Miniature Concrete Hoover Dam Is Tiny Engineering Done Right

April 21, 2023 by Lewin Day 13 Comments

Growing up, we got to play with all kinds of things in miniature. Cars, horses, little LEGO houses, the lot. What we didn’t get is a serious education with miniature-sized dams. This recreation of the glorious Hoover Dam from the [Creative Construction Channel] could change all that for the next generation.

The build starts with the excavation of a two-foot long curve in a replica riverbed. A cardboard base is installed in the ditch, and used as a base for vertical steel wires. Next, the arch of the dam is roughed out with more steel wires installed horizontally to create a basic structure. The cardboard is then be removed from the riverbed, with the steel structure remaining. It’s finally time to pour real concrete, with a foundation followed by the main pour into foam formwork. The dam is also given 3D printed outlets that can be opened to allow water to pass through — complete with small gear motors to control them. The structure even gets a little roadway on top for good measure.

The finished product is quite impressive, and even more so when the outlets open up to spill water through. Such a project would be great fun for high school science students, or even engineering undergrads. Who doesn’t want to play with a miniature scale dam, after all? Bonus points if you build an entire LEGO city downstream, only to see it destroyed in a flood.

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Rubik’s Cube Solver Does It In 4.56 Seconds

April 2, 2023 by Lewin Day 14 Comments

Solving Rubik’s Cubes is a learnable skill. However, to compete at the top level, you’ll have to train hard. Speed cubers can solve a 3×3 cube in under ten seconds these days, after all. [aaedmusa] was a long way off that speed, but his robot is an absolute demon that solves at a rapid pace.

The robot relies on a Teensy 4.1 microcontroller to run the show, paired with its Ethernet kit for connectivity. It runs six stepper motors via TMC2208 drivers, enabling it to directly actuate each face of the cube. Purists will note, however, that the steppers are fitted with adapters that slot directly into modified center squares on the cube. A regulation Rubik’s, this is not.

The design doesn’t feature a machine vision system to capture the state of the cube. Instead, the cube’s status must be input to a web app on an attached computer. Once the cube’s state is loaded into the program, though, the mechanical job of solving the cube can be achieved in under five seconds. Even with six actuators, that’s not fast enough to beat the human world record of 3.47 seconds, but it’s still pretty darn good.

It’s funny to think that way back in 2011, both robots and humans were so much slower at solving cubes. If only all the world’s problems were as simple as a jumbled up toy from the 1970s.

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Magic 8 Ball Provides Tech Support

March 28, 2023 by Bryan Cockfield 15 Comments

ChatGPT might be making the news these days for being able to answer basically any question it’s asked, those of us who are a little older remember a much simpler technology that did about the same thing. The humble “Magic 8 Ball” could take nearly the same inputs, provided they were parsed in simple yes/no form, and provide marginal help similar to the AI tools of today. For a toy with no battery or screen, this was quite an accomplishment. But the small toy couldn’t give specific technical support help, so [kodi] made one that can.

The new 8 Ball foregoes the central fluid-filled chamber for an STM32 Blue Pill board with a few lithium batteries to power it. The original plastic shell was split in two with a hacksaw and fitted with a 3D printed ring which allows the two halves to be reconnected and separated again when it needs to charge. It uses a circular OLED to display the various messages of tech support, which are displayed when an accelerometer detects that the toy has been shaken.

Granted, most of the messages are about as helpful to solving a tech support issue as the original magic 8 Ball’s would have been, but we appreciate the ingenuity and carefree nature of a project like this. It also did an excellent job at operating in a low-power state as well, to avoid needing to charge it often. There have been a few other digital conversions of these analog fortune tellers as well, like this one which adds GIFs to each of the original answers.

A LEGO Camera You Just Might Own Yourself

March 25, 2023 by Jenny List 6 Comments

A camera makes for an interesting build for anyone, because it’s an extremely accessible technology that can be made from materials as simple as cardboard. More robust cameras often require significant work, but what if you could make a usable camera from LEGO? It’s a project taken on by [Zung92], who hasn’t simply made a working 35 mm camera from everyone’s favorite construction toy — he’s also managed to make it exude retro style. Best of all, you can vote for it on the LEGO Ideas website, and you might even get the chance to have one for yourself.

Frustratingly there’s little in the way of in-depth technical detail on the Ideas website, but he does mention that it was a challenge to make it light proof. Even the lens is a LEGO part, and if diffraction-based photography isn’t for you there’s also a pinhole option. We look forward to seeing this camera progress, and we hope we’ll see it advance to becoming a LEGO Ideas kit.

This is an extremely polished design, but surprisingly, it’s not our first LEGO camera.

Thanks [Michael] for the tip.

