Air Bubble Characters Float Along This Unique Scrolling Display

November 30, 2018 by 16 Comments

We’ve seen a lot of unique large-format scrolling message boards on these pages, but most of them use some sort of established technology – LEDs, electromechanical flip-dots, and the like – in new and unusual ways. We’re pretty sure this air-bubble dot matrix display is a first, though.

While it may not be destined for the front of a bus or a train station arrivals and departures board, [jellmeister]’s bubble display shows some pretty creative thinking. It started with a scrap of multiwall polycarbonate roofing – Corotherm is the brand name – of the type to glaze greenhouses and other structures. The parallel tubes are perfect for the display, although individual tubes could certainly be substituted. A plastic end cap was fabricated; air nozzles in each channel were plumbed to an air supply through solenoid valves. An Arduino with a couple of motor driver hats allows pulses of air into each channel to create reasonably legible characters that float up the tube. The video below shows it in use at a Maker Faire, where visitors could bubble up their own messages.

It took some tweaking to get it looking as good as it does, but there’s plenty of room for improvement. We wonder whether colored liquid might help, or perhaps adding a Neopixel or even a laser to each channel to add some contrast. Maybe something to cloud the water slightly would help; increasing the surface tension with a salt solution might make the bubbles more distinct. We doubt it’ll ever have the contrast ratio of a flip-dot display, but it certainly has a charm all its own.

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Collecting, Repairing, And Wearing Vintage Digital Watches

November 28, 2018 by 91 Comments

Electronics enthusiasts have the opportunity to be on the very cusp of a trend with vintage digital watches (VDW). Vintage digital watches are those watches that from the late 70’s and throughout the 80’s. They’re unlike any watch style today, and for anyone around when they made their debut these deliver a healthy dose of nostalgia.

Monetarily speaking, it is not worth the money to pay a watch maker to restore a digital watch but for those of us with basic electronics skills we can put the time and effort into making them run again and be one of the few in possession of functioning VDW. It’s a statement as well as a sign of your own aptitude.

Earlier this year, Steven Dufresne walked us through the history of the digital watch. In this article we will dive into the world of vintage digital watch repair.

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DIY Ovalia Chair Serves Your Futuristic Fantasies

November 25, 2018 by 16 Comments

The 1960s were a heady time, with both society and the language of design undergoing rapid changes over a short period. Back in 1968, Henrik Thor-Larsen exhibited his Ovalia egg chair for the first time, at the Scandinavian Furniture Fair. With original examples now antiques, and with even replicas being prohibitively expensive, it might just be worth considering building your own if you need to have one. Thankfully, [Talon Pascal] leads the way.

It’s a replica that’s built with accessible DIY tools and techniques. The frame is built up from plywood parts, cut out with a jigsaw. These are then assembled with glue and screws, forming two halves of the full-sized egg assembly. The exterior is then covered with thin strips of wood, as opposed to the fiberglass construction of the original. This is smoothed out with a judicious application of wood putty and plenty of sanding. The interior is then lined with foam before the chair is upholstered with red fabric. We’re not sure exactly how the trim ring is fitted, but it gives the chair a nice clean finished edge and rounds out the project nicely. There are even embedded speakers so you can chill out with some tunes in your ovaloid sanctuary.

It just goes to show that there’s value in the old adage – if you can’t buy it, build it! Perhaps, however, you’re outfitting the office – in which case, would something from the Porsche range suffice?

Mining Airport WiFi Data: This Sunday Is The Worst Day To Fly

November 24, 2018 by 6 Comments

This is Thanksgiving weekend in the United States; the country’s most congested travel weekend of the year. It’s common knowledge, and it’s easy to infer that this holiday weekend is one of the busiest for air travel. But can you prove it empirically? Apparently so. [Bertrand Fan] filed a Freedom of Information Act request for the WiFi traffic at San Francisco International Airport and used the access point data from the past year and a half to show which days were most congested in the airport.

FOIA actually has its own website which boils down the act as follows:

The basic function of the Freedom of Information Act is to ensure informed citizens, vital to the functioning of a democratic society.

