Author: Bryan Cockfield

1797 Articles

PenPal, A Robotic Drawing Assistant

April 25, 2026 by 1 Comment

Emergent properties include examples like murmurations of starlings which can’t be predicted from looking at a single bird, weather which can’t be predicted by looking at a few air molecules, and consciousness which can’t be predicted by looking at a neuron. Likewise, when adding a new tool to a workflow, emergent properties can show up as well. A group at Chicago University developed a robotic drawing tool and a few artists developed some unique drawing methods using it.

The robotic pen uses a pair of tendons to extend the working end out a certain amount. From there it uses a set of servos to can be programmed to revolve around in a defined path, making repeating movements while the artist makes larger movements over the paper. Originally meant for shading, small circles or simpler back-and-forth movements were preset, but with full control over the pen’s behavior the artist can shift focus away to other tasks within the creative process. A study with ten participants was done which showed artists coming up with novel ways of using a tool like this, and others reporting that it’s almost like drawing together with another person.

Looking for novel ways that humans can interact with computers and robots can often lead to surprising outcomes like this. Members of this group aren’t new to novel human interface devices either; they’ve also built a squishy dynamic button as well.

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Audio-Forward Case Mod Of Classic 90s Portable TV

April 24, 2026 by 6 Comments

The humble cathode ray tube (CRT) was once the technology behind almost all of our televisions and computer displays. Its replacements, from LCD screens to OLED and others, are generally cheaper to make and better to look at. Old televisions were comparatively large as well, but their size can be an advantage for people like [ManicMods] aka [Jeff]. His latest build ditches the CRT from an old Bently portable TV and uses the huge space available in the case for a hi-fi audio system and some other parts that turn it into an impressive portable home theater system.

After removing most of the internals of the TV, the first part to go in is the stereo and subwoofer combo as it takes up the most amount of space. The subwoofer section points downward and the two stereo speakers are mounted to the sides. To free up the most space inside, the new display is mounted forward of the original bezel, with a new 3D printed one helping to hold it in place. Behind it goes a Raspberry Pi, loaded with the moOde audio player, a high quality DAC for audio output, and a 1 TB SSD with [Jeff]’s uncompressed audio library. Most of the ports are extended out to the case including the SD card slot so other operating systems can be loaded on the Pi, and there are a ton of options for hooking up external speakers and displays as well, making it an extremely modular and expandable portable media center.

Also added to the finished product are a few small game controllers, since the Pi is perfectly capable of playing retro games, as well as a small wireless keyboard and trackpad combo. Although the CRT’s demise will be felt harder by some than by others, the original look of the case is preserved somewhat by keeping the original tuning display and locations of the original control buttons and knobs. If preserving the CRTs are of upmost importance, though, this build used a pair of them in a VR headset.

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Photographing Rocket Chute Deployment At 10 Km

April 22, 2026 by 18 Comments

For those who haven’t been following along, [BPS.space] aka [Joe] is on a journey to launch a home-built rocket past the Kármán line where it will officially reach outer space. But one does not simply launch a rocket to outer space on the first try. The process is long and involves not only building a series of rockets, but designing and building propellant mixtures, solving aerodynamic problems, gaining several model rocket certifications along the way, and a whole host of other steps. He’s also documenting the entire process on video as well, which involves some custom camera work like this rocket selfie camera which will take an image of his rockets at apogee.

Like most problems in high-power rocketry, extremely tiny problems have a way of causing catastrophic failure, so every detail needs to be considered and planned for in the final design. For a camera that needs to jettison itself from the rocket at a precise moment after experiencing an incredible amount of forces, this is a complicated problem to solve. The initial design involves building a sled for a small deconstructed GoPro which uses springs and a servo to launch itself out of the rocket. The major problem with the design is that even the smallest torque on the sled will cause the camera to point in a random direction by the time it’s far enough from the rocket to take a picture. [Joe] tried a number of design iterations but could not get these torques to vanish.

One of the design limitations with this camera is that it won’t have any sort of parachute or tether itself to the rocket, so it will hit the ground at its terminal velocity. To keep that velocity down and improve survivability chances of the footage, the mass has to stay low. Eventually he settled on a semi-active control system by mounting a brass weight on a small motor, giving the camera module enough stability to stay pointed at the rocket long enough to take the video. Even though it hasn’t flown yet, admitting his first design wasn’t working at compromising on this solution which adds a bit of mass seems to be a good design change. We’ve been following along with his entire process so be sure to check out his actual rocket motor builds and teardowns as well.

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DIY Smart Button Gets Surprisingly Complicated

April 22, 2026 by 3 Comments

There’s a reason that the standards specifications for various wireless communications protocols are extremely long and detailed. [Made by Dennis] found this out first hand when he decided to build a wireless button from scratch.

The major issues with wireless devices is one of power consumption. If reliable power is available from a wall plug or solar panel, this isn’t as serious of a concern. But [Dennis] is using batteries for his buttons, so minimizing power consumption is a priority. He’s going with the nRF52, a microcontroller designed for low power and which has a built in wireless radio, and configuring it in a way that uses the least amount of energy possible.

