Vintage Aircraft Controls Turned USB Button Box

July 25, 2020 by Tom Nardi 4 Comments

The Gables Engineering G-2789 audio selector panels aren’t good for much outside of the aircraft they were installed in, that is, until [MelkorsGreatestHits] replaced most of the internals with a Teensy 3.2. Now they are multi-functional USB input devices for…well, whatever it is you’d do with a bunch of toggle switches and momentary push buttons hanging off your computer.

With the Teensy going its best impression of a USB game controller, the host operating system has access to seven momentary buttons, twelve toggles, and one rotary axis for the volume knob.

Right now [MelkorsGreatestHits] says the code is set up so the computer sees a button press on each state change; in other words, the button assigned to the toggle switch will get “pressed” once when it goes up and again when it’s flicked back down. But of course that could be modified depending on what sort of software you wanted to interface the device with.

As we’ve seen with other pieces of vintage aircraft instrumentation, lighting on the G-2789 was provided by a series of incandescent bulbs that shine through the opaque front panel material. [MelkorsGreatestHits] replaced those lamps with white LEDs, but unfortunately the resulting light was a bit too harsh. As a quick fix, the LEDs received a few coats of yellow and orange paint until the light was more of an amber color. Using RGB LEDs would have been a nice touch, but you work with what you’ve got.

This isn’t the first time that [MelkorsGreatestHits] has turned an old aircraft cockpit module into a USB input device, and we’re certainly interested in seeing what the next project will look like. Though we’re perhaps more interested in finding out where all all these old school airplane parts are coming from…

3D Printed Doggie Braces

July 25, 2020 by Orlando Hoilett 2 Comments

[Tye’s] dog Lucifur unfortunately has degenerative arthritis causing her a lot of pain in her feet. The vet suggested orthotic carpal braces to help alleviate the pain, but they come at a price tag of at least $1600. Given her current budgetary limitations, [Tye] decided to try the DIY route.

The first task was to cast Lucifur’s paws in plaster to make a mold of her feet in both the weight-bearing and non-weight-bearing orientations. According to [Tye], the non-weight-bearing orientation is more representative of the shape of a “normal” paw, but she also needed to model the weight-bearing orientation to better design the braces for walking.

Then it was time to print a PLA-based dog splint from a design she found on Thingiverse. Since PLA softens when it’s in boiling water, the splint can be easily molded to Lucifur’s paw. This is where the paw molds [Tye] made earlier come in handy, since nobody would want Lucifur wearing a PLA splint fresh out of boiling water. Finally, she added a bit of super glue to the heel of the splint in hopes that it will hold up better over time.

We certainly can’t recommend DIY solutions to medical problems and [Tye] made sure she stressed the importance of following the recommendations of your vet if you’re ever in her position. Either way, we hope Lucifur finds some momentary reprieve, and that she can eventually receive those $1600 braces she desperately needs.

3D Printed Speaker Uses DSP For Ultimate Performance

July 25, 2020 by Lewin Day 17 Comments

Speaker design used to be as much about woodwork as it was about advanced acoustic mathematics. In recent decades, technologies such as digital signal processing and 3D printing have changed the game significantly. Leaning heavily on these techniques, [ssashton] developed a design called Mr. Speaker.

The speaker contains a 3″ woofer for good bass response, and twin tweeters to deliver stereo audio. Using WinISD to help do the requisite calculations on porting and volume, [ssashton] designed a swooping 3D printed enclosure with a striking design. Sound comes into the unit through an off-the-shelf Bluetooth module, before being passed to an ADAU1401 digital signal processing unit. From there, it’s passed to a mono amp to drive the woofer and a stereo one for the tweeters.

To get the flattest frequency response possible and maintain linear phase, it’s all about DSP in this case. RePhase software was used to design a DSP filter to achieve these goals, helping the speaker to produce the desired output. The ADAU1401 DSP was then programmed using Sigma Studio, which also allows the designer to do things such as split outputs for seperate woofer and tweeter drives.

[ssashton] does a great job of explaining both DSP principles and old-school speaker design tricks, from phase plugs to reflections. The use of 3D printed parts to rapidly iterate the design is impressive, too. We’d love to see the final enclsoure get an acetone smoothing treatment to really take it over the edge.

If you’re into serious speaker design and want more, be sure to check out this advanced transmission line design. For those of you with your own builds with some nifty tricks, drop us a note on the tipline.

