3D Printed Magnetic Switches Promise Truly Custom Keyboards

January 17, 2022 by Jenny List 57 Comments

While most people are happy to type away at whatever keyboard their machine came with, for the keyboard enthusiast, there’s no stone to be left unturned in the quest for the perfect key switch mechanism. Enter [Riskable], with an innovative design for a 3D printed mechanism that delivers near-infinite adjustment without the use of springs or metallic contacts.

The switching itself is performed by a Hall effect sensor, the specifics of which are detailed in a second repository. The primary project simply represents the printed components and magnets which make up the switch mechanism. Each switch uses three 4 x 2 mm magnets, a static one mounted on the switch housing and two on the switch’s moving slider. One is mounted below the static magnet oriented to attract it, while the other is above and repels it.

With this arrangement the lower magnet provides the required tactility, while the upper one’s repulsive force replaces the spring used in a traditional mechanism. [Riskable] calls it the magnetic separation contactless key switch, but we think “revolutionary” has a nicer ring to it.

The part which makes this extra-special is that it’s a fully parametric OpenSCAD model in which the separation of the magnets is customisable, so the builder has full control of both the tactility and return force of the keys. There’s a video review we’ve posted below that demonstrates this with a test keypad showing a range of tactility settings.

We have a resident keyboard expert here at Hackaday in the shape of our colleague [Kristina Panos], whose Keebin’ With Kristina series has introduced us to all that is interesting in the world of textual input. She plans on taking a keyboard made of these clever switches on a test drive, once she’s extruded the prerequisite number of little fiddly bits.

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A Dodgy Dial Gets A Teardown And Some Oil

January 16, 2022 by Jenny List 8 Comments

The pulse-dial telephone and its associated mechanical exchange represents the pinnacle of late-19th and early-20th century electromechanical technology, but its vestiges have disappeared from view with astonishing rapidity. [Matthew Harrold] is a telecoms enthusiast who’s been kind enough to share with us the teardown and refurbishment of that most signature of pulse-dial components, a telephone dial. In this case it’s on a rather unusual instrument, a British GPO outdoor phone that would have been seen in all kinds of industrial and safety installations back in the day and can probably still be found in the wild today if you know where to look.

The teardown soon identifies a dial that runs very slowly and is sorely in need of a clean. There follows a detailed part-by-part dismantling of the dial mechanism, followed by a careful clean, polish, and reassembly. He notes that a previous owner had used grease to lubricate it, probably the reason for its slow operation.

The result is a smoothly running dial and a refurbished phone that would probably last another half-century or more before needing more maintenance. It’s enough to make others who’ve experimented with pulse dial phones very envious.

Four Wheel Steering, Always The Option, Never The Defining Feature

January 13, 2022 by Jenny List 67 Comments

A couple of weeks ago when it emerged that a new Tesla might have a four-wheel steering capability, our colleague Dan Maloney mused aloud as to how useful a four-wheel steering system might be, and indeed whether or not one might be necessary at all. This is hardly the first time four-wheel steering has appeared as the Next Big Thing on the roads. It’s time to take a look at the subject and ask whether it’s an idea with a future, or set to go the way of runflat tyres as one of those evergreen innovations that never quite catches on.

What’s your dream vehicle? If you’re like me, you have more than one. There in my lottery-winner’s garage, alongside the trail bikes and the mobile hackerspace, the dictator-size Mercedes and the Golf Mk1, will be a vehicle that by coincidence has four-wheel steering. The JCB Fastrac is a tractor that can travel across almost any terrain at full speed, and though I have no practical use for one and will never own one, I have lusted after one of these machines for over three decades. Their four-wheel steering system is definitely unusual, but that makes it the perfect vehicle with which to demonstrate four-wheel steering. Continue reading “Four Wheel Steering, Always The Option, Never The Defining Feature” →

Work The World On A 555

January 13, 2022 by Jenny List 14 Comments

Over the years the humble 555 timer has been used in so many unexpected places, but there’s a project from [Frank Latos] which we think may be a first. On a piece of stripboard sit a pair of 555s, and instead of the usual passives there are a set of LC circuits. This is no timer, instead it’s a CW (Morse) transmitter for the 80 metre amateur radio band.

