Solving A Rubik’s Cube With Just Two Motors

December 2, 2017 by Dan Maloney 11 Comments

We’ve all seen videos of Rubik’s cube champions who can solve the puzzle in less than 5 seconds. And there are cube-twisting robots that can solve the cube even faster, often in under a second. This Rubik’s cube solver is not one of those robots, but it’s still pretty cool.

The reason we like Dexter Industries’ “BricKuber” is not for its lightning speed — it takes a minute or two to solve the puzzle. What we like is the simplicity of the approach to manipulating the cube. Built from LEGO parts, including Mindstorms motors and a BrickPi controller, the BricKuber uses only two motors to work the cube. One motor powers a square turntable upon which the cube sits, while the other powers an arm that does double duty — it either clamps the cube so the turntable can rotate a layer, or it rakes the cube to flip it 90° on the turntable. With a Pi Cam overhead, the rig images all six faces, calculates a solution to the cube, and then flips and twists the cube to solve it. It’s simultaneously mind-boggling and strangely relaxing to watch.

All the code is open source, and we strongly suspect a similar and possibly faster robot could be built without the LEGO parts. You might even be able to build one with popsicle sticks and an Arduino.

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Lego Go-Kart Scores Radio Control

December 1, 2017 by Lewin Day No comments

LEGO has always been an excellent toy for both play and learning, and the Technic sets are a great starting point for any budding engineer. Not content to rest on their plastic, blocky laurels, LEGO introduced more advanced parts over the years, such as motors and battery packs to allow builders to propel their creations. Combine this mechanical philosophy with [Matt]’s Giant Lego Go-Kart and you have one heck of a project.

It all started months ago, when [Matt] built his original Giant Lego Go-Kart, a 5-times scaled up model of the original kit #1972-1. Achieved through the wonder of 3D printing, he had sized it up based off the largest parts he could fit on his printer. The Youtube video led to commenters asking – could it be driven?

He decided that radio control was definitely a possibility. Not content to simply bolt on a series of motors to control the drive and steering, he took the effort to build scaled up replica LEGO motors, even taking care to emulate the old-school connectors as well. A particularly nice touch was the LEGO antenna, concealing the Orange RX radio receiver.

There were some hiccups – at this scale & with [Matt]’s parts, the LEGO force just isn’t strong enough to hold everything together. With a handful of zipties and a few squirts of glue, however, the giant ‘kart was drifting around the carpark with ease and hitting up to 26km/h.

In the end, the build is impressive not just for its performance but the attention to detail in faithfully recreating the LEGO aesthetic. As for the next step, we’d like to know what you think – how could this be scaled up to take a human driver? Is it possible? You decide.

Functioning Technic SLJ900 Bridge Builder

November 22, 2017 by John Baichtal 9 Comments

There is definitely a passion for detail and accuracy among LEGO builders who re-create recognizable real-world elements such as specific car models and famous buildings. However, Technic builders take it to a level the regular AFOLs cannot: Not only must their model look like the original, it has to function the same way. Case in point, [Wolf Zipp]’s version of a massive bridge-building rig. The Chinese-built SLJ900 rolls along the tops of bridges and adds ginormous concrete spans with the aplomb found only in sped-up YouTube videos. It is nevertheless a badass robot and a worthy target for Technicization.

[Wolf]’s model is 2 meters long and weighs 10.5kg, consisting of 13 LEGO motors and a pneumatic rig, all run by a handheld control box. The rig inserts LEGO connectors to a simulated bridge span, lifts it up, moves it over the next pier, then drops it down into place. The span weighs 2.5kg by itself — that ain’t no styrofoam! There are a lot of cool details in the project. For instance, the mechanism that turns the wheels for lateral movement consists of a LEGO-built pneumatic compressor that trips pneumatic actuators that lift the wheels off the ground and allows them to turn 90 degrees.

Sometimes it blows the mind what can be built with Technic. Check out this rope-braiding machine and this 7-segment display we’ve posted. Continue reading “Functioning Technic SLJ900 Bridge Builder” →

Mechanical Marvel Trades Courage For Chocolate

October 30, 2017 by Steven Dufresne 4 Comments

When we see what [Jason Allemann] does with LEGO, we wonder why more one-offs aren’t made this way. This time he’s made a Halloween mechanical marvel that will surely scare more kids than anything else they’ll encounter on their rounds — so much so that many may even decline the chocolate it dispenses. Who wouldn’t when to get it you have to reach over an animatronic skeleton hand that may grab you while a similarly mechanized spider may lunge onto your hand.

