TechyMagThings

“Lights, camera, action!” might have been the call when recording back in the day, but for an awesome three-dimensional viewing experience, you might try yelling “Mist, Mirrors, Laser!” and following in the footsteps of [Ancient]’s latest adventure in voxel displays, which is also embedded below.

He starts with a naive demonstration: take a laser projector and toss an image into a flat cloud of mist. That demonstrates that yes, the mist does resolve an image, and that the viewing angle is very poor– that is, brightness drops off sharply when you’re out of line from the projector. In this case, that’s a good thing! It means more angles can be projected into that mist for a three-dimensional, hologram effect.

The optical train gets folded up, probably to make this fit on a tabletop: first, an array of flat mirrors in front of the projector splits the image from the projector into multiple viewpoints, which are each bounced to a second flat mirror that sends the image into the fog bank.

Some might call the resulting image a hologram; others might complain that that’s technically something totally different, and that this volumetric display is just all smoke and mirrors. We can hope that [Ancient] sees fit to share more details, like the software stack needed to generate the video feed– though it’s likely using a version of the same software as his last volumetric display, which used the same laser but whose point cloud was made from a bubblegram rather than an actual cloud. With a lot more points, though, the resolution is amazing in comparison, at the cost of appearing fuzzy at the edges. Unfortunately, we do not see the display in this demo run DOOM, as one of his previous projects did.

This video is more of a demo than a how-to, but it’s a heck of an impressive demo. If you don’t feel like watching the assembly, jump right to 9:00 to be impressed. It comes across a lot better on video than in the screenshot.

It’s been three weeks since the Artemis II crew returned to Earth, and while the mission might be over for Reid Wiseman, Victor Glover, Christina Hammock Koch, and Jeremy Hansen, the work is only just beginning for engineers back at NASA. In a blog post earlier this week, the space agency went over the preliminary post-mission assessments of the spacecraft and its ground support equipment, and detailed some of the work that’s currently taking place as preparations begin for Artemis III.

During Artemis I, higher than expected damage was noted on both the Orion’s heat shield and the Space Launch System (SLS) launch pad. But according to NASA, the changes implemented after that first mission seem to have prevented similar issues this time around. The post also explains that reusable components of the Orion spacecraft, such as the avionics and the crew seats, are already in the process of being removed from Integrity so they can be installed in the next capsule on the production line.

While watching the live stream of the Artemis mission is the closest most of us will ever get to experiencing spaceflight, that doesn’t mean you can’t explore the solar system from the comfort of your own home — or more specifically, your browser. [Sani Huttunen] has created an incredible web-based solar system simulator that lets you explore our celestial neighborhood throughout different periods of time. You can tour the moons of Jupiter, see how the planets aligned on the date of your birth, and even check in on the Voyager probes. There are some very valid reasons to be skeptical about software moving to the web, but we’ve got to admit, this is a very slick demonstration of just how far modern browsers have come.

Speaking of how far things have come, are you ready for a car without a rear window? Polestar certainly hopes so, as their latest model does away with such quaint concepts. The glass panel in the roof ends right around the back headrests, and while the rear of the vehicle does open up for storage, the hatch is completely solid. In place of the traditional mirror, there’s a “high resolution” 1480 x 320 display that shows the feed from a rear-mounted camera.

No, that’s not a typo. At a time when smartphones are shipping with 2K displays, should the driver want to see what’s going on behind their $70,000+ USD electric vehicle, they’re limited to seeing it at a vertical resolution below that of VGA. We’d make a joke about Polestar offering up a “Rearview+” upgrade down the line that would give the driver a higher resolution view, but honestly, it’s getting a little too close to reality to be funny.

If that last one has you wishing for a reminder of simpler times, how about some new software for using the iconic Wii Remote as an input device? The Wii and its revolutionary controllers may be turning 20 later this year, but that hasn’t stopped the dedicated fans. This new wrapper provides accelerometer calibration, infrared tracking, and the ability to remap the Wii Remote’s buttons and create key combos. If you do something cool with it, we’d love to hear about it.

Finally, on the other end of the input spectrum, some details leaked out this weekend about Valve’s upcoming Steam controller — namely, the fact that it will cost players $99 at release. As reported by VICE, a hands-on review of the controller by TechyTalk was accidentally published early on YouTube, providing the public with pricing info ahead of an official announcement.

