EMF Forming Was A Neat Aerospace Breakthrough

Typically, when we think about forming metal parts, we think about beating them with hammers, or squeezing them with big hydraulic presses. But what if magnets could do the squeezing? As it turns out—Grumman Aerospace discovered they can, several decades ago! Even better, they summed up this technique in a great educational video which we’ve placed below the break.

The video concerns the development of the Grumman EMF Torque Tube. The parts are essentially tubes with gear-like fittings mounted in either end, which are fixed with electromagnetic forming techniques instead of riveting or crimping. Right away, we’re told the key benefits—torque tubes built this way are “stronger, lighter, and more fatigue resistant” than those built with conventional techniques. Grumman used these torque tubes in such famous aircraft as the F-14 Tomcat, highlighting their performance and reliability.

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Inside A Mystery Aerospace Computer With [Ken Shirriff]

When life hands you a mysterious bit of vintage avionics, your best bet to identifying it might just be to get it in front of the biggest bunch of hardware hounds on the planet. After doing a teardown and some of your own investigation first, of course.

The literal black box in question came into [Ken Shirriff]’s custody courtesy of [David] from Usagi Electric, better known for his vacuum tube computer builds and his loving restoration of a Centurion minicomputer. The unit bears little in the way of identifying markings, but [Ken] was able to glean a little by inspecting the exterior. The keypad is a big giveaway; its chunky buttons seem optimized for use with the gloved hands of a pressure suit, and the ordinal compass points hint at a navigational function. The layout of the keypad is similar to the Apollo DSKY, which might make it a NASA artifact. Possibly contradicting all of that is the oddball but very cool electromechanical display, which uses reels of digits and a stepper-like motor to drive them.

Inside, more mysteries — and more clues — await. Unlike a recent flight computer [Ken] looked at, most of the guts are strictly electronic. The instrument is absolutely stuffed with PCBs, most of which are four-layer boards. Date codes on the hundreds of chips all seem to be in the 1967 range, dating the unit to the late 60s or early 70s. The weirdest bit is the core memory buried deep inside the stacks of logic and analog boards. [Ken] found 20 planes with the core, hinting at a 20-bit processor.

In the end, [Ken] was unable to come to any firm conclusion as to what this thing is, who made it, or what its purpose was. We doubt that his analysis will end there, though, and we look forward to the reverse engineering effort on this piece of retro magic.

Desktop Wind Tunnel Brings Aerospace Engineering To The Home Gamer

Computer simulation is indispensable in validating design and used in every aspect of engineering from finite element analysis to traffic simulation to fluid dynamics. Simulations do an amazing job and at a fraction of the time and expense of building and testing a scale model. But those visceral ah-ha moments, and some real-world gremlins, can be easier to uncover by the real thing. Now you don’t need a university research or megacorp lab to run aerodynamic study IRL, you can just build a functional desktop wind tunnel for a pittance.

[Mark Waller] shows off this tidy little design that takes up only about two feet of desk space, and includes the core features that make a wind tunnel useful. Air is pulled through the tunnel using a fan mounted at the exhaust side of the tunnel. The intake is the horn-like scoop, and he’s stacked up a matrix of drinking straws there to help ensure laminar flow of the air as it enters the tunnel. (The straw trick is frequently used with laminar flow water fountains). It also passes through a matrix of tubes about the diameter of a finger at the exhaust to prevent the spin of the fan from introducing a vortex into the flow.

For analysis, five tubes pipe in smoke from an vape pen, driven into the chamber by an aquarium pump. There’s a strip of LEDs along the roof of the tunnel, with a baffle to prevent the light shining on the black rear wall of the chamber for the best possible contrast. The slow-motion video after the break shows the effectiveness of the setup.

Whether you’re a Hackaday Editor cutting their own glider wing profiles using foam and hot wire, or just want to wrap your head around how different profiles perform, this will get you there. And it’ll do it at a fraction of the size that we’ve seen in previous wind tunnel builds.

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20 MPH IKEA Poäng Chair With Aerospace-Inspired Control Panel

Spending time at work sitting on the same drab chair can get boring after a while, even if you’re lucky to use a comfortable recliner. If you want to win the Office Olympics, you need something with a bit of pep. [StuffAndyMakes] wanted to build a completely ridiculous motorized office chair. A couple of years in the making, and he’s ready to unleash the 20 MPH IKEA Poäng chair with aerospace-inspired control panel!

The OfficeChairiot MkII, as he has christened it aptly,  is a motorized IKEA Poäng comfy chair. It uses off-the-shelf scooter parts to roll around : Batteries, motors, chains, sprockets, tires, axles, and  bearings. The OfficeChairiot MkII is basically three main parts – the Chassis, the Control Panel and the comfy chair. One of the main parts of the chassis is the motor controller  – The Dimension Engineering Sabertooth 2×60 motor controller – which is also used in beefy battlebots. It’s capable of carrying 1,000 lbs. of cargo and can feed the drive system up to 60 amps per motor channel .

The brain on the chassis is an Arduino Mega which can be controlled via a hand held remote. The Mega also receives data from various sensors for motor temperature, power wire temperature, ambient air temperature, wheel RPM’s, Accelerometer’s, seat occupancy and GPS data. The firmware is designed to ensure safety. The hand held remote needs to ping the on-board Arduino twice a second. If it doesn’t hear from the Remote for whatever reason, the unit stops and turns off the lights.

