Decoupling Lego Trains Automatically

Lego train sets were introduced almost 50 years ago, and since then, one thing has been constant: the trains connected with magnets. While this is a supremely simple means of connecting locomotives to rolling stock, there is one big disadvantage. Building decouplers – devices that will separate one car from another – is difficult.

Now, with a clever combination of racks, gears, and wedges, trains can disassemble themselves. They can even do it with an Arduino.

wedgeThis decoupler works by effectively wedging cars apart from each other. With a motor from an old Lego Technic set, a few gears, shafts, and a rack, a device can be constructed that fits between the rails of a track that raises into the undercarriage of rolling stock.

Because this rolling stock is moved around with a locomotive, all that’s needed to separate two halves of a train is to move the locomotive forward. Yes, it does mean that the connection with the weakest magnet is disengaged – not necessarily the connection you want to decouple. However, with only one car and a locomotive, there’s only one connection to break. Simple enough.

This Lego decoupler can be further improved with an Arduino, a few ultrasonic sensors, and an IR detector to make a fully automatic decoupling siding for a Lego train layout. You can see all this below operating with a full state machine that perpetually switches rolling stock behind a locomotive.

A great use for Legos.

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Hackaday Links: December 6, 2015

[Camus] had it all wrong. After a few hundred years of rolling a stone up a mountain, Sisyphus would do what all humans would do: become engrossed in novelty. The stone would never reach the summit, but it could roll off some pretty sweet ramps. That mountain goat that ticked him off a few decades ago? If Sisyphus let go right now, the stone would probably take that goat out. Sisyphus, like all of us, would be consumed in meaningless novelty. One must imagine Sisyphus happy.

The pumpkin spice must flow. It’s the holidays and for a lot of us that means copious amounts of baked goods. How about an edible sandworm? It looks like something close to a cinnamon roll.

This December’s Marie Claire – whatever that is, I have no idea – features haute circuits. These circuit boards are the work of [Saar Drimer] and Boldport, makers of fine circuit board art. We’ve seen his work a number of times featuring squiggly traces and backlit panels. This seems to be the first time Boldport and the entire idea of PCB art has infiltrated the design world. He also does puzzles.

Raspberry Pi cases simply do not look cool. There’s ports coming out everywhere, and plastic really doesn’t look that great. You know what does look great? Walnut. [Karl] made a few of these out of walnut, MDF and solid aluminum. He’s thinking he might bring this to market, you can check out his webzone here.

Self-driving cars being sold right now! That’s an eBay link for a DARPA Grand Challenge vehicle, a heavily modified Isuzu VehiCross loaded up with computers, a laser scanner, camera, and connected to actuators for steering, brake, pedals, and shifter.

A few years ago, a snowboarding company realized they could use YouTube as a marketing device. They made some really cool projects, like a snowboard with battery-powered heaters embedded in the core of the board (yes, it works). There’s only so many different snowboards you can build, so they turned to surfboards. In fact, they turned to cardboard surfboards, and last week they made a cardboard electric guitar in the Fender custom shop. It’s a completely understandable linear progression from A to B to I don’t know what kind of glue they’re using.

DIY Lego Slit-Scan 2001 Stargate

[Filmmaker IQ] has a bunch of great tutorials on the technical aspects of making movies, but this episode on copying the stargate Stanley Kubrick’s famous 2001: A Space Odyssey using Legos is a hacker’s delight.

The stargate in 2001 is that long, trippy bit where our protagonist Dave “I’m sorry Dave” Bowman gets pulled through space and time into some kind of alternate universe and is reborn as the star child. (Right, the plot got a little bit bizarre.) But the stargate sequence, along with the rest of the visual effects for the film, won them an Academy Award.

Other examples of slit scan animations you’ll recognize include the opening credits for Doctor Who and the warp-drive effect in Star Trek: TNG.

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Optics Laboratory Made From LEGO

16A lot of engineers, scientists, builders, makers, and hackers got their start as children with LEGO. Putting those bricks together, whether following the instructions or not, really brings out the imagination. It’s not surprising that some people grow up and still use LEGO in their projects, like [Steve] who has used LEGO to build an optics lab with a laser beam splitter.

