The Clever Design Behind Everyday Traffic Poles

Ever stopped at a red light and noticed something odd about the poles holding up the traffic lights? Look closer next time—many of them appear to hover just above the concrete, anchored by visible bolts. This video below explains it all. It’s not a job left unfinished. It is actually clever design, and all about functionality and easy maintenance. Let’s break down why engineers prefer this so-called ‘floating’ base plate setup.

At first, you might think mounting poles directly into concrete would be more stable—after all, that’s how heavy columns are often installed. But traffic light poles are lightweight, hollow, and face constant wind pressure. Instead of brute stability, they need flexibility and precise alignment. Enter the standoff base plate. By resting on leveling nuts, these poles can be fine-tuned for perfect verticality, even when the ground shifts slightly over time. That’s critical for keeping your 30-foot pole from leaning like the Tower of Pisa.

The open design also simplifies maintenance. If the pole tilts after years of wear, it takes just a few nut adjustments to fix it—no heavy cranes required. Plus, the gap helps prevent moisture buildup, reducing corrosion. So next time you’re waiting at an intersection, you’ll know it’s not just clever engineering—it’s practical street smarts. If you’re an infrastructure nut, this slightly older article might spark your interest.

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A guy's leg encased in a 3D printer showing a fresh printed tattoo

Do, Dare Or Don’t? Getting Inked By A 3D Printer

This unusual tattoo hack by [Emily The Engineer] is not for the weak of heart, but let’s be frank: we kind of know her for that. And she gives out a warning, albeit at a good 10 minutes in, to not do this at home. What she’s about to do takes creativity and tech obsession to the next level: to transform a 3D printer into a functional tattoo machine. Therefore, [Emily] ingeniously modified one of her standard 3D printers to operate two-dimensionally, swapped its plastic extruder for a tattoo gun, and, yes, even managed to persuade a willing participant to try it out.

The entire process can be seen in [Emily]’s video below, which humorously yet meticulously documents the journey from Sharpie test runs to actually inking skin. Aside from a lot of tongue-in-cheek trial and error, this project requires a sheer amount of problem-solving. [Emily] employs firmware edits to bypass safety checks, and clever hardware adaptations to ensure smooth transitions between strokes. One impressive upgrade is the emergency solenoid system, a literal panic button to stop the machine mid-tattoo in case of trouble—a critical addition for something with needles involved!

This hack sits on the edge of DIY body modification, raising eyebrows and technical questions alike. If you missed the warning and are now frantically searching for tattoo removal options, know we’ve covered some (but you might be rightfully scared of automating that, too, at this point). If you haven’t lifted a finger while reading this, just do the safe thing: watch [Emily]’s video, and tinker about the subsequent purposes this discovery creates for 3D printing or tattoo art.

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Tensegrity construction with Adafruit led strands

The Jell-O Glow Tensegrity Toy You Didn’t Know You Needed

If you’re looking to add a pop of glowing whimsy to your workspace, check out this vibrant jiggly desk toy by [thzinc], who couldn’t resist the allure of Adafruit’s NOODS LED strands. [thzinc]’s fascination with both glowing LEDs and levitating tensegrity designs led to an innovative attempt to defy gravity once again.

The construction’s genius is all about the balance of tension across the flexible LED strands, with three red ‘arms’ and a blue ‘hanger’ arm supporting the central hub. [thzinc]’s early designs faced print failures, but by cleverly reorienting print angles and refining channel designs, he achieved a modular, sturdy structure. Assembly involved careful soldering, tension adjustments, and even a bit of temporary tape magic to perfect the wobbling equilibrium.

But, the result is one to applaud. A delightful, wobbly desk toy with a kind of a Jell-O vibe that dances to your desk’s vibrations while glowing like a mini neon sign. We’ve covered tensegrity constructions in the past, so with a little digging through our archives you’ll be able to find some unique variations to build your own. Be sure to read [thzinc]’s build story before you start. Feel free to combine the best out there, and see what you can bring to the table!

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A dismantled drill on a cluttered workbench

Going Brushless: Salvaging A Dead Drill

Let’s face it—seeing a good tool go to waste is heartbreaking. So when his cordless drill’s motor gave up after some unfortunate exposure to the elements, [Chaz] wasn’t about to bin it. Instead, he embarked on a brave journey to breathe new life into the machine by swapping its dying brushed motor for a sleek brushless upgrade.