The Control Panel is one crazy collection of switches, buttons, displays, a missile switch, a master key switch – in all over 30 switches and buttons. All of the devices on the panel are controlled via a second Arduino Mega, helped by a custom multiplexer board to help connect the large number of devices.

Here are a few more features the OfficeChairiot MkII boasts of :

  • 1.5 Horsepower from two 500W scooter motors
  • 20W stereo and MP3 sound effects
  • Weapons sounds, 15 different fart sounds, car alarm, horns, etc.
  • All LED lighting: Headlights, turn signals, 88 undercarriage RGB LEDs
  • Plenty of homemade PCB’s
  • Custom built aluminum body panels (with help from Local Motors, the people behind the 3D printed car)

Aside from the handcrafted wood chassis and circuits boards and firmware, it’s all off-the-shelf stuff. [StuffAndyMakes] plans on open-sourcing the schematics, C++ code and CAD drawings – so post some comments below to motivate him to do so soon. We’d sure like to see a few more of these being built, so that Office Chair racing becomes a competitive sport. Check out the video after the break.

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I Gotta Print More Cowbell

Since the earliest days of affordable, home 3D printers, the technology behind them has been continuously improving. From lowering costs, improving print quality, increasing size and detail, and diversifying the types of materials, it’s possible to get just about anything from a 3D printer today with a minimum of cost. Some of the things that printers can do now might even be surprising, like this upgrade that makes [Startup Chuck]’s 3D printer capable of printing realistic-sounding cowbells out of plastic.

The key to these metal-like prints is a filament called PPS-CF which is a carbon fiber-reinforced polyphenylene sulfide, or PPS. PPS-CF has a number of advantages over other plastics including high temperature tolerance and high dimensional stability, meaning its less likely to warp or deform even in harsh environments. But like anything with amazing upsides, there are some caveats to using this material. Not only does the carbon fiber require more durable extruder nozzles but PPS-CF also needs an extremely hot print head to extrude properly in addition to needing a heated bed. In [Startup Chuck]’s specific case he modified his print head to handle temperatures of 500°C and his print bed to around 100°C. This took a good bit of work just to supply it with enough energy to get to these temperatures and caused some other problems as well, like the magnet on the printer bed demagnetizing above around 75°C.

To get to a working cowbell took more than just printer upgrades, though. He had to go through a number of calibrations and test prints to dial in not only the ideal temperature settings of the printer but the best thicknesses for the cowbell itself so it would have that distinct metallic ring. But cowbells aren’t the only reason someone might want to print with carbon-reinforced materials. They have plenty of uses for automotive, chemical processing, high voltage, and aerospace applications and are attainable for home 3D printers. Just make sure to take some basic safety precautions first.

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Hackaday Podcast Episode 323: Impossible CRT Surgery, Fuel Cells, Stream Gages, And A Love Letter To Microcontrollers

Elliot and Dan teamed up this week for the podcast, and after double-checking, nay, triple-checking that we were recording, got to the business of reviewing the week’s hacks. We kicked things off with a look at the news, including a potentially exciting Right to Repair law in Washington state and the sad demise of NASA’s ISS sighting website.

Our choice of hacks included a fond look at embedded systems and the classic fashion sense of Cornell’s Bruce Land, risky open CRT surgery, a very strange but very cool way to make music, and the ultimate backyard astronomer’s observatory. We talked about Stamp collecting for SMD prototyping, crushing aluminum with a boatload of current, a PC that heats your seat, and bringing HDMI to the Commodore 64.

We also took a look at flight tracking IRL, a Flipper-based POV, the ultimate internet toaster, and printing SVGs for fun and profit. Finally, we wrapped things up with a look at the tech behind real-time river flow tracking and a peek inside the surprisingly energetic world of fuel cells.

 

Download this entirely innocent-looking MP3.

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Open Source Hiding In Plain Sight

On the podcast, [Tom] and I were talking about the continuing saga of the libogc debacle. [Tom] has been interviewing some of the principals involved, so he’s got some first-hand perspective on it all – you should really go read his pieces. But the short version is that an old library that many Nintendo game emulators use appears to have cribbed code from both and open-source real-time operating system called RTEMS, and the Linux kernel itself.

You probably know Linux, but RTEMS is a high-reliability RTOS for aerospace. People in the field tell me that it’s well-known in those circles, but it doesn’t have a high profile in the hacker world. Still, satellites run RTEMS, so it’s probably also a good place to draw inspiration from, or simply use the library as-is. Since it’s BSD-licensed, you can also borrow entire functions wholesale if you attribute them properly.

In the end, an RTOS is an RTOS. It doesn’t matter if it’s developed for blinking LEDs or for guiding ICBMs. This thought got [Tom] and I to thinking about what other high-reliability open-source code is out there, hidden away in obscurity because of the industry that it was developed for. NASA’s core flight system came instantly to mind, but NASA makes much of its code available for you to use if you’re interested. There are surely worse places to draw inspiration!

What other off-the-beaten-path software sources do you know of that might be useful for our crowd?