At first blush, this might seem like a lot of money to pay for a game controller, but it’s actually within striking distance of the sticker price on the standard controllers on the Xbox and PlayStation consoles. Perhaps more critically, it’s around half the price of the official “premium” controller offerings available for the aforementioned systems. Is it really any wonder that we’ve got cars without rearview mirrors when folks are putting down 200 bucks for a fancy PlayStation controller?

See something interesting that you think would be a good fit for our weekly Links column? Drop us a line, we’d love to hear about it.

For those first venturing into sailing, it can be overwhelming since the experience is thick with jargon and skills that don’t often show up in life ashore. With endless choices, including monohulls versus catamarans, fiberglass versus wood, fractional versus masthead rigs, and sloops versus ketches, a new sailor risks doing something like single-handing a staysail schooner when they should have started on a Bermuda-rigged dinghy without a spinnaker. Luckily, there are some shortcuts to picking up the hobby, like the venerable Sunfish or Hobie ships. It’s also possible to build a simple sailing vessel completely out of materials from a local hardware store, as [Cumberland Rover] has been demonstrating.

[Cumberland Rover] has a number of homemade vessels under his belt, from various kayaks and rowboats. His latest project is a 12-foot rowboat, which has the option to add a mast and sail. The hull is made from two 1×12 pieces of lumber, bent around a frame and secured. Plywood makes the bottom, and a few seats finish out the build. He’s also using standard hardware to fasten everything together, which helps with maintenance. It came in handy when he recently added some height to the bow of the boat to improve seaworthiness.

For sailing, the mast is made out of two pieces of 2x lumber glued together and then worked into a more cylindrical shape. It’s unstayed, reducing complexity, and although he broke one in extremely high winds, it is more than strong enough for most of his sailing. The ship is gaff-rigged, with a square sail hoisted up the mast by a wooden spar. All of these design choices make it quick and easy to set the sail up when the wind is good or pack it away fast when it’s time to row.

Although there are paid plans available on his website, the methods used in the video show how simple it can be to get into rowing or sailing with a minimal cost. You’ll still want to learn the basics of sailing before taking one of these out into open water. DIY speedboats are also possible and accessible as well, but there’s the added complexity of a motor here to think about, as well as registration requirements that often accompany powered craft.

If you take a video of a spinning wheel, you’ll probably notice that the spokes appear to turn more slowly than the wheel is actually rotating, and sometimes in the wrong direction. This is caused by a near match in the frame rate of the camera and the rate of rotation of the wheel – each time the camera captures a frame, the wheel has rotated a spoke into nearly the same position as in the last frame. If you time the exposures carefully, as [Excessive Overkill] did in his latest video, this effect can seemingly freeze moving objects, such as a fan or saw blade.

Most cameras only allow relatively coarse, fixed adjustments to frame rate, making it difficult to synchronize the shutter to an object’s motion. To get around this, [Excessive Overkill] used an industrial camera (previously used in this aimbot), which has fine frame rate control and external triggering. He connected the external trigger to a laser sensor, which detects a piece of retroreflective tape every time it passes by (for example, on one blade of a fan). When the laser sensor sends a signal, it also triggers a powerful LED flash. The flash is so powerful that dark materials create a hum when exposed to it, as pulses quickly heat the material, but each pulse is also so brief that the flash board doesn’t require any cooling.

Even to the naked eye, these stroboscopic pulses make rotating objects seem to stand still – an effect which made [Excessive Overkill] extra cautious when working around a lathe. When using a suitably long exposure time to avoid rolling-shutter distortion, the effect worked even using a normal camera without frame-rate matching. [Excessive Overkill] took videos of debris flying away from a seemingly motionless bandsaw, milling machine, chop saw, and jigsaw, though it was harder to freeze the rotation of a weed trimmer and a drone.

We’ve seen this effect used to freeze motion a few times before, both for art and for entertainment. If you’d like to recreate it, check out this high-speed LED flash.

Thanks to [Keith Olson] for the tip!

If you follow [Maker’s Muse] on YouTube, you know he’s as passionate about robot fights these days as he is about the tools he uses to make the robots. Luckily for us, he’s still got fame as a 3D printing YouTuber, as this has given him the platform to share his trade secrets for strong, robot-combat-worthy prints.

