS-80 was a much-loved machine across America. However, one thing it lacked was MIDI. That’s not so strange given the era it was released in, of course. Nevertheless, [Michael Wessel] has seen fit to correct this by creating the MIDI/80—a soundcard and MIDI interface for this old-school beast.

The core of the build is a BluePill STM32F103C8T6 microcontroller, running at a mighty 75 MHz. Plugged into the TRS-80s expansion port, the microcontroller is responsible for talking to the computer and translating incoming and outgoing MIDI signals as needed. Naturally, you can equip it with full-size classic DIN sockets for MIDI IN and MIDI OUT using an Adafruit breakout module. None of that MIDI Thru nonsense, though, that just makes people uncomfortable. The card is fully capable of reproducing General MIDI sounds, too, either via plugging in a Waveblaster sound module to the relevant header, or by hooking up a Roland Sound Canvas or similar to the MIDI/80s MIDI Out socket. Software-wise, there’s already a whole MIDI ecosystem developing around this new hardware. There’s a TRS-80 drum tracker and a synthesizer program, all with demo songs included. Compatibility wise, The MIDI/80 works with the TRS-80 Model I, III, and 4.

Does this mean the TRS-80 will become a new darling of the tracker and chiptune communities? We can only hope so! Meanwhile, if you want more background on this famous machine, we’ve looked into that, too. Video after the break.

[3DSage] likes building replicas of hardware from movies and video games, often with a functional twist. His latest build aimed to bring the Codec from Metal Gear Solid to life.

If you haven’t played the Metal Gear games, the Codec has been modelled somewhat like an advanced walkie talkie at times, but has often been kept off-screen. Thus, [3DSage] had a great deal of creative latitude to create a realistic-feeling Codec device that provided voice communications and some simple imagery display.

The resulting build relies on an RP2040 microcontroller to run the show. It’s paired with an MPU6050 3-axis gyroscope and accelerometer for motion control of the device’s functionality, and features a small LCD screen to mimic the display in the games. A kids walkie-talkie kit was leveraged for audio communication, but kitted out with a better microphone than standard. Power is via a rechargeable 9V battery, which is really a lithium-ion and USB charging board packed into the familiar 9V form factor.

Where the build really shines, though, is the aesthetic. [3DSage] managed to capture the military-like look and feel as well as authentically recreate the graphics from the games on the screen. The simulated noise on the display is particularly charming. Beyond that, the 3D-printed enclosures leverage texture and multi-color printing really well to nail the fit and finish.

Ultimately, the Codec isn’t much more than a glorified walkie talkie. Even still, [3DSage] was able to create an impressive prop that actually does most of what the device can do in game. If you’ve ever coveted a PipBoy or tricorder, this is one project you’ll be able to appreciate.

Portal 2 is mostly known as the successful sequel to Valve’s weird physics platformer, Portal. It’s not really known for being a webserver. That might change, though, given the hard work of [PortalRunner].

Quite literally, [PortalRunner] hacked the Source engine and Portal 2 to actually run a working HTTP web server. That required setting up the code to implement a TCP network socket that was suitable for web traffic, since the engine primarily functions with UDP sockets for multiplayer use. This was achieved with a feature initially put in the Source engine for server management in the Left 4 Dead games. From there, the game engine just had to be set up to reply to HTTP requests on that socket with the proper responses a visiting browser expects. If the game engine responds to a browser’s connection request with a bunch of HTML, that’s what the browser will display. Bam! You’ve got a web server running in Portal 2.

From there, [PortalRunner] went further, setting things up so that the status of in-game objects effects the HTML served up to visiting web browsers. Move objects in the game, and the served web page changes. It’s pretty fun, and the complexity and features [PortalRunner] implements only get more advanced from there. When he gets into stacking companion cubes to write HTML in visual form, you’ll want to applaud the Minecraftian glory of it all.

The devil is really in the details on this one, and it’s a great watch. In reality, making Portal 2 into a simple web server is far easier than you might have thought possible. Valve’s physics masterpiece really is popular with hackers; we see it popping up around here all the time. Video after the break.

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.

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.

[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!

Last week, we examined a Doom port for the venerable Atari ST. As is so often the way with this thing, one netted another, and [Steve] wrote in to inform us about a different version under the name DOOM8088ST.

The port is so named because it’s based on Doom8088, which was originally written for DOS machines running Intel 8088 or 286 CPUs. Both ports are the work of [FrenkelS], and aims to bring the Doom experience into the far more resource constrained environment of the Atari ST. There is only very limited sound, no saving, and it only supports Doom 1 Episode 1. Still, it’s quite recognizable as Doom!

Doom8088ST is tunable to various levels of performance, depending on what you’re running it on. Low mode (30 x 128) is suitable for stock Atari ST machines running at 8 MHz. It’s described as having “excellent” framerate and is very playable. If you’ve got an upgraded ST or Mega STe, you can try Medium (60 x 128), which has greatly improved visuals but is a lot heavier to run.

Files are on Github for those interested to run or tinker with the code. Don’t forget to check out the other port we featured last week, either, in the form of STDOOM. Video after the break.

[Thanks to Steve for the tip!]

The Commodore 64 may remain the best selling computer of all time, but it has one major flaw. It doesn’t have HDMI! That makes it a total pain to use with modern displays. Thankfully, [Side Projects Lab] has whipped up an HDMI output board to solve this concerning oversight from the original designers.

The project was inspired by work by [Copper Dragon], who whipped up a nifty RGB output board. This device worked by reading the inputs to the C64’s VIC II graphics chip, which it then used to recreate a pixel-perfect video frames to then produce a quality analog video output. [Side Projects Lab] figured the same interception technique would be useful for producing a quality HDMI output.

