Theory, Practice, And Ducted Fans

May 10, 2022 by Elliot Williams 9 Comments

About a year ago, [Wyman’s Workshop] needed a fan. But not just a regular-old fan, no sir. A ducted fan. You know, those fancy fan designs where the stationary shroud is so close to the moving fan blades that there’s essentially no gap, and a huge gain in aerodynamic efficiency? At least in theory?

Well, in practice, you can watch how it turned out in this video. (Also embedded below.) If you’re more of a “how-to-build-it” type, you’ll want to check out his build video — there’s lots of gluing 3D prints and woodworking. But we’re just in it for the ducted fan data!

And that’s why we’re writing it up! [Wyman] made a nice thrust-testing rig that the fan can pull on to figure out how much force it put out. And the theory aimed at 652 g of thrust, which was roughly confirmed. And then you get to power: with a 500 watt motor, he ended up producing 47 watts. Spoiler: he’s overloading the motor, even though he used a fairly beefy bench grinder motor.

So he re-did the fan design, from scratch, to better match the motor. And it performed better than the theory said it would. A pleasant surprise, but it meant re-doing the theory, including the full volume of the fan blade, which finally brought theory and practice together. Which then lead him design a whole slew of fan blades and test them out against each other.

He ends the video with a teaser that he’ll show us the results from various inlet profiles and fan cones and such. But the video is a year old, so we’re not holding our breath. Still, if you’re at all interested in fan design, and aren’t afraid of high-school physics, it’s worth your time.

Don’t care about the advantages of ducted fans, but simply want to make your quad look totally awesome? Have we got the hack for you!

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Becky Stern, David Cranor, And A CT Scanner Vs The Oura Ring

May 10, 2022 by Elliot Williams 7 Comments

If you wonder how it’s possible to fit a fitness tracker into a ring, well, you’re not alone. [Becky Stern] sent one off to get CT scanned, went at it with a rotary tool, and then she made a video about it with [David Cranor]. (Video embedded below.)

While it’s super cool that you can do a teardown without tearing anything down these days — thanks to the CT scan — most of the analysis is done on a cut-up version of the thing through a normal stereo microscope. Still, the ability to then flip over to a 3D CT scan of the thing is nice.

We absolutely concur with [Becky] and [David] that it’s astounding how much was fit into very little space. Somewhere along the way, [David] muses that the electrical, mechanical, and software design teams must have all worked tightly together on this project to pull it off, and it shows. All along, there’s a nice running dialog on how you know what you’re looking at when tearing at a new device, and it’s nice to look over their shoulders.

Then there’s the bit where [Becky] shows you what a lithium-ion battery pack looks like when you cut it in half. She says it was already mostly discharged, and she didn’t burst into flames. But take it easy out there! (Also, make sure you take your hot xylene out on the patio.)

X-ray machines are of course just the coolest thing when doing a teardown. We’ve seen them used from fixing multimeters to simply looking at servo motors.

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Will MiSTer Fool You Into Learning FPGAs?

May 9, 2022 by Elliot Williams 45 Comments

What’s the killer app for FPGAs? For some people, the allure is the ultra-high data throughput for parallelizable tasks, which can enable some pretty gnarly projects. But what if you’re just starting out? How about 1980s style video games?

The MiSTer FPGA project created a bit of FPGA hardware that makes it easy to build essentially any old school video game or computer platform. That’s a massive clean slate. Of course, you can simply download someone else’s Atari ST or Commodore 64 setup and load it up, but if you want to learn FPGAs while recreating old-school video game machines, you’re going to want to get your hands dirty.

[Mister Retro Wolf] started up a video series last winter (trailer embedded below) where he’s embarked on a project to recreate a classic video game machine from the ground up using the MiSTer FPGA platform. In particular, he’s going to recreate the Namco Tank Battalion arcade game, from the schematics, in Verilog.

This is literally building a 6502-based video game machine from scratch (in gateware), so if you’re interested in retrocomputing or FPGAs, you’ll have something to learn here. He’s gotten through the CPU, screen, tilemap graphics, and memory so far, but it’s not done yet. To follow along, get yourself some hardware and you can probably catch up.

We’ve covered the MiSTer FPGA project before, of course, because we think it’s cool. And if a video game arcade machine is going to be your gateway drug into the seedy world of programmable gates, then so be it.

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Learning Obsolete Technology

May 7, 2022 by Elliot Williams 33 Comments

Tom Nardi and I were talking about his trip to the Vintage Computer Festival on the podcast, and he admitted to not having been a retrocomputer aficionado before his first trip. But he ended up keying some binary machine code into some collection of archaic silicon, and he got it. In the same episode, the sound of the week was a Strowger switch — the old electromechanical “brain” of telephone switching centers of old. The sample I used was from Sam of Look Mum No Computer on YouTube, who got one for his museum and thinks it’s just awesome.

Why do people like this kind of old (obsolete?) tech? It’s certainly not because it’s overwhelmingly capable — the giant old switch is replaced easily by a stack of silicon, and don’t even get me started on the old blinkenlights computer that Tom was keying on. In both of these cases, the people are significantly younger than the tech they’re playing around with, so that rules out nostalgia. What’s left?

