Motorized LEGO Train Gets Qi Charging In The Track

This project started, as many do, with a simple idea. [Ben Hoad] just wanted to take a static LEGO Hogwarts Express train kit and make it motorized. It was compatible with standard LEGO track pieces, so all he should have to do was figure out how to shoehorn a motor in there and be done with it. Right?

Well, you already know how things like this go. It started with adding the motor, which ended up being relatively straightforward once [Ben] used some community LEGO CAD tools to figure out which kits had the specific parts he needed to redesign the train in such a way that he’d have enough space inside for the motor without ruining the way it looked. But then the feature creep kicked in, and he found himself falling down that familiar rabbit hole.

A 3D representation of the train’s internal components.

The first problem was how to reliably power the train. It turns out the rear car was more or less empty already, so that became home for two 18650 batteries (the project details say “16850” but we believe that is merely a typo). [Ben] didn’t want to have to take the thing apart every time it ran down, so he wondered if it would be possible to add wireless charging.

A Qi coil in the bottom of the train car and one in a specially designed section of track got the power flowing, but getting them lined up proved a bit finicky. So he added a Hall effect sensor to the car and a strong magnet to the track, so the train would know when the coils were lined up and automatically pump the brakes.

So now he had a motorized train that could recharge itself, but how should he turn it on and off? Well, with an ESP8266 along for the ride, he figured it would be easy to add WiFi control. With a bit of code and the Homebridge project, he was able to get the train to appear as a smart switch to Apple’s HomeKit. That allows him to start and stop the train from his smartphone, complete with a routine that returns the train to the charging station once it’s finished making the rounds. [Ben] says the next steps are to put some sanity checks in, such as shutting the motors down if the train hasn’t passed the charging station in a few minutes; a sure sign that it’s not actually moving.

All [Ben] needs to do now is implement automatic LEGO train decoupling before the plastic Hogwarts students come back from spring break.

Lighting Up A Tiny Train Needs Tiny Tools

A tiny toy train that [voidnill] illuminated with a small LED strip fragment demonstrates several challenges that come with both modifying existing products, and working with small things in general. One is that it is hard in general to work around existing design choices and materials when modifying something. The second is that problems are magnified with everything is so small.

[voidnill]’s plentiful photos illustrate everything from drilling out small rivets and tapping the holes for screws to installing a tiny switch, LED strip, and button cells as a power supply. When things are so small, some of the usual solutions don’t apply. For example, cyanoacrylate glue may seem like a good idea for mounting small plastic parts, but CA glue easily wicks into components like the tiny power switch and gums up the insides, rendering it useless.

[voidnill] uses lots of careful cutting and patience to get everything done, and demonstrates the importance of quality tools. The LED strip fragment is driven by three small button cells, and while tape does a serviceable job as a battery holder, [voidnill] believes a 3D printed custom frame for the cells would really do the trick.

The kind of work that goes into making or modifying small things really puts into perspective the amount of effort behind projects like this coffee table with an N-gauge model railway inside it.

Vertical Train Hauls Up The Wall

Trains are great for hauling massive amounts of cargo from point A to point B, and occasionally, point C on weekends. But they’re not really known for climbing hills well, and anything vertical is right out. Regardless, [Can Altineller] knows what he wants and set to work, creating the 3D Printed Wall Train.

The first step was to get the train to stick to a vertical surface. This was achieved with the use of neodymium magnets in the train, which are attracted to laser-cut steel plates beneath the plastic tracks. The train itself consists of a custom 3D printed locomotive, outfitted with a motor and step-down gears that drive all four wheels. Said wheels are of a conical shape, and covered with rubber to provide enough grip to overcome gravity. The project is a progression from [Cal]’s earlier four-motor build.

The final result is a charming wall display, with the four-wheel drive train merrily tugging its carriages around the circular course ad infinitum. It’s a fun build, and we’d love to see similar techniques applied to a bigger layout. If this whets your appetite for model railroading, consider building your own turntable, or implementing some fancy sensors. Video after the break.

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A Tiny Train Departure Board, Just Like The Real Thing

If you travel on the British rail system, you’ll be familiar with the ubiquitous orange dot-matrix departure display boards. At a glance they tell you the expected arrival times of the next few trains, where they are headed, and at the bottom the current time.  [Chris Crocker-White] was inspired by a Tweet to recreate one of these displays in miniature and hang it under his monitor.

