Don’t Let Your PLA Filament Hang Loose With This 3D-Printed Surfboard

April 13, 2020 by 8 Comments

People always tend to push the boundaries of what is doable with a 3D printer.  This is also true for [AndrewW1977] when he decided to 3D print a full-sized functional surfboard.

With just over nine full days of printing time, 95 individual pieces, and using 3.1 kg of PLA (not counting all the test prints), this is certainly a monumental project. One of the bigger issues [AndrewW1977] had to solve was avoiding air pockets inside the board. Ideally, you would want to end up with only one continuous hollow chamber in order to easily vent all the air inside the board when it heats up. [AndrewW1977] chose to overcome this problem by using zero infill for each individual piece. The pieces were then connected with the help of alignment pins that have a central hole thereby connecting all hollow chambers.

By using a triangular shape, he managed to print all pieces without using supports. After gluing them together the whole board was covered with fiberglass and epoxy resin similar to traditional surfboard building. Unfortunately, due to the current situation with Covid19 [AndrewW1977] remains short of showing us the board in action. In case you have a 3D printer at home and lots of spare time during lockdown, [AndrewW1977] has published all files for his surfboard on Thingiverse.

As [AndrewW1977] points out in the video embedded below other people have already done similar projects. From jet boats to electric hydrofoils it seems that water sports and 3D printing are a perfect match.

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Will 2020 (Finally) Be The Year Of Electronic Paper?

April 13, 2020 by 85 Comments

These days paper is being phased out whenever possible, and while we’re still far from being a completely digital society, the last decade or two has seen a huge reduction in the amount of paper the average person deals with on a daily basis. At the very least, we seem a lot closer to a future without the printed page than we are flying cars or any of the other concepts we generally associate with the far-flung future.

That said, there’s still something undeniably appealing about reading on paper. The idea of squirting ink on a piece of thin wood might seem increasingly archaic to us, but it sure does look nice when you hold it in your hand. Which is exactly why so much effort has been put into recreating the look of printed paper in electronic form; we all love the experience of paper, but the traditional execution doesn’t align itself particularly well with modern sensibilities.

Of course electronic “eReaders”, most notably the Kindle line from Amazon, have gone a long way towards making this a reality. At least for reading books, anyway. But what about magazines, newspapers, or even the lowly notebook we keep by the bench to jot down measurements or ideas? A PDF datasheet, with graphics where the grey tones matter? Being able to carry a whole bookshelf worth of novels in your bag is incredible, but despite what science fiction has promised us since 2001: A Space Odyssey, we’re still consuming plenty of media off of dead trees.

But that might be changing soon. This year will see the release of two tablets that promise to deliver an experience much closer to reading and writing on traditional paper than anything we’ve seen previously. They certainly aren’t cheap, and it’s too early to tell how much is just hype, but these devices could end up being an important step towards the paperless future we’ve been dreaming of.

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Hams Cross The Atlantic On UHF

April 13, 2020 by 6 Comments

We often think of ham radio operators talking to exotic faraway lands, and that’s true for hams using the HF bands (below 30 MHz), especially if they have nice antennas. Modern living has made it much harder to have those big antenna farms, and today’s ham is more likely talking on VHF or UHF frequencies with very limited range under normal circumstances. Sure, you can use a repeater or bounce your signal from a satellite or the moon, but normal direct communication is normally going to be less than a typical commercial FM radio station. But on April 7th, two hams communicated across the Atlantic on 432 MHz — a UHF frequency. The distance was almost 4,000 km.

Notice we didn’t say they talked, but they communicated. The contact was via a somewhat controversial mode called FT8 which uses weak signal techniques to allow two computers to send limited amounts of information to each other. However, on April 10, the two stations reported a single sideband voice contact after they noticed the band conditions improving on the FT8 signal.

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Three Years Of HardwareX: Where Are They Now?

April 13, 2020 by 8 Comments

After three years of online publications, HardwareX may have solidified itself as an academic journal for open-source hardware. We originally wrote about HardwareX back in 2016. At the time, HardwareX hadn’t even published its first issue and only begun soliciting manuscripts. Now after three years of publishing, six issues as of October 2019 (with the seventh scheduled for April 2020), and an impact factor of 4.33, it’s fair to say that Elsevier’s push into open-access publications is on a path to success.

To give you a bit of background, HardwareX aims to promote the reproducibility of scientific work by giving researchers an avenue to publish all the hardware and software hacks that often get buried in traditional manuscripts. The format of HardwareX articles is a bit different than most academic journals. HardwareX articles look more like project pages similar to Hackaday.io. (Maybe we inspired them a bit? Who knows.)