We’re not sure if this particular data mining hack falls under that description, but it’s good to know if you want information about what government is doing, you can get it and fast! From the first request to receiving the info was just 10 days.

Ghostscript was used to turn the PDF into a CSV which was then plotted on a graph. It shows that the heaviest WiFi usage was on 11/26/17, the Sunday after Thanksgiving. As you can see, the only thing returned was data used per day for each SSID (plus dates which aren’t shown in this screenshot). But in theory the more people stuck at the airport the more data they’ll consume, so the method is reasonable.

This was all just to color a conversation he was having with his parents about the weekend’s travel. It’s a long way to go to prove a point, but we had fun joining along in the ride!

[via Lobsters]

Foam Airboat Is Cheap RC Fun

November 15, 2018 by 7 Comments

Archer fans and residents of Louisiana will already be familiar with the concept of the airboat. Put a powerful engine running an aircraft prop on a flat-bottomed hull, and you’ve got an excellent way to traverse the marshes of the American South. While a fully-fledged airboat might run you the best part of $100,000, this no-frills radio-controlled version is great fun at a much lower price.

The hull is built on a sheet of foam, which is cheap, readily available, and suitably buoyant for the task. It’s then kitted out with a brushless motor to run the prop and a servo to control the rudder. Lace it up with a radio receiver and speed controller and you’re good to go.

The build could readily be completed in well under a couple of hours, and is a great one to tackle with kids due to its mechanical simplicity. There’s room for extra creativity too – you can always substitute a watermelon if you’re feeling peckish. Video after the break. Continue reading “Foam Airboat Is Cheap RC Fun” →

Tilt-Rotor Plane Needs Flight Controller Hack To Get Airborne

November 6, 2018 by 6 Comments

Part of the charm of quadcopters is the challenge that building and flying them presents. In need of complex sensors and computational power to just get off the ground and under tremendous stresses thanks to their massively powerful motors, they often seem only barely controlled in flight. Despite these challenges, quadcopter flight has been reduced to practice in many ways, leaving hobbyists in search of another challenge.

[Tom Stanton] is scratching his creative itch with this radio-controlled tilt-rotor airplane that presents some unique problems and opportunities. Tilt-rotor planes are, as the name implies, able to swivel their propellors and transition them from providing forward thrust to providing verticle lift. With the rotors providing lift, the aircraft is able to hover and perform vertical take-off and landing (VTOL); switched to thrust mode, wings provide the lift for horizontal flight.

[Tom]’s realization of this design seems simple – a spar running through the wing holding BLDC motors and props is swiveled through 90° by a servo to transition the aircraft. Standard control surfaces on the wings and tail take care of horizontal flight. Actually getting an off-the-shelf flight controller to deal with the transitions was tricky. [Tom] ended up adding an Arduino to intercept the PWM signals the flight controller normally sends directly to the servos and speed controls to provide the coordination needed for a smooth transition. Full details in the video below, and some test flights which show that an RC VTOL is anything but a beginner’s plane.

[Tom] is proving himself to be quite the Renaissance man these days. Between air-powered piston engines, over-balance trebuchets, and popping the perfect wheelie, he seems to have covered all the bases and done his best to keep our tip line stocked.

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Teardown And Repair Of A Police Recorder

November 2, 2018 by 9 Comments

You should probably hope you haven’t seen [Techmoan’s] cassette recorder before. That’s because it is a Neal interview recorder that was mainly used by police to tape interrogations. This one was apparently used by the Royal Navy and was sold for parts. Turns out, the repair was simple, but the teardown and the analysis of the machine — you can see it in the video below — is pretty interesting if you’ve never seen one of these before.

The unit looks like a heavy-duty piece of industrial electronics from the 1980s. Unlike a commercial tape deck, this one is made to do one thing: record. You can’t even rewind a tape in it. Also unlike a consumer recorder, the Neal has a few special features aimed at making sure you didn’t miss some important confession on tape. First, it beeps if there’s no microphone plugged in. When [Techmoan] showed the recording head, we noticed it looked like it was split in half. Towards the end of the video, we found out why. In addition, the unit records two tracks: one audio track and another with a voice reading the elapsed time every 10 seconds — pretty high tech for its day.

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