Testing Various Properties Of LEGO-Compatible Axles

November 14, 2023 by 9 Comments

If you ever wondered what’d happen if you were to use LEGO Technic parts, but they were made out of something other than plastic, the [Brick Experiment Channel] has got you covered. Pitting original Lego axles against their (all except steel commercially available) equivalents made out of carbon fiber, aluminium and steel, some of the (destructive) results are very much expected, while some are more surprising.

Lego-compatible axle test results. (Credit: Brick Experiment Channel, YouTube)

Starting off with the torque test, each type of axle is connected with others and rotated with increasing torque until something gives out. Unsurprisingly, the plastic Technic part fails first and renders itself into a twist, before the carbon fiber version gives up. Aluminium is softer than steel, so ultimately the latter wins, but not before a range of upgrades to the (LEGO-based) testing rig, as these much stronger axles require also strong gears and the like to up the torque.

When it comes to durability, all except the original LEGO version didn’t mind having plastic rubbing against them for a while. Yet for friction in general, the plastic version did better, with less friction. Whether or not this is due to material wearing away is a bit of a question. Overall, stainless steel gets you a lot of strength, but in a dense (8000 kg/m3) package, aluminium comes somewhat close, with 2700 kg/m3, and carbon fiber (1500 kg/m3) does better than the original part (1400 kg/m3), with only a bit more weight, though at roughly ten times the cost.

On that note, we’re looking forward to the first 100% stainless steel LEGO Technic kit, reminiscent of the era when Meccano came in the form of all-metal components and a bucket of bolts.

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3D Printing LEGO-like Blocks

June 10, 2023 by 8 Comments

LEGO are perhaps the perfect children’s toy, at least until you step on the errant brick while walking around the house. Available in all kinds of sets with varying themes and characters, they encourage building and creativity in kids like no other. Those with 3D printers might have considered creating their own specialty blocks, but the manufacturing of real LEGO blocks involves steel molds with extremely tight tolerances far outside the realm of most 3D printers. To print blocks capable of interconnecting in a similar way involves taking advantage of the characteristics of 3D printers and their materials instead, as [CNC Kitchen] demonstrates with these PrintABloks.

The PrintABlok was the idea of [Joe Larson] aka [3D Printing Professor] and is built around a one-unit base block, which has holes on all of its sides, paired with small connecting pieces which are placed in the holes to connect the various blocks to one another. Using your CAD software of choice (although they were originally built using Blender), the base block can be lengthened or widened for printing various different types of blocks, and the diamond-shaped hole can even be added to various prints that aren’t blocks at all. This means that a wide variety of parts can be made, all designed to interlock with the bricks or various other shapes. [Joe] even created an array of themed sets like robots, castles, and dinosaurs and although he sells these more complex models, he released his base set and interconnection mechanism for free and is available for anyone to use.

Another perk of the PrintABlok system is that they are scalable, mitigating safety risks for smaller children that might try to swallow some of the smaller parts. It’s an excellent way to put the 3D printer to work if there are any children around in the house. But this isn’t the only LEGO-inspired build we’ve ever seen, and they aren’t always going to be used to make children’s toys. [Ivan] recently used similar 3D-printed interlocking bricks more in the style of LEGO Technic to attempt to build a human-rideable go-kart.

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Lego Guitar Is Really An Ultrasonically-Controlled Synth

January 26, 2023 by 4 Comments

The phrase “Lego Guitar” can be a stressful one to hear. You might imagine the idea of strings under tension and a subsequently exploding cloud of plastic shrapnel. This build from the [Brick Experiment Channel] eschews all that, thankfully, and is instead a digital synth that only emulates a guitar in its rough form factor.

The heart of the build is a Lego Mindstorms EV3 controller. It’s acts as the “body” of the guitar, and is fitted with a Lego “fretboard” of sorts. A slide is moved up and down the fretboard by the player. The EV3 controller detects the position of the slide via an ultrasonic sensor, and uses this to determine the fret the user is trying to play. The button the user presses on the controller then determines which of five “strings” the user is playing, and the selected note is sounded out from the EV3’s internal speaker. It’s strictly a monophonic instrument, but three different sounds are available: a bass guitar, a rock guitar, and a solo guitar, with all the fidelity and timbre of a 90s Casio keyboard.

It’s a fun and silly instrument, and also kind of difficult to play. The slide mechanism doesn’t offer much feedback, nor are the EV3 buttons intended for dynamic musical performance. Regardless, the player belts out some basic tunes to demonstrate the concept. We doubt you’d ever be able to play Through The Fire and Flames on such a limited instrument, but [Brick Experiment Channel] used their editing skills to explore what that might sound like regardless.

We’ve seen some other great synth guitars before, too. Modern microcontrollers and electronics give makers all kinds of creative ways to build electronic instruments with unique and compelling interfaces. Some are more successful than others, but they’re all fun to explore. Video after the break.

