Microsoft Discontinues Kinect, Again

August 26, 2023 by Donald Papp 17 Comments

The Kinect is a depth-sensing camera peripheral originally designed as a accessory for the Xbox gaming console, and it quickly found its way into hobbyist and research projects. After a second version, Microsoft abandoned the idea of using it as a motion sensor for gaming and it was discontinued. The technology did however end up evolving as a sensor into what eventually became the Azure Kinect DK (spelling out ‘developer kit’ presumably made the name too long.) Sadly, it also has now been discontinued.

The original Kinect was a pretty neat piece of hardware for the price, and a few years ago we noted that the newest version was considerably smaller and more capable. It had a depth sensor with selectable field of view for different applications, a high-resolution RGB video camera that integrated with the depth stream, integrated IMU and microphone array, and it worked to leverage machine learning for better processing and easy integration with Azure. It even provided a simple way to sync multiple units together for unified processing of a scene.

In many ways the Kinect gave us all a glimpse of the future because at the time, a depth-sensing camera with a synchronized video stream was just not a normal thing to get one’s hands on. It was also one of the first consumer hardware items to contain a microphone array, which allowed it to better record voices, localize them, and isolate them from other noise sources in a room. It led to many, many projects and we hope there are still more to come, because Microsoft might not be making them anymore, but they are licensing out the technology to companies who want to build similar devices.

Supremely-tough Glass Performs Under Pressure

August 24, 2023 by Donald Papp 25 Comments

There’s some nifty research from the University of Bayreuth, together with partners in China and the U.S., on creating supremely tough aluminosilicate glass that boasts an unusual structure. The image above represents regular glass structure on the left, and the paracrystalline structure on the right.

Aluminosilicate, which contains silicon, aluminum, boron and oxygen, is a type of oxide glass. Oxide glasses are a group to which borosilicate and other common glasses belong. Structurally speaking, these glasses all have a relatively disordered internal structure. They’re known for their clarity, but not especially their durability. Continue reading “Supremely-tough Glass Performs Under Pressure” →

Little Ionic Thruster Blows Out Candles With Ease

August 22, 2023 by Donald Papp 24 Comments

Want to generate some thrust by way of an exposed high voltage discharge that looks great when you turn down the lights? [Integza] has a video showing how to do exactly that with some simple components. His little thruster manages to blow out candles at surprising distances before being pressed into service propelling a model boat.

Here’s how it works: ionic wind is generated when a strong enough electric field causes nearby air to ionize, for example from sharp tips of a conductor carrying a high enough voltage. This discharge creates ionized air molecules with an electrical charge matching the polarity of the nearby conductor. Because matching polarities repel one another, the small cloud of ionized air molecules are repelled from both the nearby conductor, as well as from each other.

The result is a wind-like force from a device with no moving parts, and if the parts are structured right, it’ll blow out a candle with ease. [Integza] attached a cheap DC high-voltage transformer to a nickel strip cut into sharp points and rolled into a circlet. The other half of the thruster — in contrast to the thin crown of sharp points — is a smooth ring shaped a little like a thruster nozzle. 3D models of the parts are available online should you wish to try it yourself without all the trial and error of trying to optimize.

In an effort to minimize mass, [Integza] electroplates a 3D-printed version of the large ring with great results, spraying it with graphite first to make it conductive. Cheap and safe copper electroplating is entirely within the reach of hobbyists, and the resulting unit does a pretty nice job. You can watch it in action in the video, embedded below.

Continue reading “Little Ionic Thruster Blows Out Candles With Ease” →

3D Printing With Clay, Thanks To Custom Extruder

August 22, 2023 by Donald Papp 14 Comments

When it comes to 3D printing clay, there are a lot of challenges to be met. An extruder capable of pushing clay is critical, and [davidsfeir] has an updated version suitable for an Ender 3 printer. This extruder is based on earlier designs aimed at delta printers, but making one compatible with an Ender 3 helps keep things accessible.

