Retrotechtacular: A Very British MagLev

March 6, 2018 by Jenny List 54 Comments

When we look back to the 1970s it is often in a light of somehow a time before technology, a time when analogue was still king, motor vehicles had carburettors, and telephones still had rotary dials.

In fact the decade had a keen sense of being on the threshold of an exciting future, one of supersonic air travel, and holidays in space. Some of the ideas that were mainstream in those heady days didn’t make it as far as the 1980s, but wouldn’t look out of place in 2018.

The unlikely setting for todays Retrotechtacular piece is the Bedford Levels, part of the huge area of reclaimed farmland in the east of England known collectively as the Fens. The Old Bedford River and the New Bedford River are two straight parallel artificial waterways that bisect the lower half of the Fens for over 20 miles, and carry the flood waters of the River Ouse towards the sea. They are several hundred years old, but next to the Old Bedford River at their southern end are a few concrete remains of a much newer structure from 1970. They are all that is left of a bold experiment to create Britain’s first full-sized magnetic levitating train, an experiment which succeeded in its aim and demonstrated its train at 170 miles per hour, but was eventually canceled as part of Government budget cuts.

A track consisting of several miles of concrete beams was constructed during 1970 alongside the Old Bedford River, and on it was placed a single prototype train. There was a hangar with a crane and gantry for removing the vehicle from the track, and a selection of support and maintenance vehicles. There was an electrical pick-up alongside the track from which the train could draw its power, and the track had a low level for the hangar before rising to a higher level for most of its length.

After cancellation the track was fairly swiftly demolished, but the train itself survived. It was first moved to Cranfield University as a technology exhibit, before in more recent years being moved to the Railworld exhibit at Peterborough where it can be viewed by the general public. The dream of a British MagLev wasn’t over, but the 1980s Birmingham Airport shuttle was hardly in the same class even if it does hold the honour of being the world’s first commercial MagLev.

We have two videos for you below the break, the first is a Cambridge Archaeology documentary on the system while the second is a contemporary account of its design and construction from Imperial College. We don’t take high-speed MagLevs on our travels in 2018, but they provide a fascinating glimpse of one possible future in which we might have.

It does make one wonder: will the test tracks for Hyperloop transportation break the mold and find mainstream use or will we find ourselves 50 years from now running a Retrotechtacular on abandoned, vacuum tubes?

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One Man’s Quest For A Desktop Spherical Display

March 5, 2018 by Tom Nardi 20 Comments

[Nirav Patel] is a man on a mission. Since 2011 he has been obsessed with owning a spherical display, the kind of thing you see in museums and science centers, but on a desktop scale. Unfortunately for him, there hasn’t been much commercial interest in this sort of thing as of yet. Up to this point, he’s been forced to hack up his own versions of his dream display.

That is until he heard about the Gakken Worldeye from Japan. This device promised to be exactly what he’s been looking for all these years, and he quickly snapped up two of them: one to use, and one to tear apart. We like this guy’s style. But as is often the case with cheap overseas imports, the device didn’t quite live up to his expectations. Undaunted by the out of the box performance of the Worldeye, [Nirav] has started documenting his attempts to improve on the product.

These displays work by projecting an image on the inside of a frosted glass or plastic sphere, and [Nirav] notes that the projection sphere on the Worldeye is actually pretty decent. The problem is the electronics, namely the anemic VGA resolution projector that’s further cropped down to a 480 pixel circle by the optics. Combined with the low-quality downsampling that squashes down the HDMI input, the final image on the Worldeye is underwhelming to say the least.

[Nirav] decided to rip the original projector out of the Worldeye and replace it with a Sony MP-CL1 model capable of a much more respectable 1280×720. He came up with a 3D printed bracket to hold the MP-CL1 in place, and has put the files up on Thingiverse for anyone who might want to play along at home. The results are better, but unfortunately still not great. [Nirav] thinks the sphere is physically too small to support the higher resolution of the MP-CL1, plus the optics aren’t exactly of the highest quality to begin with. But he’s just glad he didn’t have to build this one from scratch.

Going back to our first coverage of his DIY spherical display in 2012, we have to say his earliest attempts are still very impressive. It looks like this is a case of the commercial market struggling to keep up with the work of independent hackers.

Controlling OctoPrint On The Go

March 5, 2018 by Tom Nardi 33 Comments

Not too long ago I took the plunge into the world of OctoPrint by shoehorning a Raspberry Pi Zero into a PrintrBot Play, and I have to say, the results were quite impressive. OctoPrint allows you to run your 3D printer untethered from your computer, but without all the downsides of printing off of an SD card. Generally running off of a Raspberry Pi, OctoPrint serves up a very capable web interface that gives you full control over slicing and printing from essentially any device with a modern browser.