He fights robots in a ‘plastic ant-weight’ division, which restricts not only the weight of the robot but also the materials used. Not only must they be primarily plastic, but only certain plastics are allowed: PLA is in, but engineering filaments, Nylon, and TPU are out. Since necessity is the mother of invention, this has led to strong evolutionary pressure to figure out how to print the most impact-resilient PLA parts for armor and spinners.

He’s using the latest OrcaSlicer and shares the profile as a pay-what-you-want 3MF file. It’s all about solidity: a solid part with solidly fused walls and solidly linked layers. It makes sense: if you’re going to be hammering on or with these parts, you don’t want any internal voids that could either collapse or pull open.

The infill density is obviously 100%, and you’ll want a concentric pattern — this makes it look like you’re just printing walls, but it allows you to use another trick. To make sure those walls don’t all align, creating a potential weakness, OrcaSlicer’s “alternate extra wall” will put one extra wall every second layer. The extra wall causes the infill pattern to stagger and lock together.

Also helping lock it together, he’s playing with extrusion widths, with the suggested rule-of-thumb being the line width on the walls be one-half that of the internal fill — and as wide as possible. In his case, with a 0.4 mm nozzle, that means 0.4 mm wide walls and 0.8 mm for the infill. OrcaSlicer 2.3.2 also lets you play with specific flow ratios, allowing you to overextrude only the internals for strength, without overextruding on the walls and potentially ruining dimensional accuracy. He also irons all top surfaces, but admits that that’s mostly about aesthetics. The iron may make those layers a little bit stronger, though, so why not?

Would brick layers make these parts even stronger? That’s very likely; [Maker’s Muse] mentions them in the video but does not use them because they’re not implemented in-slicer, and he wants something accessible to all. On the other hand, this post-processing script seems accessible enough for our crowd.

This video/profile is exclusively about fully-solid parts. When you want strong parts that aren’t fully solid, it looks like the answer is walls.

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A lot has been made about a post-quantum computer future in which traditional encryption methods have suddenly been rendered obsolete. With this terrifying idea in mind, it’s reassuring to see some recent pushback to the idea with some factual evidence. In a recent blog post by [Filippo Valsorda] – a cryptography engineer – the point is raised that 128-bit symmetric keys like AES-128 and SHA-256 are at risk of being obliterated in a post-quantum future.

Rather than just taking [Filippo]’s word for it, he takes us through a detailed explanation of the flawed understanding of Grover’s algorithm that underlies much of the panic. While it’s very true that this quantum search algorithm can decrease the amount of time required to find a solution, the speed-up with a single thread is quadratic, not exponential. While asymmetric cryptography systems like ECDH, RSA, and kin are very much at risk courtesy of Shor’s algorithm, the same is not true for symmetric systems.

An interesting detail with Grover’s is also that you cannot simply run a search in parallel to get a corresponding speed-up, as it’s not a parallel problem. Barring a breakthrough that replaces Grover’s with something that lends itself better to such a parallel search, it would seem that we won’t have to abandon classical encryption any time soon.

Incidentally, even for Shor’s algorithm, there are still some hold-ups. Current quantum computers are not even able to factor 21 yet. Meanwhile, supposed quantum computing breakthroughs are being trolled with a Commodore 64.

Although 3D printing it a great tool for making all sorts of things, the nature of the plastics used in most desktop FDM printers means it isn’t the first tool most would think of to build an internal combustion engine. [Alexander] is evidently not most people, as he’s on his third generation 3D printed engine.

There are 3D printed pumps to distribute coolant water and oil, plus some clever engineering in the head to make sure they don’t mix — a problem with a previous iteration. As you probably guessed, the engine isn’t fully printed. Assembling it requires add-on hardware for things like bearings, belts, and filters.

But it’s still impressive just how much of this beast is actually made of plastic. Not even fancy engineering plastic, either — there are a few CF-Nylon parts, but most of it is apparently good old ASA and ABS.

If you’re looking for “cheats”, the plastic engine block does get a stainless steel sleeve, and the head is CNC’d aluminum, but we hesitate to call anything that gets a homemade engine running a “cheat”. It’s hard enough using all the ‘right’ materials. Just like another 3D printed engine we featured, the carb is also an off-the-shelf component.

Still, it’s the dancing bear all over again: it’s not how well it runs that impresses, but the fact that it runs at all. We’ve also seen hackers use 3D printing to make steam engines, hot-air Stirling engines, and electric motors— all with varying amounts of non-printed parts.