LDU Decoded: The Untold Tale Of LEGO Dimensions

December 27, 2024 by Heidi Ulrich 11 Comments

LEGO bricks might look simplistic, but did you know there’s an actual science behind their sizes? Enter LDUs — LEGO Draw Units — the minuscule measurement standard that allows those tiny interlocking pieces to fit together seamlessly. In a recent video [Brick Sculpt] breaks down this fascinating topic.

So, what is an LDU precisely? It’s the smallest incremental size used to define LEGO’s dimensions. For context, a standard LEGO brick is 20 LDUs wide, and a single plate is 8 LDUs tall. Intriguingly, through clever combinations of headlight bricks, jumper plates, and even rare Minifig neck brackets, builders can achieve offsets as tiny as 1 LDU! That’s the secret sauce behind those impossibly detailed LEGO creations.

We already knew that LEGO is far more than a toy, but this solidifies that theory. It’s a means of constructing for anyone with an open mind – on its own scale. The video below explains in detail how to achieve every dimension possible. If that inspires you to build anything, dive into these articles and see if you can build upon this discovery!

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students overlooking their rope-traversing robots

Crawler Challenge: Building Rope-Traversing Robots

December 23, 2024 by Heidi Ulrich 4 Comments

Rope-climbing robots are the stuff of engineering dreams. As kids, didn’t we all clutter our family home with constructions of towers and strings – Meccano, or Lego – to have ziplines spanning entire rooms? Good for the youngsters of today, this has been included in school curricula. At the University of Illinois, the ME 370 students have been given the task of building a robot that can hang from a rope and walk across it—without damaging the rope. The final projects show not only how to approach tricky design problems, but also the creative solutions they stumbled upon.

Imagine a tiny, rope-climbing walker in your workshop—what could you create?

The project is full of opportunities for those thinking out of the box. It’s all about the balance between innovation and practicality: the students have to come up with a solution that can move at least 2 meters per minute, fits in a shoebox, and has some creative flair—no wheels allowed! The constraints provide an extra layer of challenge, but that’s where the fun lies. Some students use inverted walkers, others take on a more creature-like approach. The clever use of motors and batteries shows just how far simple tech can go when combined with a bit of engineering magic.

This project is a fantastic reminder that even small, seemingly simple design challenges can lead to fascinating creations. It invites us adults to play, and by that, we learn: a win-win situation. You can find the original article here, or grab some popcorn and watch the video below.

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Rudolph’s Sleigh On A North Pole PCB

December 20, 2024 by Heidi Ulrich 18 Comments

Each Christmas, [Adam Anderson], [Daniel Quach], [Johan Wheeler], and [Gustav Abrahamsson] (going by ‘the Janky Jingle Crew’)—set themselves the challenge of outdoing their previous creations. Last year’s CH32 Fireplace brought an animated LED fire to life with CH32V003 microcontrollers.

This year, they’ve gone a step further with the North Pole Circuit, a holiday project that combines magnetic propulsion, festive decorations, and a bit of engineering flair. Inspired by a miniature speedway based on Friedrich Gauss’ findings, the North Pole Circuit includes sleighs and reindeer that glide along a custom PCB track, a glowing village with flickering lights, and a buzzer to play Christmas tunes.

The propulsion system works using the Lorentz force, where vertical magnets interact with PCB traces to produce motion. A two-phase design, similar to a stepper motor, ensures smooth operation, while guard rails maintain stability on curves. A separate CH32V003 handles lighting and synchronized jingles, creating a cohesive festive display. As we mentioned in the article on their last year’s creation, going from a one-off to a full batch will make one rethink the joy of repetitive production. Consider the recipients of these tiny Christmas cards quite the lucky ones. We deem this little gift a keeper to put on display when Christmas rolls around again.

This annual tradition highlights the Crew’s knack for combining fun and engineering. Curious about the details or feeling inspired to create your own? Explore the full details and files on their GitHub.

3D Printed Blaster Does It With Compliant Components

December 17, 2024 by Donald Papp 20 Comments

The ease of integrating bendy parts into designs is one of 3D printing’s strengths. A great example of this is [uhltimate]’s six-shot blaster which integrates several compliant mechanisms. The main blaster even prints in one piece, so there’s not even any assembly required.

The ergonomics are unconventional, but the design is pretty clever.

