Help Thrust Open Source Satellites To The Next Level

To place a satellite in orbit satisfactorily it is necessary not only to hitch a ride on a rocket, but also to put it in the right orbit for its task, and once it is there, to keep it there. With billions of dollars or roubles of investment over six decades of engineering behind them the national space agencies and commercial satellite builders solved these problems long since, but replicating those successes for open source microsatellites still represents a significant engineering challenge. One person working in this field is [Michael Bretti], who is doing sterling work with a shoestring budget on open source electric thrusters for the smallest of satellites, and he needs your help in crowdfunding a piece of equipment.

Beware suspiciously cheap eBay vacuum pumps!
Beware suspiciously cheap eBay vacuum pumps!

As part of his testing he has a vacuum chamber, and when he places a thruster inside it he has to create a space-grade vacuum . This is no easy task, and to achieve it he has two pumps. The first of these, a roughing pump, is a clapped-out example that has clearly reached the end of its days, and it is this that he needs your help to replace. His GoFundMe page has a modest target of only $4,200 which should be well within the capabilities of our community in reaching, and in supporting it you will help the much wider small satellite community produce craft that will keep giving us interesting things from space for years to come.

We’ve mentioned his work before here at Hackaday, and we hope that in time we’ll have a chance to look in more detail at his thrusters. Meanwhile you can follow along on Twitter.

Thanks [Bruce Perens K6BP] for the tip.

3D Printing Transmission Line Speakers

Anyone who has played with speakers on the workbench knows the huge difference enclosure design makes to the frequency response of an audio system. Speakerheads spend hours tinkering with designs and calculations, aiming to get the best out of a given set of drivers. [HexiBase] decided to try some experiments of his own, running into some hurdles along the way.

[Hexibase] aimed to 3D print a compact transmission line design, to suit a pair of 1 1/8″ full-range drivers. Being aware of the benefits of high-resolution resin 3D printing, he set out to print a design taking full advantage of the build volume of his Longer 3D Orange 30 printer. Unfortunately, after much fiddling with slicer settings, the printer turned out to have a fundamental fault, leading to unusable prints.

Undeterred, [Hexibase] switched to using his Longer FDM model instead. Printing out the enclosures in PLA. he noted that the different material will have a slightly altered frequency response than originally intended. Regardless, the final result sounds great, and barring some higher-frequency anomalies, the output correlates well with the mathematical model of expected performance.

3D printers make great tools for budding speaker builders, as they make constructing advanced geometries a cinch. Of course, you can even try and 3D print the drivers themselves if you’re so inclined. Video after the break.

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Hackaday Links: June 21, 2020

When Lego introduced its Mindstorms line in 1998, in a lot of ways it was like a gateway drug into the world of STEM, even though that term wouldn’t be invented for another couple of years. Children and the obsolete children who begat them drooled over the possibility of combining the Lego building system with motors, sensors, and a real computer that was far and away beyond anything that was available at the time. Mindstorms became hugely influential in the early maker scene and was slowly but steadily updated over the decades, culminating with the recently released Mindstorms Robot Inventor kit. In the thirteen years since the last release, a lot has changed in the market, and we Hackaday scribes had a discussion this week about the continued relevancy of Mindstorms in a time when cheap servos, microcontrollers, and a bewildering array of sensors can be had for pennies. We wonder what the readers think: is a kit that burns a $360 hole in your pocket still worth it? Sound off below.

Are you looking for a way to productively fill some spare time? Plenty of people are these days, and Hackaday has quite a deal for them: Hackaday U! This series of online courses will get you up to speed on a wide range of topics, starting tomorrow with Matthew Alt’s course on reverse engineering with Ghidra. Classes meet online once a week for four weeks, with virtual office hours to help you master the topic. Beside reverse engineering, you can learn about KiCad and FreeCad, quantum computing, real-time processing of audio and sensor data, and later in the year, basic circuit theory. We’ve got other courses lined up to fill out the year, but don’t wait — sign up now! Oh, and the best part? It’s on a pay-as-you-wish basis, with all proceeds going to charity. Get smarter, help others while doing it — what’s not to love about that?

Speaking of virtual learning, the GNU Radio Conference will be moving online for its 10th anniversary year. And while it’s good news that this and other cons have been able to retool and continue their mission of educating and growing this community, it’s still a bummer that there won’t be a chance to network and participate in all the fun events such cons offer. Or perhaps there will — it seems like the Wireless Capture the Flag (CTF) event is still going to happen. Billed as “an immersive plot-driven … competition featuring the GNU Radio framework and many other open-source tools, satellite communications, cryptography, and surreal global landscapes,” it certainly sounds like fun. We’d love to find out exactly how this CTF competition will work.

Everyone needs a way to unwind, and sometimes the best way to do that is to throw yourself into a project of such intricacy and delicate work that you’re forced into an almost meditative state by it. We’ve seen beautiful examples of that with the wonderful circuit sculptures of Mohit Bhoite and Jiří Praus, but here’s something that almost defies belief: a painstakingly detailed diorama of a vintage IBM data center. Created by the aptly named [minatua], each piece of this sculpture is a work of art in its own right and represents the “big iron” of the 1400 series of computers from the early 1960s. The level of detail is phenomenal — the green and white striped fanfold paper coming out of the 1403 line printer has tiny characters printed on it, and on the 729 tape drives, the reels spin and the lights flash. It’s incredible, all the more so because there don’t appear to be any 3D-printed parts — everything is scratch built from raw materials. Check it out.