From there, [Dennis] turns to the wireless communication. He goes into detail about how the microcontroller is woken up, how it sends its data packets to another wireless-enabled microcontroller, and how they handle handshakes and acknowledgements of data. For something as simple as a button press, it gets quickly more complicated especially when adding some basic encryption and security to the communications protocol.

With all the design decisions out of the way, the system can be built. [Dennis] has created custom PCBs for his devices, and also included some expansion I/O for other sensors and peripherals beyond just a pushbutton. All of the schematics and code are available on the project’s GitHub page and the STL files can be found at Printables.

For those new to offline home automation or who are turning away from cloud-based services lately, there are some easy entry points that don’t require much extra hardware or expenditure.

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Quirky Electric Car Rides The Rails

April 19, 2026 by 22 Comments

We wouldn’t be surprised if you’d never seen the Spira before. The lightweight three-wheel vehicle is closer to a go-kart than a traditional car, and that’s before you even get to the foam body panels. But even the most niche of products enjoys a certain fandom, and [Matt Spears] certainly seems to love working on his Spira. His latest video documents the new modifications he’s made to the car in an effort to ride it on abandoned railroad tracks in the western United States.

His first attempt at riding the rails worked pretty well but he hit an obstruction at high speed which destroyed his front axle and damaged a few other parts on the vehicle, which gave him a perfect excuse to make some upgrades. He swapped the old rear axle out with one from a go-kart, complete with custom wheels and a new braking system. The drivetrain received an upgrade with a 5 kW electric motor, and although [Matt] planned on casting new wheels for the higher speeds, the chemicals he needed didn’t arrive in time. So, to test the new vehicle he repurposed some old wheels just to get the Spria back out on the tracks.

The test run went so well that [Matt] ended up pushing the vehicle farther than he had ever been on this abandoned rail, including over a questionable trestle and far out into the wilderness. Hopefully we’ll see more videos of [Matt] taking this car to explore even more remote places. In the meantime, take a look at some simpler, non-electric vehicles that are often used to explore abandoned rail lines in California.

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Game Cube Hot Tub Animation Brought Into Real World

April 17, 2026 by 1 Comment

Unlike the current era where most consumer electronics are black rectangles, or the early 90s where most consumer electronics were black rectangles, we got a brief glimmer of color, light, and hope in the 2000s. Cell phones had all kinds of shapes and sizes, laptops came in bright colors, and even video game consoles got in on the fun. The Nintendo GameCube not only featured its namesake shape but came in several vibrant colors, most famously a bright purple. In fact, its design was such a hit that it continues to inspire artists and console modders alike. An animator named [kidd.gorgeous] recently envisioned a GameCube as a hot tub, and [BigRig Creates] set out to make this animation a reality.

Of course, this won’t be a life-sized hot tub capable of holding a human, but [BigRig Creates] did want it to be a usable, playable Game Cube with all of the features from the animation present in the final version. Since the lid won’t be operational with a hot tub model on the top lest all of the water spill out every time a game is changed, he’s modified it with some modern tools to hold his games inside the console itself. With the case open he’s also added the LED accent lighting featured in the animation as well as added the 3D-printed hot tub to the top. The hot tub is filled with mineral oil for electronics safety, and has a small pump built in to give the appearance of a working hot tub.

The buttons around the outside are functional as well, toggling the various lighting features and hot tub operation. And of course, the console diorama is fully playable, with the staircase railing able to easily detach in order to access the leftmost controller ports. It’s a faithful adaptation of the original animation, and [BigRig Creates] has a few games on queue that are properly themed for the new hot tub addition like Wave Race 64, Super Mario Sunshine, and Pool Paradise.

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New Display For Old Multimeter

April 14, 2026 by 14 Comments

As a company, Fluke has been making electronic test equipment longer than the bipolar junction transistor has been around for. In that time they’ve developed a fairly stellar reputation for quality and consistency, but like any company they don’t support their products indefinitely. [ogdento] owns a Fluke meter that isn’t nearly as old as the BJT but still has an age well outside of the support window, and since the main problem was the broken LCD display they set about building a replacement for this retro multimeter.

Initially, [ogdento] had plans to retrofit this classic multimeter with a modern OLED, but could not find enough space for the display or a way to drive it easily. The next attempt to get something working was to build a custom one-off LCD using a drill press as an end mill, which didn’t work either. But after seeing a Charlieplexed display from [bobricius] as well as this video from EEVblog about designing custom LCDs, [ogdento] was able to not only design a custom PCB and LCD display to match the original meter, but was able to get a manufacturer in China to build them.

The new displays have a few improvements over the old; mostly they are more stylistically inspired by later Fluke models and have a few modern improvements to the LCD itself. There were are few issues during prototyping but nothing that was too hard to sort out, such as ordering the wrong size elastomeric strips initially. For anyone who needs to replace a custom LCD and can’t find replacement parts anymore, this project would be a great starting point for figuring out the process from the ground up.