The result was the HD-64. It sits inside the C64 in place of the original RF modulator. It uses an interleaver socket to capture digital signals going to the VIC II. It then feeds these signals to an emulated VIC II running inside an FPGA, which creates the pixel-perfect screen representation and synthesizes the proper digital HDMI output. Meanwhile, the analog audio output from the SID chip is captured from the RF modulator’s original header, and sent out via the HDMI output as well. The default output is super-sharp, but the device can be configured to allow scanlines and anti-aliasing if that’s more to your tastes.

If you want to hook your C64 up to a modern screen, this is going to be one of the tidiest and sharpest ways to do it. We’ve seen similar hacks for other platforms before, too. Video after the break.

[Thanks to RobIII for the tip!]

The M.2 slot is usually used for solid-state storage devices. However, [bitluni] had another fun idea for how to use the interface. He built an M.2 compatible LED matrix that adds a little light to your motherboard.

[bitluni] noted that the M.2 interface is remarkably flexible, able to offer everything from SATA connections to USB, PCI Express, and more. For this project, he elected to rely on PCI Express communication, using a WCH CH382 chip to translate from that interface to regular old serial communication.

He then hooked up the serial interface to a CH32V208 microcontroller, which was tasked with driving a 12×20 monochrome LED matrix. Even better, he was even able to set the microcontroller up to make it programmable upon first plugging it into a machine, thanks to its bootloader supporting serial programming out of the box. Some teething issues required rework and modification, but soon enough, [bitluni] had the LEDs blinking with the best of them. He then built a web-based drawing tool that could send artwork over serial direct to the matrix.

While most of us are using our M.2 slots for more traditional devices, it’s neat to see this build leverage them for another use. We could imagine displays like this becoming a neat little add-on to a blingy computer build for those with a slot or two to spare. Meanwhile, if you want to learn more about M.2, we’ve dived into the topic before.

Typically, when we think about forming metal parts, we think about beating them with hammers, or squeezing them with big hydraulic presses. But what if magnets could do the squeezing? As it turns out—Grumman Aerospace discovered they can, several decades ago! Even better, they summed up this technique in a great educational video which we’ve placed below the break.

The video concerns the development of the Grumman EMF Torque Tube. The parts are essentially tubes with gear-like fittings mounted in either end, which are fixed with electromagnetic forming techniques instead of riveting or crimping. Right away, we’re told the key benefits—torque tubes built this way are “stronger, lighter, and more fatigue resistant” than those built with conventional techniques. Grumman used these torque tubes in such famous aircraft as the F-14 Tomcat, highlighting their performance and reliability.

The video goes on to explain the basics of the EMF torque tube production process. A tube is placed inside a coil, with the end fitting then installed inside. A capacitor bank dumps current through the coil to generate a strong electromagnetic field. This field is opposed by a secondary field generated by eddy currents. The two forces result in an explosive force which drives the tube inwards, gripping into the grooves of the end fitting, and destroys the coil in the process. Grumman notes that it specifically optimized a grooving profile for bonding tubes with end fittings, which maximised the strength of these EMF-produced joints.

This tip was sent in by [irox]. The video itself was posted by [Greg Benoit], who notes his father Robert Benoit was intimately involved with the development of the technique. Indeed, it was useful enough that the technology was licensed to Boeing, generating many millions of dollars for Grumman.

We feature all kinds of machining and forming techniques here, but this sort of forming isn’t something we see a lot of around these parts. Still, we’re sure someone will be Kickstarting a home EMF forming machine before the end of next week.

[Dmytro] was able to lay his hands on a InfiRay T2S+ camera. It’s a capable thermal imaging unit that comes at a cheaper price than many of its rivals. [Dmytro] decided to pull it apart to see what makes it tick, and he discovered a few interesting things along the way.

Like so much modern hardware, pulling the case apart does require some spudging and levering. Once inside, though, it comes apart in a relatively straightforward manner. Once inside, [Dmytro] notes some similarities between this camera and the Flir Lepton, another affordable thermal camera on the market. He also finds a clone of the Cypress FX2LP chip, which is used for talking USB. There’s also an Gowin FPGA inside, with [Dmytro] suspecting the gateware onboard could be modified. If so, the camera may be a candidate for running open source firmware in future.

What bothered [Dmytro] about this camera, though, was the software. When used with an Android phone, the camera demands the use of a proprietary app with with questionable permissions. It can be used on a regular computer, where it appears as a standard webcam. However, in this mode, the camera fails to self-calibrate, and the images quickly become useless. [Dmytro] worked to hack around this, by figuring out a way to trigger calibrations and run the proper image corrections manually when using the camera without the smartphone app. He also explores techniques to improve the resolution of the thermal measurements made by the camera.

We’ve seen some other neat thermal camera hacks over the years. Video after the break.

[Thanks to Clint for the tip!]

Typing can be difficult to learn at the best of times. Until you get the muscle memory down, it can be quite challenging. However, if you’ve had one or more fingers amputated, it can be even more difficult. Just reaching the keys properly can be a challenge. To help in this regard, [Roei Weiman] built some assistive typing tools for those looking for a little aid at the keyboard.

The devices were built for [Yoni], who works in tech and has two amputated fingers. [Roei] worked on many revisions to create a viable brace and extension device that would help [Yoni] type with greater accuracy and speed.

While [Roei] designed the parts for SLS 3D printing, it’s not mandatory—these can easily be produced on an FDM printer, too. For SLS users, nylon is recommended, while FDM printers will probably find best results with PETG. It may also be desirable to perform a silicone casting to add a grippier surface to some of the parts, a process we’ve explored previously.

The great thing about 3D printing is that it enables just about anyone to have a go at producing their own simple assistive aids like these. Files are on Instructables for the curious. Video after the break.