Simple Plasma Cutter Collision Detection System

July 25, 2020 by Lewin Day 7 Comments

Machine tools often have powerful drive motors, allowing them to work quickly and accurately to get the job done fast. However, this can cause major damage if the tool head collides with an unexpected object. To protect against such occurances, [Xnaron] developed a simple system to shut down his plasma cutter in the event of a crash.

The system consists of a 3D printed collar that fits around the plasma cutting torch. The collar has two mating parts, which are held together with three magnets and three ball bearings to act as a key, maintaining the correct orientation. Three limit switches are then fitted, held closed by the two mating halves. When the torch collides with an object, this causes the magnetic coupling to seperate, triggering one or more of the limit switches, and shutting down the machine safely.

Video of an unplanned collision shows the device working well. It’s a neat solution that could probably be adapted to other types of machine tool that don’t experience high lateral forces. Of course, if you don’t yet have a plasma cutter, you can always make your own. Video after the break.

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ESP8266 Makes A Wireless Card Reader

July 25, 2020 by Al Williams 19 Comments

You can find commercial USB sticks that can also connect via WiFi. But [Neutrino] made his own using an ESP8266 married to a card reader. It all starts with the old trick of soldering a header to an SD card adapter. The USB port is still there, but it is only for power. A 3.3 V regulator and an ESP12E board round out the hardware.

Of course, the trick is the software. Starting from a few examples, he wound up providing an FTP server that you can connect to and send or receive files using that protocol.

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Stop Bad Laws Before They Start

July 25, 2020 by Elliot Williams 88 Comments

With everything else going on this summer, you might be forgiven for not keeping abreast of new proposed regulatory frameworks, but if you’re interested in software-defined radio (SDR) or even reflashing your WiFi router, you should. Right now, there’s a proposal to essentially prevent you from flashing your own firmware/software to any product with a radio in it before the European Commission. This obviously matters to Europeans, but because manufacturers often build hardware to the strictest global requirements, it may impact everyone. What counts as radio equipment? Everything from WiFi routers to wearables, SDR dongles to shortwave radios.

The idea is to prevent rogue reconfigurable radios from talking over each other, and prevent consumers from bricking their routers and radios. Before SDR was the norm, and firmware was king, it was easy for regulators to test some hardware and make sure that it’s compliant, but now that anyone can re-flash firmware, how can they be sure that a radio is conformant? Prevent the user from running their own firmware, naturally. It’s pretty hard for Hackaday to get behind that approach.

The impact assessment sounds more like advertising copy for the proposed ruling than an honest assessment, but you should give it a read because it lets you know where the commission is coming from. Reassuring is that they mention open-source software development explicitly as a good to be preserved, but their “likely social impacts” include “increased security and safety” and they conclude that there are no negative environmental impacts. What do you do when the manufacturer no longer wants to support the device? I have plenty of gear that’s no longer supported by firmware updates that is both more secure and simply not in the landfill because of open-source firmware.

Similarly, “the increased capacity of the EU to autonomously secure its products is also likely to help the citizens to better protect their information-related rights” is from a bizarro world where you can trust Xiaomi’s home-automation firmware to not phone home, but can’t trust an open-source replacement.

Public comment is still open, and isn’t limited to European citizens. As mentioned above, it might affect you even if you’re not in the EU, so feel free to make your voice heard. You have until September, and you’ll be in some great company if you register your complaints. Indeed, reading through the public comments is quite heartening: Universities, researchers, and hackers alike have brought up reasons to steer clear of the proposed approach. We hope that the commission hears us.

Jet Airliner Nacelle Becomes A Unique Camper

July 25, 2020 by Jenny List 47 Comments

It’s possible that some of you will have thought about making a custom camper for yourselves. Some of you may even have gone as far as to build a teardrop caravan. It’s very unlikely though that you’ll have gone as far as [Steve Jones] though, who took an outer engine nacelle from a retired ex-RAF VC-10 airliner and converted it into a camper that is truly one of a kind.

On the face of it a jet engine nacelle should be an easy shell for such a project, but such a simplified view perhaps doesn’t account for the many vents, pipes, and hatches required by the engine in flight. Turning it into a waterproof housing for a camper was a significant job, which he has managed to do while leaving one set of engine access doors available as a large opening for a room with a view.

The nacelle is mounted on a narrowed former caravan chassis, and with an eye-catching window created from its former air intake and a very well executed interior fit-out it makes for a camper that many of us would relish trying for ourselves. You can see a video of it below the break, and we wish we could be lucky enough to encounter it in a campsite one summer.

We’ve shown you our share of campers over the years, but perhaps this 3D printed one has most appeal.

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