The blaster itself has three main parts: the trigger, the sear, and the striker. Each of them rely on compliant mechanisms in order to function. The user pulls back the trigger, which hooks into and pulls back the striker. When the trigger is pulled back far enough, the sear releases the striker. This zips forward and slams into a waiting projectile, sending it flying.

The other interesting part is the projectiles and magazine in which they sit. The magazine fits onto the front of the blaster and pulling the trigger allows the magazine to drop down, putting the next projectile into firing position. After the final round is fired, the empty magazine falls away. It’s a pretty clever design, even if the ergonomics are a little unusual and it relies on gravity in order to feed. Tilt it too far sideways or upside down, and it won’t load properly.

We’ve seen compliant mechanisms used for projectile firing before, but this design really raises the bar in the way it does more than just firing the striker.

3D printing allows rapid iteration of designs, which makes devices that rely on compliant mechanisms much easier to develop and fine-tune.

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Walkie Talkies, Jedi Style: Building A Communicator

December 13, 2024 by Heidi Ulrich 6 Comments

Playing Star Wars Outlaws sparked an idea with [3DSage]: why not recreate the game’s wrist communicator as a functioning gadget? Inspired by the relatively simplistic design, he and his friend Ben set out to build their own device to take to Galaxy’s Edge in Disneyland. Armed with an arsenal of tools—3D printers, CNC machines, and soldering irons—he aimed to turn imagination into reality.

After ordering multiple walkie-talkies, they meticulously tested each one for audio quality, circuit board size, and compatibility with custom components. The ‘world’s tiniest walkie-talkie’ had potential but demanded creative modifications, including disassembling and resoldering components. They crafted their own circuit board and designed a 3D printed housing to fit both electronics and style. For the finishing touch, they weathered the device with paints and even glow-in-the-dark accents, making it authentic to the Star Wars universe. Even Chewbacca himself gave one a thumbs-up!

Weathering goes a long way towards creating a convincing prop — it can turn a bundle of pipes and some foam blocks into a movie-ready WWII machine gun.

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Tiny PONG, Big Ambitions: World’s Smallest Arcade

December 11, 2024 by Heidi Ulrich 5 Comments

London, Ontario college student [Victoria Korhonen] has captured the attention of tech enthusiasts and miniaturization lovers with her creation of what might be the world’s smallest arcade machine. Standing just 64 mm tall, 26 mm wide, and 30 mm deep, this machine is a scaled-down marvel playing the classic Atari game PONG. While the record isn’t yet official—it takes about three months for Guinness to certify—it’s clear [Korhonen]’s creation embodies ingenuity and dedication.

[Korhonen], an electromechanical engineering student, took six months to design and build this micro arcade. Inspired by records within reach, she aimed to outdo the previous tiniest arcade machine by shaving off just a few millimeters During the project she faced repeated failures, but viewed each iteration as a step towards success. Her miniature machine isn’t just a gimmick; it’s fully functional, with every component—from paddle mechanics to coding—developed from scratch.

[Korhonen] is already eyeing new projects, including creating the smallest humanoid robot. She also plans to integrate her electromechanical expertise into her family’s escape room business. Her journey aligns with other hobbyist projects pushing the limits of miniaturization, such as this credit card-sized Tetris clone or [Aliaksei Zholner]’s paper micro engines.

Do 3D Printers Dream Of LEGO Sheep?

December 9, 2024 by Heidi Ulrich 21 Comments

Imagine the power to clone your favorite LEGO piece—not just any piece, but let’s say, one that costs €50 second-hand. [Balazs] from RacingBrick posed this exact question: can a 3D scanner recreate LEGO pieces at home? Armed with Creality’s CR-Scan Otter, he set out to duplicate a humble DUPLO sheep and, of course, tackle the holy grail of LEGO collectibles: the rare LEGO goat.

The CR-Scan Otter is a neat gadget for hobbyists, capable of capturing objects as small as a LEGO piece. While the scanner proved adept with larger, blocky pieces, reflective LEGO plastic posed challenges, requiring multiple scans for detailed accuracy. With clever use of 3D printed tracking points, even the elusive goat came to life—albeit with imperfections. The process highlighted both the potential and the limitations of replicating tiny, complex shapes. From multi-colored DUPLO sheep to metallic green dinosaur jaws, [Balazs]’s experiments show how scanners can fuel customization for non-commercial purposes.

For those itching to enhance or replace their builds, this project is inspiring but practical advice remains: cloning LEGO pieces with a scanner is fun but far from plug-and-play. Check out [Balazs]’s exploration below for the full geeky details and inspiration.

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