That’s all well and good if you’ve got your laptop with you, or you’re sitting at your desktop. But what if you’re out of the house? Or maybe out in the garage where you don’t have a computer setup? OctoPrint is still happily serving up status information and a control interface, you just don’t have a computer to access it. Luckily, there are options for just that scenario.

In this post we’re going to take a look at a couple of options for controlling and monitoring OctoPrint from your mobile device, which can help truly realize its potential. Personally I have an incredible amount of anxiety when leaving a 3D printer running a long job, and in the past I’ve found myself checking every 10 minutes or so to see if it was done. Now that I can just glance at my phone and see an ETA along with status information about the machine, it’s given me the confidence to run increasingly longer and complex prints. Continue reading “Controlling OctoPrint On The Go” →

Badgelife: From 1 To 100

March 5, 2018 by Brian Benchoff 11 Comments

Blame it on the falling costs of printed circuit boards, the increased accessibility of hardware design tools, the fact that GCC works on microcontrollers now, whatever the ‘maker movement’ is, or any one of a number of other factors. There’s a hardware demoscene now. Instead of poking bits, writing code, and dividing by zero to create impressive multimedia demonstrations on a computer, there is a small contingent of very creative people who are building their own physical hardware, just for the hell of it. They’re pushing boundaries of what can be done with hardware design, demonstrating manufacturing know-how, and turning a (small) profit while doing it. This is badgelife, the tiny subculture dedicated to creating custom electronic conference badges.

At Hackaday, we’ve been doing a deep dive into the rigors of this demoscene of hardware, and last week we had the pleasure of hosting a meetup with some of the big players of the badgelife community as guests of honor. There were, of course, talks discussing the trials and tribulations of designing, manufacturing, and shipping hundreds of pieces of hardware on a limited budget with not enough time. If you want to know how hard electronic design and manufacturing can be, you want to check out these talks below. Continue reading “Badgelife: From 1 To 100” →

FPGA Makes ASCII Video

March 5, 2018 by Al Williams 28 Comments

Human beings like pictures which is probably why there’s the old adage “A picture’s worth a thousand words.” We take computer graphic output for granted now, but even in the earliest days for Teletypes and line printers, there was artwork made from characters ranging from Snoopy to Spock. [Wenting Z] continues the tradition by creating an FPGA that converts VGA video to ASCII art and outputs it via DVI.

The device uses a Xilinx Virtex device and uses about 500 LUT (look up tables) which is not much at all. You can see a video (that includes an overlay of the source video) of the device in action below.

In fact, we think of art like this as a computer phenomenon, but [Flora Stacey] created a butterfly on a typewriter in 1898 and ham radio operators were doing art using paper tape for the last half of the twentieth century. Even before that, In 1865, Alice in Wonderland had a certain passage that was typeset to suggest a mouse’s tail. Perhaps the pinnacle is the famous ASCII version of Star Wars.

This is decidedly less mechanical than some of the other ASCII art projects we’ve seen. If you have a taste for more text art, have a look at some other examples, including a very old advertisement that uses character art.

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Unionize Your Variables – An Introduction To Advanced Data Types In C

March 2, 2018 by Sven Gregori 61 Comments

Programming C without variables is like, well, programming C without variables. They are so essential to the language that it doesn’t even require an analogy here. We can declare and use them as wildly as we please, but it often makes sense to have a little bit more structure, and combine data that belongs together in a common collection. Arrays are a good start to bundle data of the same type, especially when there is no specific meaning of the array’s index other than the value’s position, but as soon as you want a more meaningful association of each value, arrays will become limiting. And they’re useless if you want to combine different data types together. Luckily, C provides us with proper alternatives out of the box.

This write-up will introduce structures and unions in C, how to declare and use them, and how unions can be (ab)used as an alternative approach for pointer and bitwise operations.

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Mechanisms: The Reed Switch

March 1, 2018 by Kristina Panos 75 Comments

Just about everywhere you go, there’s a reed switch nearby that’s quietly going about its work. Reed switches are so ubiquitous that you’re probably never more than a few feet away from one at any given time, especially at home or in the car. You might have them on your doors and windows as part of a burglar alarm system. They keep your washing machine from running when the lid is open, and they put your laptop to sleep when you close the lid. They know if the car has enough brake fluid and whether or not your seat belt is fastened.

Reed switches are interesting devices with a ton of domestic and industrial applications. We call them switches, but they’re also sensors. In fact, they only do the work of a switch while they can sense a magnetic field. They are capable of switching AC or DC at low and high voltages, but they don’t need electricity to work. Since they’re sealed in glass, they are impervious to dirt, dust, corrosion, temperature swings, and explosive environments. They’re cheap, they’re durable, and in low-current applications they can last for about a billion actuations.

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