[Steve] started this project by salvaging parts from a broken computer projector. Some of the parts were scorched beyond repair, but he did find some lenses and mirrors and a mystery glass cube. It turns out that this cube is a dichroic prism which is used for combining images from the different LCD screens in the projector, but with the right LEGO bricks it can also be used for splitting a laser beam.

The cube was set on a LEGO rotating piece to demonstrate how it can split the laser at certain angles. LEGO purists might be upset at the Erector set that was snuck into this project, but this was necessary to hold up the laser pointer. This is a great use of these building blocks though, and [Steve] finally has his optics lab that he’s wanted to build for a while. If that doesn’t scratch your LEGO itch, we’ve also featured this LEGO lab which was built to measure the Planck constant.

Lego Printer Prints Lego

[Gosse Adema] made his very first instructable by detailing his Lego 3D printer build. It’s Prusa i3 based, and originally started out as an A4 plotter with repurposed steppers out of an old HP printer. After upgrading to some NEMA 17 steppers, it became a full-blown 3D printer.

It turns out that NEMA 17 stepper mounting holes align perfectly with Lego, making it super easy to mount them. Check out this Lego ‘datasheet’ for some great details on measurements.

The brains of the printer are occupied by Marlin running atop a Atmega 2560, and Pronterface for the PC software. He tops it off with a Geeeteck built MK8 extruder boasting a 0.3 mm nozzle that accepts 1.75 mm filament.

As with almost any DIY 3D printer build, his first prints didn’t turn out so well. After adjusting the nozzle and filament size in the software, he started to get some good results. Be sure to check out the video below to see this Lego 3D printer in action.

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Large NES Controller Made From LEGOs

If LEGO are cool, and abnormally large NES controllers are cool, then what [Baron von Brunk] has created is pretty dang cool. It’s a super large functional NES game controller…. made out of LEGO! Yes, your favorite building blocks from the past (or present) can now be use to make an unnecessarily large game controller.

lego-nes-internalsThe four main sides of the controller case are standard stacked grey LEGO bricks. The inside of the case is mostly hollow, only with some supporting structures for the walls and buttons. The top is made from 4 individual LEGO panels that can be quickly and easily removed to access the interior components. The large LEGO buttons slide up and down inside a frame and are supported in the ‘up’ position care of some shock absorbers from a Technic Lego set. The shocks create a spring-loaded button that, when pressed down, makes contact with a momentary switch from Radio Shack. Each momentary switch is wired to a stock NES controller buried inside the large replica. The stock controller cord is then connected to an NES-to-USB adapter so the final product works with an NES Emulator on a PC.

[Baron von Brunk] is no stranger to Hackaday or other LEGO projects, check out this lamp shade and traffic light.

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“Bricking” Microcontrollers in LEGO Motivates Young Programmers

Back when he was about seven years old, [Ytai] learned to program on an Atari 800XL. Now he has a seven-year-old of his own and wants to spark his interest in programming, so he created these programmable LEGO bricks with tiny embedded microcontrollers. This is probably one of the few times that “bricking” a microcontroller is a good thing!

IMG_20150519_144818The core of the project is the Espruino Pico microcontroller which has the interesting feature of running a Java stack in a very tiny package. The Blocky IDE is very simple as well, and doesn’t bog users down in syntax (which can be discouraging to new programmers, especially when they’re not even a decade old). The bricks that [Ytai] made include a servo motor with bricks on the body and the arm, some LEDs integrated into Technic bricks, and a few pushbutton bricks.

We always like seeing projects that are geared at getting kids interested in creating, programming, and hacking, and this certainly does that! [Ytai] has plans for a few more LEGO-based projects to help keep his kid interested in programming as well, and we look forward to seeing those! If you’re looking for other ways to spark the curiosity of the youths, be sure to check out the Microbot, or if you know some teens that need some direction, perhaps these battlebots are more your style.