I think it’s that sometimes the older technology is more immediate, more understandable, more tangible, and that resonates with people. In a time when we all have wonder devices that can do anything, programmed in languages that are pleasant, using libraries that are nothing short of magical in terms of making difficult things easy, understanding how things work down to the ground is a rare commodity.

But it’s a strange position to find ourselves in, technologically, where there’s almost necessarily a trade-off between the usefulness and functionality of a device with the ability to understand fundamentally how it works.

2022 Hackaday Prize Enters Second Round: Reuse, Recycle, Revamp

May 5, 2022 by Elliot Williams 8 Comments

Ding! That’s the bell for the second challenge round of the 2022 Hackaday Prize. If your project reuses or recycles what would otherwise be waste materials, or helps you to do the same for further projects, we want to see it.

Hackers are often frugal folk — we’ll recycle parts for projects because it’s easier on the pocketbook when prototyping. But in these strangest of times, when we’ve seen $1 microcontrollers in such shortage that they fetch $57 apiece (if you can get the parts at all), making use of what you’ve got on hand can be an outright necessity. If this is going to become the new normal, it’s going to make sense that we automate it. There’s gold, literally and metaphorically, in busted PCBs. How are you going to get the most value out of our broken electronic waste in our post-apocalyptic near future? Have you built an unpick-and-unplace machine? We’d like to see it.

But electronic parts are a small fraction of your recyclable materials, and plastics might play a larger role. If you’re a 3D printerer, you’ve doubtless thought about recycling plastic bottles into filament. Or maybe you’d like to take some of the existing plastics that are thrust upon you by this modern world and give them a second life? This factory churning out paving stones by remelting plastic with sand is doing it on an industrial scale, but could this be useful for the home gamer? Precious Plastic has a number of inspirational ideas. Or maybe you just need an HDPE hammer?

Have you built a fancy can crusher, or a plastics sorter, or a recycling robot? Head on over to Hackaday.io, write it up, and enter it into the Prize!

Basically any project that helps you recycle or reuse the material around you is fair game here. (But note that if you’ve got epic repair hacks, you’ll want to enter them in the upcoming Round Three: Hack it Back.) This round runs until June 12th and there are ten $500 awards up for grabs, so get hacking!

New Tech And The Old Ways

April 30, 2022 by Elliot Williams 8 Comments

This week on Hackaday, we featured a project that tickled my nostalgia bone, and proved that there are cool opportunities when bringing new tech to old problems. Let me explain.

[Muth] shared a project with us that combines old-school analog photography printing with modern LCD screens. The basic idea is to use a 4K monochrome screen in place of a negative, making a contact print by placing the screen directly on top of photographic paper and exposing it under a uniform light source. Just like the old ways, but with an LCD instead of film.

But what’s the main difference between a screen and film? You can change the image on the LCD at will, of course. So when [Muth] was calibrating out exposures, it dawned on him that he could create a dynamic, animated version of his image and progressively expose different portions of the paper, extending the available dynamic range and providing him the ability to control the slightest nuances of the resulting image contrast.

As an old photo geek, this is the sort of trick that we would pull off manually in the darkroom all the time. “Dodging” would lighten up a section of the image by covering up the projected light with your hand or a special tool for a part of the exposure time. With [Muth]’s procedure, he can dodge the image programmatically on the per-pixel level. We would have killed for this ability back in the day.

The larger story here is that by trying something out of the box, applying a new tool to an old procedure, [Muth] stumbled on new capabilities. As hackers, we’re playing around with the newest tech we can get our hands on all the time. When you are, it might be that you also stumble on new possibilities simply afforded by new tech. Keep your eyes open!

2022 Sci-Fi Contest: The Winners Are In

April 28, 2022 by Elliot Williams 4 Comments

The Sci-Fi Contest closed out on Monday, and we put our heads together and picked our favorites. And it was no easy task, because in addition to many of the projects simply looking stellar, many went all-out on the documentation as well, making these stellar examples that we can all learn from, whether you’re into sci-fi or not. But who are we kidding? From the responses we got, you are.

The Winners

[RubenFixit]’s Star Trek Shuttle Console is a Trek themed escape room in a box. The project’s extraordinary attention to detail and exhaustive project logs absolutely won our judges heart. From the LCARS graphics to the 3D printed isolinear chip bays and mimetic crystals, it’s all there. [Ruben] estimates about 300 hours of work went into this one, and it shows.

We had no shortage of robotic projects in the contest, but [RudyAramayo]’s R.O.B. won our judges over. This one is not a joke, weighing in at over 140 lbs of custom metalwork and righteous treads. It’s also made out of some expensive hardware all around, so maybe this isn’t your weekend-build robot. We love the comment on the Arduino test code suite: “For gods sake man, you must test your code when it becomes an autonomous vehicle.”

Finally, [zapwizard]’s Functional Razor Crest Control Lever is a prop and a video game controller in one. We can totally see Grogu playing with this, and we were wowed by the attention to detail in the physical build — with custom gears and a speed limiter — as well as the attention to prop-making detail. Some parts are custom-cut stainless steel plates. 3D printed parts are covered in aluminum tape and chemically aged. Awesome. Oh yeah, it’s also a working USB joystick.

These three winners will be receiving a $150 shopping spree at Digi-Key.