As you can imagine, the Hackaday tip line attracts a fair number of ideas of the scientifically marginal variety. Although we’re not too fond of spammers, we try to be kind to everyone who bothers to send us a tip, but with a skeptical eye when terms like “free energy” come across. Still, we found this video touting to Nikola Tesla’s free energy secrets worth passing on. It’s just how we roll.

And finally, aside from being the first full day of summer, today is Father’s Day. We just want to say Happy Father’s Day to all the dads out there, both those that inspired and guided us as we were growing up, and those who are currently passing the torch to the next generation. It’s not easy to do sometimes, but tackling a project with a kid is immensely important work, and hats off to all the dads who make the time for it.


VGA Framegrabber Built From Scratch

Modern computers are replete with all manner of digital video interfaces. DVI, HDMI, DisplayPort are all examples of this. In the old days, VGA ruled the roost, sending video to monitors as an analog signal. However, it’s possible to convert this back into a digital format, and [vihapuu] has done just that with his Grabor project. (a demo video is also embedded below.)

The project relies on a Texas Instruments TVP7002 to do the hard work of converting VGA into a digital signal. The output of this chip is then picked up by a CPLD which clocks the resulting data into SRAM. An NXP microcontroller is then responsible for taking the data from SRAM and sending it out over a network interface, thanks to a Microchip ENC28J60 Ethernet controller.

We can imagine this kind of tool would come in handy for working with retro machines over a network. We’ve seen other interesting VGA hacks before too, like this EEPROM-based signal generator. Video after the break.

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Decapsulating A Dual Triode

We see quite a bit of work where people decapsulate ICs or other solid state devices to expose their inner workings. But how about hollow state? [Tomtektest] had a dual triode that has lost its vacuum integrity — gone to air, as he calls it — and decided to open it up to better expose its inner workings. (Video, embedded below.)

Of course, you can always see the innards through the glass, but it is interesting to have the envelope out of the way. Apparently, how you remove the glass is a bit tricky if you don’t want to damage the working bits as you remove it.

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Custom Portable N64 Embraces Modern Making

In the beginning, there was hot glue. Plus some tape, and a not inconsiderable amount of Bondo. In general, building custom portable game consoles a decade or so in the past was just a bit…messier than it is today. But with all the incredible tools and techniques the individual hardware hacker now has at their disposal, modern examples are pushing the boundaries of DIY.

This Zelda: Ocarina of Time themed portable N64 by [Chris Downing] is a perfect example. While the device is using a legitimate N64 motherboard, nearly every other component has been designed and manufactured specifically for this application. The case has been FDM 3D printed on a Prusa i3, the highly-detailed buttons were printed in resin on a Form 3, and several support PCBs and interface components made the leap from digital designs to physical objects thanks to the services of OSH Park.

A custom made FFC to relocate the cartridge port.

Today, those details are becoming increasingly commonplace in the projects we see. But that’s sort of the point. In the video after the break, [Chris] breaks down the evolution of his portable consoles from hacked and glued together monstrosities (we mean that in the nicest way possible) to the sleek and professional examples like his latest N64 commission. But this isn’t a story of one maker’s personal journey through the ranks, it’s about the sort of techniques that have become available to the individual over the last decade.

Case in point, custom flexible flat cables (FFC). As [Chris] explains, when you wanted to relocate the cartridge slot on a portable console in the past, it usually involved tedious point-to-point wiring. Now, with the low-volume production capabilities offered by companies like OSH Park, you can have your own flexible cables made that are neater, faster to install, and far more reliable.

Projects like this one, along with other incredible creations from leaders in the community such as [GMan] are changing our perceptions of what a dedicated individual is capable of. There’s no way to be sure what the state-of-the-art will look like in another 5 or 10 years, but we’re certainly excited to find out.

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Score Big Against Boredom With Tabletop Bowling

Bowling has been around since ancient Egypt and continues to entertain people of all ages, especially once they roll out the fog machine and hit the blacklights. But why pay all that money to don used shoes and drink watered-down beer? Just build a tabletop bowling alley in your spare time and you can bowl barefoot if you want.

Those glowing pins aren’t just for looks — the LEDs underneath them are part of the scoring system. Whenever a pin is knocked out of its countersunk hole, the LED underneath is exposed and shines its light on a corresponding light-dependent resistor positioned overhead. An Arduino Uno keeps track of of the frame, ball number, and score, and displays it on an LCD.

The lane is nearly six feet long, so this is more like medium-format bowling or maybe even skee-bowling. There are probably a number of things one could use for balls, but [lainealison] is using large ball bearings. Roll past the break to see it in action, but don’t go over the line!

Can’t keep your balls out of the gutter? Build a magic ball and make all wishful leaning more meaningful as you steer it down the lane with your body.

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