Wigglegrams With A Pinhole Camera

A pinhole camera is almost a rite of passage in photography, given that you can make one so easily with little more than a cardboard box and enough tape to keep the light from coming through the cracks. [Socialmocracy] has made one that’s 3D printed, and it’s a nice design that takes 4″ by 5″ photographic paper. The shutter is held on with magnets, and the lid is attached with thumbscrews.

As neat as printed pinhole cameras are, it’s not as though they’re particularly uncommon. What makes this one stand out from the rest is that it’s actually two cameras in one. One box, two cameras, side by side. Landscape format and it’s a pair of panoramic cameras, while in portrait mode it’s a stereo camera. Even the simplest of cameras can do wigglegrams!

We like this camera, because it manages to add something to such a simple formula.. He’s taking comments on whether to release the STLs, so drop in your two cents.

Continue reading “Wigglegrams With A Pinhole Camera”

There’s More To Global Positioning Than Just GPS

The Global Positioning System (GPS) was developed by the United States military in the 1970s, but it wasn’t long before civilians all over the planet started using it. By the early 2000s the technology was popping up in consumer devices such as mobile phones, and since then its become absolutely integral to our modern way of life.

But although support for GPS in our gadgets is nearly ubiquitous, it’s not the only option when it comes to figuring out where you are on the globe. As you might imagine, not everyone was thrilled with building their infrastructure around one of Uncle Sam’s pet projects, and so today there are several homegrown regional and global satellite navigation systems in operation.

As a follow-up to our recent dive into the ongoing GPS upgrades, let’s take a look at some of the other satellite positioning systems and who operates them.

Continue reading “There’s More To Global Positioning Than Just GPS”

University Of Utah’s TRIGA Research Reactor Set To Produce Electricity

Research reactors come in many forms and sizes, with the TRIGA class being commonly found at universities. The TRIGA reactor at the University of Utah was installed in 1975, and for the past half century the thermal energy it produced was bled off into cooling systems. Now for a world’s first, the reactor will be used to generate electricity instead.

A TRIGA reactor core, with the blue glow from Cherenkov radiation. (Source: DoE, Wikimedia)
A TRIGA reactor core, with the blue glow from Cherenkov radiation. (Source: DoE, Wikimedia)

What makes the TRIGA design so practical for small research reactors is its inherent safety due to the use of uranium zirconium hydride (UZrH) fuel, which imposes a strong negative thermal coefficient on the reactivity. Along with no need for any kind of containment, these pool-type, water-cooled reactors thus allow for a pretty good look at the literal internals of the reactor core.

Their thermal power outputs range from 0.1 – 16 MWth, with the University of Utah reactor generating on the low end of the scale here, at 50 kWth. This energy will be partially used by a generator that has been developed by Elemental Nuclear, a startup company who looks to be trying to commercialize TRIGA fuel for microreactors with sodium coolant.

The installation at this TRIGA reactor should thus be seen as a proof-of-concept for Elemental Nuclear’s generator design, which uses a closed Brayton cycle with helium gas to generate an output of about 2-3 kWe from the ~13 kW generated by the turbine. This generated power will – of course – be used to power some racks with GPUs for ‘AI’ tasks. If successful, it could show the way for TRIGA-based microreactors to power datacenters.


Top image: the TRIGA reactor during a tour. (Credit: University of Utah)

This Az-El Mount Is Worth Following

Communication with satellites often involves the use of high-gain directional antennas coupled with careful positioning to find and track the target. With a geostationary satellite the mount is either fixed or a single-axis polar mount, but when the craft is moving in a different orbit it becomes more of a challenge to stay locked on. An azimuth-elevation mount is needed to cover the whole sky, and [Ham Radio Passion] has one as a work in progress. It’s 3D printed and looks straightforward, making it a project to watch.

An az-el mount has two parts, the first being a turntable to set the azimuth, and the second being a horizontal rotating axis to set the elevation. He’s mounting the antenna to a piece of aluminium extrusion and driving it through a set of 3D printed gears driven from a 360 degree servo with a worm drive. He explains why the servo makes more sense to him here.

The result is not yet a finished project, but it shows enough promise to make it worth keeping an eye on. It’s by no means big enough for a huge antenna array, but we can imagine antennas for higher frequencies would be well within its capabilities. Meanwhile it’s certainly not the first az-el mount we’ve seen.

Continue reading “This Az-El Mount Is Worth Following”

How To Better Enjoy VR On Linux

Linux folks are used to having to roll many of their own solutions, and better Linux desktop usability is a goal of the WayVR project, which aims to provide desktop control and app launching from within a VR session.

VR applications can already stream from Linux to standalone headsets with projects like WiVRn, but what WayVR does is let one launch programs and access desktop screens within VR. Put another way, instead of the headset being limited to acting as a pseudo-monitor that only receives the output of an already-running VR application, the headset and controllers can now be used to interact with one’s computer as if one were physically sitting at it. Controls and user interface are highly flexible and help users to do anything they need — including clicking, typing, and launching applications. It’s a considerable step forward for convenience and general usability.

Naturally, when it comes to using a computer from within VR there is plenty of unexplored territory regarding user interfaces. It’s fertile ground for experimentation in everything from DIY headsets to ways to input text without a keyboard, so if you enjoy working on the frontiers of such things, it’s a good scene to dive into.

Learn Programming Without A Computer

Presumably aimed at children, NHK World’s Texico program teaches the main ideas about programming without actually using a computer. Instead, it uses items like a toy train, playing cards, and other gadgets to teach concepts such as analysis, combination, simulation, abstraction, and more.

There are ten episodes in English and French. Some of them are more about critical thinking, which, admittedly, is important for solving problems in general with or without a computer. For example, a “magic” trick relies on the observation that tearing a sheet of paper into nine rectangular pieces will mean each piece has at least one perfectly straight edge except for the center piece.

Continue reading “Learn Programming Without A Computer”

A 1947 Radio Gets A Face Lift

We’ve all done it. We spy an old radio at a garage sale or resale shop. We know someone should bring it back to life, but it looks like a project, so we pass it by. Not [Ken] from [Ken’s Shop]. He found an Arvin 664A AM radio from 1947 in what appears to be a home-built cabinet and decided to bring it back to life.

From what we could find, the original case was a white plastic, not the wood box it is in today. So the first challenge was simply getting inside to see what was going on. Continue reading “A 1947 Radio Gets A Face Lift”