Things got real as [Chaz] dismantled the drill, comparing its guts to a salvaged portable bandsaw motor. What looked like an easy swap soon became a true hacker’s challenge: incompatible gear systems, dodgy windings, and warped laminations. Not discouraged by that, he dreamed up a hybrid solution: 3D-printing a custom adapter to make the brushless motor fit snugly into the existing housing.

The trickiest part was designing a speed control mechanism for the brushless motor—an impressively solved puzzle. After some serious elbow grease and ingenuity, the franken-drill emerged better than ever. We’ve seen some brushless hacks before, and this is worth adding to the list. A great tool hack and successful way to save an old beloved drill. Go ahead and check out the video below!

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Schematic of quantum measurement basis on whiteboard

Shedding Light On Quantum Measurement With Calcite

Have you ever struggled with the concept of quantum measurement, feeling it’s unnecessarily abstract? You’re not alone. Enter this guide by [Mithuna] from Looking Glass Universe, where she circles back on the concept of  measurement basis in quantum mechanics using a rather simple piece of calcite crystal. We wrote about similar endeavours in reflection on Shanni Prutchi’s talk at the Hackaday SuperConference in 2015. If that memory got a bit dusty in your mind, here’s a quick course to make things click again.

In essence, calcite splits a beam of light into two dots based on polarization. By aligning filters and rotating angles, you can observe how light behaves when forced into ‘choices’. The dots you see are a direct representation of the light’s polarization states. Now this isn’t just a neat trick for photons; it’s a practical window into the probability-driven nature of quantum systems.

Even with just one photon passing through per second, the calcite setup demonstrates how light ‘chooses’ a path, revealing the probabilistic essence of quantum mechanics. Using common materials (laser pointers, polarizing filters, and calcite), anyone can reproduce this experiment at home.

If this sparks curiosity, explore Hackaday’s archives for quantum mechanics. Or just find yourself a good slice of calcite online, steal the laser pointer from your cat’s toy bin, and get going!

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Going Minimal: 64×4, The Fun In Functional Computing

If you’ve ever wondered what makes a computer tick, the Minimal 64×4 by [Slu4] is bound to grab your attention. It’s not a modern powerhouse, but a thoughtfully crafted throwback to the essence of computing. With just 61 logic ICs, VGA output, PS/2 input, and SSD storage, this DIY wonder packs four times the processing power of a Commodore 64.

What sets [Slu4]’s efforts apart is his refusal to follow the beaten track of CPU development. He imposes strict complexity limits on his designs, sticking to an ultra-minimalist Von Neumann architecture. His journey began with the ‘Minimal Ur-CPU’, a logic-chip-based computer that could crunch numbers but little else. Next came the ‘Minimal 64’, featuring VGA graphics and Space Invaders-level performance. The latest ‘Minimal 64×4’ takes it further, adding incredible speed while keeping the design so simple it’s almost ridiculous. It’s computing stripped to its rawest form—no fancy sound, no dazzling graphics, just raw resourcefulness.

For enthusiasts of retro-tech and DIY builds, this project is a treasure trove. From text editors to starfield simulations to Sokoban, [Slu4] proves you don’t need complexity to make magic. Continue reading “Going Minimal: 64×4, The Fun In Functional Computing”

Photo of 3D Tetris LED matrix

From Retro To Radiant: 3D Tetris On A LED Matrix

We love seeing retro games evolve into new, unexpected dimensions. Enter [Markus]’ adaptation of 3D Tetris on a custom-built 3x3x12 RGB LED matrix. Developed as a university project, this open-source setup combines coding, soldering, and 3D printing. It’s powered by an ESP32 microcontroller with gameplay controlled by a neat web interface.

This 3D build makes the classic game so much harder to play, that one could argue whether it’s still a game, or has turned into a form of art. Although it is challenging to rotate and drop blocks on such a small scale, for die-hard Tetris fans (and we know you’re out there), there is always someone up to become best at it. Just look at the FastLED-powered light show, the responsive web-based GUI, and fully modular 3D printed housing, this project is a joy to look at even when nobody is playing it. Heck, a game that turned 40 only a year ago should be so mature to entertain itself, shouldn’t it?

From homemade Pong tables to LED cube displays, hobbyists keep finding ways to give classic games a futuristic twist. Projects like this are about pushing boundaries. Hackaday’s archives are full of similar innovations, but why not craft some new ones?

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