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Gaze Upon The Swimming Mechanical Stingray, Made With LEGO

December 10, 2022 by 5 Comments

Stingrays have an elegant, undulating swimming motion that can be hypnotic. [Vimal Patel] re-created this harmony with his fantastic mechanical mechanical stingray using LEGO pieces and a LEGO Technics Power Functions motor. The motor is set in a clever arrangement that drives the motion remotely, so that it and electrical elements can stay dry.

The mechanical stingray sits at the end of a sort of rigid umbilical shaft. This shaft connects the moving parts to the electrical elements, which float safely on the surface. This leaves only the stingray itself with its complex linkages free to move in the water, while everything else stays above the waterline.

We’ve seen some impressive LEGO creations before, like this race car simulator and pneumatic engine, and the mechanical action in this stingray is no exception. Interested in making your own? The part list and build directions are available online, and you can see it in action in the video embedded below.

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Blender Builds LEGO Models

November 15, 2022 by 13 Comments

Blender is a free and open source computer graphics package that’s used in the production of everything from video games to feature films. Now, as demonstrated by [Joey Carlino], the popular program can even be used to convert models into LEGO.

This new feature available in Blender 3.4 allows for the use of instance attributes in a way that a large number of points on a model can be created without causing undue strain on (and possible crashing of) the software. Essentially, an existing model is split into discrete points at specific intervals. The spacing of the intervals is set to be exactly that of LEGO bricks, which gives the model the low-resolution look of a real LEGO set. From there, a model brick is created and placed at each of these points, and then colors can be transferred to the bricks individually.

The demonstration that [Joey] uses is converting a beach ball model to LEGO, but using these tools on other models delivers some striking results. He goes over a lot of the details on how to create these, and it would only be a short step from there to ordering the bricks themselves. Or, using these models and sending them over to a 3D printer straight from Blender itself. Not bad for free software!

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End Of An Era, As LEGO To Discontinue Mindstorms

November 3, 2022 by 46 Comments

When there are so many single board computers and other products aimed at providing children with the means to learn about programming and other skills, it is easy to forget at time before the Arduino or the Raspberry Pi and their imitators, when a computer was very much an expensive closed box.

Into this late-’90s vacuum left in the wake of the 8-bit home computer revolution came LEGO’s Mindstorms kits, a box of interlocking goodies with a special programmable brick, which gave kids the chance to make free-form computerized robotic projects all of their own. The recent news that after 24 years the company will discontinue the Mindstorms range at the end of the year thus feels like the end of an era to anyone who has ridden the accessible microcontroller train since then.

What became Mindstorms has its roots in the MIT Media Lab’s Programmable Brick project, a series of chunky LEGO bricks with microcontrollers and the Mindstorms LEGO brick contacts for motors and sensors. Their Logo programming language implementation was eschewed by LEGO in favor of a graphical system on a host computer, and the Mindstorms kit was born. The brand has since been used on a series of iterations of the controller, and a range of different robotics kits.

In 1998, a home computer had morphed from something programmable in BASIC to a machine that ran Windows and Microsoft Office. Boards such as Parallax’s BASIC Stamp were available but expensive, and didn’t come with anything to control. The Mindstorms kit was revolutionary then in offering an accessible fully programmable microcontroller in a toy, along with a full set of LEGO including motors and sensors to use with it.

We’re guessing Mindstorms has been seen off by better and cheaper single board computers here in 2022, but that doesn’t take away its special place in providing ’90s kids with their first chance to make a proper robot their way. The kits have found their place here at Hackaday, but perhaps most of the projects we’ve featured using them being a few years old now underlines why they are to meet their end. So long Mindstorms, you won’t be forgotten!

Header image: Mairi, (CC BY-SA 3.0).

A Lego cup holder with a glass of water and electronics on a breadboard

LEGO Cup Holder Helps You To Stay Hydrated

January 4, 2022 by 11 Comments

Eat more fruit, exercise more, drink more fluids; early January is traditionally the time to implement New Year’s resolutions. Most of the common ones simply require willpower, but if it’s staying hydrated that you’re targeting, then some help is available. [Pepijn de Vos] designed a LEGO cup holder and an accompanying desktop app that tell you exactly how much water you’ve had so far, making it easier to get to those eight glasses a day.

The basic idea is simple: the cup holder contains a load cell that senses the weight of your drinking vessel. If the weight decreases, then a message is sent to your PC detailing the amount lost. If the weight increases, then the glass must have been refilled and the previous weight is disregarded. This way, the app simply needs to add up all the amounts reported, without having to compensate for the weight of the empty glass.

The tricky bit was integrating a load cell into the LEGO structure. It required some fiddling with Flex System hoses to ensure the platform’s weight rested only on the load cell, while still being stable enough to safely hold a full glass of water. The load cell is read out through an amplifier and A/D converter, while the USB communication is handled by a Teensy 3.

[Pepijn] modified an existing GNOME desktop widget to display a cup icon and the total volume consumed, which seems to work pretty smoothly judging from the video embedded below. All the code and even a complete set of LEGO build instructions are available on the project’s Github page. If simply monitoring your fluid intake isn’t enough of a nudge for you, then check out this device that floods your desk if you don’t drink enough.

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