One 555 is configured as a feedback oscillator through a toroidal transformer with a tuned circuit to set the frequency of oscillation. The other takes an inverted input from the oscillator to produce complimentary push-pull outputs from both 555s, which are fed to another transformer that in turn feeds a low-pass filter and thus the antenna.

Free-running squarewave oscillators of this type are not unusual for the lower HF bands, but we think this is the first 555 design we’ve seen. As shown it doesn’t produce much in the way of RF power, but remembering half-decent motor drivers using a 556 dual timer we think that selection of one of the more powerful 555 variants might deliver some more punch. We commend his creativity though, and hope he can get that all-important entry in the log to prove it works.

If you’re curious about low-power radio operation, it’s something we’ve explored before.

CEEFAX Lives! (Courtesy Of A Raspberry Pi)

January 7, 2022 by Jenny List 28 Comments

As analogue TV slides from memory, there’s a facet of it that’s fondly remembered by a band of enthusiasts. Teletext was an electronic viewdata information service digitally encoded in the frame blanking period, and a TV set with a decoder chip would provide access to many pages of news and other services all displayed in the characteristic brightly colored block graphics. It went the way of the dinosaur with the demise of analog TV, but for [Nathan Dane] the flame is kept alive with his own private version of the BBC’s CEEFAX service.

He has a particular enthusiasm for analog TV, and as such has his own in-house channel served by a UHF modulator. He shares with us the story of how he arrived at a teletext service, before writing code to scrape the BBC news and weather websites and populate his modern-day CEEFAX. Behind it all is a Raspberry Pi, with a vbit-pi board injecting the teletext signal onto the video, and raspi-teletext creating the pages from source material derived from a set of custom scraper scripts.

We like this project a lot, because while it’s not the first Pi teletext system we’ve encountered, the use of a scraped live feed makes it one of the most creative.

Thanks [kwikius] for the tip!

The Cucumber House That LEGO Built

January 4, 2022 by Jenny List 19 Comments

How far are you prepared to go to build a novelty seasonal ornament? Maybe a gingerbread house, or perhaps a bit of 3D printed glitter to hang on your Christmas tree. For [The Brick Wall], none of this was enough. Instead what was needed was a complete LEGO automated factory that builds a log cabin, from the unlikely raw material of cucumbers.

What has been created is the LEGO equivalent of a timber mill, with the various machines served by an overhead gantry crane. The cucumbers are trimmed to square, before being transferred to a saw which cuts out the notches for the interlocking corners. Another saw line chops the sections around door and windows to length, and finally the roof planks are cut in a vertical saw. The video below is reported as taking 83 days to complete from planning to filming, and 18 cucumbers to build the house. We’re not sure the cucumber will become a regular building material, but we salute the effort involved here.

Though this may be one of the biggest we’ve seen, we’ve featured many LEGO machines making things before.

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Genius Or Cursed, This USB-C Connector Is Flexible

January 1, 2022 by Jenny List 18 Comments

USB connectors have lent themselves to creative interpretations of their mechanical specifications ever since the first experimenter made a PCB fit into a USB-A socket. The USB-C standard with its smaller connector has so far mostly escaped this trend, though this might be about to change thanks to the work of [Sam Ettinger]. His own description of his USB-C connector using a flexible PCB and a BGA-packaged ATTiny84A microcontroller is “cursed”, but we can’t decide whether or not it should also be called “genius”.

Key to this inspired piece of connector fabrication is the realization that the thickness of BGA and flex PCB together comes to the required 0.7 mm. The BGA provides the necessary stiffness, and though it’s a one-sided connector it fits the space perfectly. There are several demo boards as proofs-of-concept, and the whole lot can be found in a GitHub repository.

We can see this technique finding a use in all kinds of diminutive USB-C projects, however cursed or genius it may be. We like to see projects that push the edges of what can be done with the medium, with a nod to a previous cursed USB-C device.

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