Lightly pressurized clay comes in via the clear tube. Air escapes out the top (motor side) while an auger homogenizes the clay and pushes it out the nozzle.

What’s special about a paste extruder that can push clay? For one thing, clay can’t be stored on a spool, so it gets fed into the extruder via a hose with the help of air pressure. From there, the clay is actually extruded with the help of an auger that takes care of pushing the clay down through the nozzle. The extruder also needs a way to deal with inevitable air bubbles, which it does by allowing air to escape out the narrow space at the top of the assembly while clay gets fed downward.

[davidsfeir] was greatly inspired by the work of clay-printing pioneers [Piotr Waśniowski] and his de-airing clay extruder, and [Jonathan Keep], who has documented 3D printing with clay comprehensively in a freely-available PDF. You can check out more of [david]’s designs on his Instagram page.

There are so many different aspects to printing with clay or clay-like materials that almost every part is ripe for innovation. For example, we’ve seen wild patterns result from sticking a thumping subwoofer under a print bed.

Weird Lens Allows Light Field Passthrough For VR Headset

August 10, 2023 by Donald Papp 16 Comments

Light Fields are a subtle but critical element to making 3D video look “real”, and it has little to do with either resolution or field of view. Meta (formerly Facebook) provides a look at a prototype VR headset that provides light field passthrough video to the user for a more realistic view of their surroundings, and it uses a nifty lens and aperture combination to make it happen.

As humans move our eyes (or our heads, for that matter) to take in a scene, we see things from slightly different perspectives in the process. These differences are important cues for our brains to interpret our world. But when cameras capture a scene, they capture it as a flat plane, which is different in a number of important ways from the manner in which our eyes work. A big reason stereoscopic 3D video doesn’t actually look particularly real is because the information it presents lacks these subtleties.

Continue reading “Weird Lens Allows Light Field Passthrough For VR Headset” →

Why VR As Monitor Replacement Is Likely To Be Terrible For A While Yet

August 9, 2023 by Donald Papp 26 Comments

Putting on a headset and using virtual monitors in VR instead of physical ones is a use case that pops up, but is it really something feasible? [Karl Guttag], who has long experience and a deep understanding of the technical challenges that face such devices, doesn’t seem to think so.

In his writeup [Karl] often focuses on the recently-unveiled high resolution Apple Vision Pro, but the issues he discusses transcend any particular product. His article is worth the read for anyone with an interest in these issues, but we’ll summarize some main points here. Continue reading “Why VR As Monitor Replacement Is Likely To Be Terrible For A While Yet” →

3D Print Your Own Seiko-Style “Magic Lever” Energy Harvester

August 9, 2023 by Donald Papp 20 Comments

Back in 1956, Seiko created their “magic lever” as an integral part of self-winding mechanical watches, which were essentially mechanical energy harvesters. The magic lever is a type of ratcheting arrangement that ensures a main gear only ever advances in a single direction. [Robert Murray-Smith] goes into detail in this video (here’s a link cued up to 1:50 where he begins discussing the magic lever)

There is a lot of naturally-occuring reciprocal motion in our natural world. That is to say, there is plenty of back-and-forth and side-to-side, but not a lot of round-and-round. So, an effective mechanism for a self-winding watch needed a way to convert unpredictable reciprocal motion into a unidirectional rotary one. The magic lever was one way to do so, and it only has three main parts. [Robert] drew these up into 3D models, which he demonstrates in his video, embedded below.

The 3D models for Seiko’s magic lever are available here, and while it’s fun to play with, [Robert] wonders if it could be integrated into something else. We’ve certainly seen plenty of energy harvesting projects, and while they are mostly electrical, we’ve also seen ideas about how to harvest the energy from falling raindrops.

Continue reading “3D Print Your Own Seiko-Style “Magic Lever” Energy Harvester” →