The hardware is a Raspberry Pi Zero with an OLED screen, in a custom 3D-printed case. A soldered USB cable takes power from the monitor’s USB ports. Software wise it’s a demonstration vehicle for the Balena cloud service that pulls its data from their transport API, but the choice of dot matrix typeface is perfect and absolutely looks the part.

There is some question as to whether a project such as this one should need a cloud service as its backend, and of course it serves as a demonstration piece rather than a definitive way to enact a departure board. It does however bring a ready-packaged API for transport data, which given that many data sources can be opaque, is a useful feature.

Train time displays seem to be a popular choice on the Eastern side of the Atlantic, here’s another British one, and one from Ireland.

Thanks [Pyrofer] for the tip.

To Make Reproduction Train Whistles, The Old Ways Are Best

Late last year, artist [Steve Messam]’s project “Whistle” involved 16 steam engine whistles around Newcastle that would fire at different parts of the day over three months. The goal of the project was bring back the distinctive sound of the train whistles which used to be fixture of daily life, and to do so as authentically as possible. [Steve] has shared details on the construction and testing of the whistles, which as it turns out was a far more complex task than one might expect. The installation made use of modern technology like Raspberry Pi and cellular data networks, but when it came to manufacturing the whistles themselves the tried and true ways were best: casting in brass before machining on a lathe to finish.

The original whistles are a peek into a different era. The bell type whistle has three major components: a large bell at the top, a cup at the base, and a central column through which steam is piped. These whistles were usually made by apprentices, as they required a range of engineering and manufacturing skills to produce correctly, but were not themselves a critical mechanical component.

In the original whistle shown here, pressurized steam comes out from within the bottom cup and exits through the thin gap (barely visible in the image, it’s very narrow) between the cup and the flat shelf-like section of the central column. That ring-shaped column of air is split by the lip of the bell above it, and the sound is created. When it comes to getting the right performance, everything matters. The pressure of the air, the size of the gap, the sharpness of the bell’s lip, the spacing between the bell and the cup, and the shape of the bell itself all play a role. As a result, while the basic design and operation of the whistles were well-understood, there was a lot of work to be done to reproduce whistles that not only operated reliably in all types of weather using compressed air instead of steam, but did so while still producing an authentic re-creation of the original sound. As [Steve] points out, “with any project that’s not been done before, you really can’t do too much testing.”

Embedded below is one such test. It’s slow-motion footage of what happens when the whistle fires after filling with rainwater. You may want to turn your speakers down for this one: locomotive whistles really were not known for their lack of volume.

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Low Tech High Safety And The NYC Subway System

The year is 1894. You are designing a train system for a large city. Your boss informs you that the mayor’s office wants assurances that trains can’t have wrecks. The system will start small, but it is going to get big and complex over time with tracks crossing and switching. Remember, it is 1894, so computing and wireless tech are barely science fiction at this point. The answer — at least for the New York City subway system — is a clever system of signals and interlocks that make great use of the technology of the day. Bernard S. Greenberg does a great job of describing the system in great detail.

The subway began operation in 1904, well over 30 years since the above-ground trains began running. A clever system of signals and the tracks themselves worked together with some mechanical devices to make the subway very safe. Even if you tried to run two trains together, the safety systems would prevent it.

On the face of it, the system is very simple. There are lights that show red, yellow, and green. If you drive, you know what these mean. But what’s really interesting is the scheme used at the time to make them light.

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Hackaday Visits The Electric City

Much to the chagrin of local historians, the city of Scranton, Pennsylvania is today best known as the setting for the American version of The Office. But while the exploits of Dunder Mifflin’s best and brightest might make for a good Netflix binge, there’s a lot more to the historic city than the fictional paper company. From its beginnings as a major supplier of anthracite coal to the introduction of America’s first electrically operated trolley system on its streets, Scranton earned its nickname “The Electric City” by being a major technological hub from the Industrial Revolution through to the Second World War.

Today, the mines and furnaces of Scranton lie silent but not forgotten. In the 1980’s, the city started turning what remained of their industrial sites into historic landmarks and museums with the help of State and Federal grants. I recently got a chance to tour some of these locations, and came away very impressed. They’re an exceptional look into the early technology and processes which helped turn America into an industrial juggernaut.

While no substitute for visiting these museums and parks for yourself, hopefully the following images and descriptions will give you an idea of what kind of attractions await visitors to the modern day Electric City.

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