It’s a bold attempt on Elsevier’s part because although open-access is held as an ideal scenario for scientific work, such efforts often come under quite a bit of scrutiny in the academic community. Don’t ask us. We can’t relate.

Either way, we genuinely wish Elsevier all the best and will keep our eyes on HardwareX. Maybe some of our readers should consider publishing their projects in HardwareX.

Touch Face, Lights Chase, Sirens Race

April 13, 2020 by 4 Comments

Let’s face it — people are gonna touch their faces. Sometimes faces itch, especially during allergy season. But the first step toward quitting something like that is to become cognizant of just how often you do it.

With a bracelet like this one from [Mauricio Martins], your face-touching frequency will quickly become apparent. Strap it to your favorite face-scratching arm and go about your day. The code constantly polls the accelerometer to see if your hand is in the vicinity of your visage. If so, red lights circle around and an emergency vehicle-type siren goes off to let everyone around you know you’ve sinned.

This no-touch-face bracelet is awesome because it’s simple and it works. It uses a Circuit Playground Express programmed in Make code, but it would be easy to port it to Arduino or CircuitPython. If you want to make something more elegant, we’re all for it, but you could be using this in the meantime to help condition yourself away from the habit. Check out the demo after the break.

Sometimes you gotta take a step back and make something that just works without getting all fancy. Did you hear the one about the astrophysicist who got magnets stuck up his nose trying to solve this very problem?

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Homebrew Loop Antenna Brings The Shortwave World To You

April 12, 2020 by 36 Comments

Radio may be dead in terms of delivering entertainment, but it’s times like these when the original social network comes into its own. Being able to tune in stations from across the planet to get fresh perspectives on a global event can even be a life saver. You’ll need a good antenna to do that, which is where this homebrew loop antenna for the shortwave radio bands shines.

To be honest, pretty much any chunk of wire will do as an antenna for most shortwave receivers. But not everyone lives somewhere where it’s possible to string up a hundred meters of wire and get a good ground connection, which could make a passive loop antenna like this a good choice. Plus, loops tend to cancel the electrical noise that’s so part of life today, which can make it easier to pull in weak, distant stations.

[Thomas]’s design is based on a length of coaxial cable, which should be stiff enough to give the loop some stability, like a low-loss RG-8 or RG-213. The coax braid and dielectric are exposed at the midpoint of the cable to create a feed point, while the shield and center conductor at the other ends are cross-connected. A 1:1 transformer is wound on a toroid core to connect to the feedpoint; [Thomas] calls it a balun but we tend to think it’s more of an unun, since both the antenna and feedline are unbalanced. He reports good results from the loop across the shortwave band.

The shortwave and ham bands are a treasure trove of information and entertainment just waiting to be explored. Check them out — you might learn something, and you might even stumble across spies doing their thing.

[via RTL-SDR.com]

Stitching Up Custom Belts

April 12, 2020 by 17 Comments

If you’ve got a 3D printer, you’re probably familiar with the reinforced belts that are commonly used on the X and Y axis. These belts either come as long lengths that you attach to the machine on either end, or as a pre-sized loop. Traditional wisdom says you can’t just take a long length of belt and make your own custom loops out of it, but [Marcel Varallo] had his doubts about that.

This is a simple tip, but one that could get you out of a bind one day. Through experimentation, [Marcel] has found that you can use a length of so-called GT2 belt and make your own bespoke loop. The trick is, you need to attach the ends with something very strong that won’t hinder the normal operation of the belt. Anything hard or inflexible is right out the window, since the belt would bind up as soon as it had to go around a pulley.

It seems the key is to cut both ends of the belt very flat, making sure the belt pattern matches perfectly. Once they’ve been trimmed and aligned properly, you stitch them together with nylon thread. You want the stitches to be as tight as possible, and the more you do, the stronger the end result will be.

[Marcel] likes to follow this up with a bit of hot glue, being careful to make sure the hardened glue takes the shape of the belt’s teeth. The back side won’t be as important, but a thin layer is still best. The end result is a belt strong enough for most applications in just a few minutes.

Would we build a 3D printer using hand-stitched GT2 belts? Probably not. But during a global pandemic, when shipments of non-essential components are often being delayed, we could certainly see ourselves running some stitched together belts while we wait for the proper replacement to come in. Gotta keep those face shields printing.