The chocolate dispensing, the hand and the spider are all animated using four motors, a LEGO Mindstorms EV3 brick to control them, and a touch sensor. When a kid presses a pumpkin attached to the touch sensor, the next chocolate candy is lowered by gravity onto a conveyor belt and carried forward to the awaiting child. That much is automatic. At the discretion of [Jason] and his partner [Kristal], using an infrared remote control and sensor, they can activate the skeleton hand and the lunging spider at just the right moment. We’re just not sure who they’ll choose to spare. It is Halloween after all, and being scared is part of the fun, so maybe spare no one? Check out the video below and tell us if you’d prefer just the treat, or both the trick and treat.

We do have to wonder if there’s any project that can’t benefit from LEGO products, even if only at the prototype stage or to help visualize an idea. As a small sample, [Jason]’s also made a remote-controlled monowheel and an actual working printer along with a Morse key telegraph machine to send it something to print.

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Enlarged Miniature Forklift

October 19, 2017 by Brian McEvoy 19 Comments

How do you classify something that is gigantic and miniature at the same time? LEGO kit 850, from 1977 when it was known as an Expert Builder set, was 210 modular blocks meant to be transformed into a forklift nearly 140mm tall. [Matt Denton] scaled up the miniature pieces but it still produced a smaller-than-life forklift. This is somewhere in the creamy middle because his eight-year-old nephew can sit on it but most adults would demolish their self-esteem if they attempted the same feat.

[Matt] has been seen before building these modular sets from enlarged LEGO blocks, like his Quintuple-Sized Go-Kart. He seems to have chosen the same scale for the pieces and who wouldn’t? If you’re printing yourself a ton of LEGO blocks, it just makes sense to keep them all compatible. Isn’t combing all your sets into one mishmash the point after all? We’ll see what his nephew/co-host constructs after his uncle [Matt] leaves.

In the time-lapse video after the break, you can see how the kit goes together as easily as you would hope from home-made bricks. With that kind of repeatability and a second successful project, it’s safe to say his technique is solid and this opens the door to over-sized projects to which LEGO hasn’t published instructions.

Hackaday is bursting with LEGO projects, K’Nex projects, and even Erector set projects.

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LEGO Row Boat Is The Poolside Companion You Didn’t Know You Needed

October 15, 2017 by Tom Nardi 9 Comments

Maybe it’s the upbeat music, or the views of a placid lake at sunset, or perhaps it’s just seeing those little plastic rods pumping away with all their might. Whatever the reason may be, the video [Vimal Patel] posted of his little remote controlled LEGO row boat cruising around on the open water is sure to put a smile on the face of even the most jaded hacker.

[Vimal] tells us that his creation is made up of over 140 unmodified LEGO parts, and is controlled over Bluetooth which connects to an app on his phone. While we would like to see some more detail on the reciprocating module he came up with to drive the boat’s paddles, we have to admit that the images he provided in his flickr album for the project are impeccable overall. If the toy boat game doesn’t work out for [Vimal], we think he definitely has what it takes to get into the advertising department for a car manufacturer.

[Vimal] was even kind enough to provide a LEGO Digital Designer file for the project, which in the world of little rainbow colored blocks is akin to releasing the source code, so you can build up your own fleet before next summer.

It’s worth noting that [Vimal] is something of a virtuoso in the world of modular building blocks, and no stranger here at Hackaday. His self lacing shoe impressed earlier this year, and this isn’t even his first LEGO watercraft.

All he has to do now to reach the true pinnacle of LEGO construction is to start building with giant versions of everyone’s favorite block.

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LEGO-compatible Electronics Kits Everywhere!

October 12, 2017 by Bob Baddeley 19 Comments

Within the last few years, a lot of companies have started with the aim to disrupt the educational electronics industry using their LEGO-compatible sets. Now they’re ubiquitous, and fighting each other for their slice of space in your child’s box of bricks. What’s going on here?

Raison D’Être

The main reason for LEGO-compatibility is familiarity. Parents and children get LEGO. They have used it. They already have a bunch. When it comes to leveling up and learning about electronics, it makes sense to do that by adding on to a thing they already know and understand, and it means they can continue to play with and get more use from their existing sets. The parent choosing between something that’s LEGO-compatible and a completely separate ecosystem like littleBits (or Capsela) sees having to set aside all the LEGO and buy all new plastic parts and learn the new ecosystem, which is a significant re-investment. littleBits eventually caught on and started offering adapter plates, and that fact demonstrates how much demand there is to stick with the studs.

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