Working Artificial Horizon Built Into A Single LEGO Brick

March 20, 2023 by Lewin Day 16 Comments

Back in the day, LEGO spaceship sets used to come with these little wedge blocks painted with fake gauges on them. [James “Ancient” Brown] decided that wasn’t good enough. Thus, he took everything he needed for a functional artificial horizon, and stuffed it inside a single LEGO brick. Yes, it’s real, and it’s spectacular.

We featured [James’] electronics-infused bricks some time ago when they first hit the Internet. The basic story is that he managed to cram an OLED screen and an RP2040 into a silicone mold for a LEGO-compatible brick. His first iterations stunned the world, as they ran pretty monochrome animations that brought life to formerly-inanimate chunk of plastic.

Since then, [James] has been busy. He’s managed to squeeze an accelerometer into the brick form factor as well. That allowed him to build a LEGO piece which displays an impressively-smooth artificial horizon display, as you might find in an aircraft. He demonstrates this by putting the instrument on a LEGO craft and zooming it around the room. All the while, the artificial horizon accurately tracks the motions of the craft.

It’s an impressive build, and something we’d love to see included in future LEGO vehicles…even if they’re just 3D renders. Continue reading “Working Artificial Horizon Built Into A Single LEGO Brick” →

DOOM Ported To A Single LEGO Brick

March 18, 2023 by Lewin Day 18 Comments

By now you’ve all seen the tiny LEGO brick with a working screen in it. The work of one [James “Ancient” Brown], it was truly a masterpiece of miniaturization and creativity. Since then, [James] hasn’t stopped innovating. Now, he’s demoing a playable version of DOOM running on a single plastic brick.

We’ve covered the construction of these astounding screen bricks before. Long story short, [James] designed a tiny PCB that hosts an RP2040 microcontroller which is then hooked up to a tiny OLED screen. The components are placed in a silicone mold, which is then filled with transparent resin to form the brick. The screen is then powered via contacts in the bottom, much like older-style LEGO motors.

Early experiments involved running various graphics to emulate a spaceship dashboard, but [James] has now gone much further. He’s implemented RP2040-doom to run the game. It uses tilt controls thanks to an accelerometer, combined with capacitive touch controls for shooting. The monochrome OLED is driven very fast with a special library of [James’] own creation to create three levels of grayscale to make the game actually visible and (just barely) playable.

It’s a hack, of course, and the controls are far from perfect. Nobody’s speed-running E1M1 on [James’s] LEGO brick, to be sure. Perchance. With that said, it’s still a glorious piece of work nonetheless. Just imagine, sitting with friends, and announcing you’re going to play some DOOM — only to pluck a piece of LEGO out of your pocket and start blasting away at demons.

Just because [James] doesn’t know when to quit, we’re going to lay down the gauntlet. Let’s get network play happening on these things, yeah?
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Modded See ‘N Say Teaches The Sounds Of City Life

March 13, 2023 by Tom Nardi 19 Comments

The Fisher-Price See ‘n Say was introduced back in 1964, and since then has helped teach countless children the different sounds made by farm animals. But what about our urban youth? If they’re going to navigate a concrete jungle, why not prepare them to identify the sound of a jackhammer or the chime that plays before an announcement goes out over the subway’s PA system?

That’s the idea behind this hacked See ‘n Say [John Park] put together for Adafruit. Now we should note up front that no vintage toys were sacrificed during the production of this gadget — it seems Fisher-Price (predictably) dropped the tiny record player these toys used to use for a cheap electronic board sometime in the 90s. A quick check with everyone’s favorite A-to-Z megacorp shows you can pick up one of these new-school models for around $25 USD.

The modern electronic version of the toy is easy to mod.

Cracking open the electronic version of the See ‘n Say reveals a circular PCB with a series of membrane buttons that are pressed by the mechanics of the spinning pointer. As it so happens, there are handy test points next to each of these buttons, which makes it simple to wire up to a microcontroller.

In this case, it’s Adafruit’s KB2040, which is connected to a MAX98357A amplifier board over I2S. A small boost converter module is used to wring 5 volts out of the toy’s pair of AA batteries. The original speaker is repurposed, though [John] adds a physical power switch to keep the boost converter from flattening the alkaline batteries when not in use.

On the software side, all you’ve got to do is load the MCU with your sounds and write a bit of code that associates them with the button being pressed on the PCB. [John] gets his city sounds from Freesound, a community-maintained database of Creative Commons Licensed sounds, and provides the CircuitPython code necessary to tie everything together.

The last step is the artwork. For this project, [Brian Kesinger] provided some swanky vintage-looking imagery that perfectly fits the See ‘n Say style. The art is available under the NonCommercial-ShareAlike Creative Commons license, so you’re free to use it in your own version. Though naturally, that assumes you’ve decided to use the same sounds as [John] — the beauty of this project is that you could easily load it up with whatever sounds you’d like Hacker Junior to learn. Possibly a well-known Australian YouTuber?

If anyone feels inclined to build a Hackaday-themed See ‘n Say based on this project, we’ve love to see it.

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