Halbach Array Makes Magnets Strong, Weak

July 16, 2023 by Al Williams 16 Comments

If you want a strong magnet, the obvious answer is to buy one. However, for a variety of reasons, you might want to combine several smaller magnets. There are a few ways to do this, but the Halbach array, as [wannabemadsci] explains, allows you to make an array of magnets where one side is very strong, and the other side is very weak.

The example uses a 3D-printed housing and five cube magnets. To form a Halbach array, the poles of the magnets are in a specific orientation that effectively rotates ninety degrees for each — in this case — cube.

Continue reading “Halbach Array Makes Magnets Strong, Weak” →

Exploring A New Frontier: Desktop EDM Is Coming

July 5, 2023 by Tom Nardi 27 Comments

To say that desktop 3D printing had a transformative effect on our community would be something of an understatement. In just a decade or so, we went from creaky printers that could barely extrude a proper cube to reliable workhorses that don’t cost much more than a decent cordless drill. It’s gotten to the point that it’s almost surprising to see a project grace these pages that doesn’t include 3D printed components in some capacity.

There’s just one problem — everything that comes out of them is plastic. Oh sure, some plastics are stronger than others…but they’re still plastic. Fine for plenty of tasks, but certainly not all. The true revolution for makers and hackers would be a machine that’s as small, convenient, and as easy to use as a desktop 3D printer, but capable of producing metal parts.

If Cooper Zurad has his way such a dream machine might be landing on workbenches in as little as a month, thanks in part to the fact that its built upon the bones of a desktop 3D printer. His open source Powercore device allows nearly any 3D printer to smoothly cut through solid metal using a technique known as electrical discharge machining (EDM). So who better to helm this week’s Desktop EDM Hack Chat?

Continue reading “Exploring A New Frontier: Desktop EDM Is Coming” →

Quetzal-1 Satellite Goes Open Source

July 4, 2023 by Jonathan Bennett 30 Comments

Back in 2020, students from Universidad Del Valle De Guatemala (UVG) pulled off a really impressive feat, designing and building a CubeSat that lasted a whopping 211 days in orbit. In addition to telemetry and radio equipment, it carried a black-and-white camera payload.

But it turns out space is hard. The first pictures were solid black or white, with the automatic exposure process failing pretty badly. A pair of good pictures were taken by waiting until the satellite was passing over Guatemala during sunrise or sunset. A hung I2C bus led to battery drain, and the team tried a system reset to clear the hung state. Sadly the craft never came back to life after the reset, likely because of one of the Lithium-Ion battery cells failed completely in the low charge state.

That was 2020, so why are we covering it now? Because the project just released a massive trove of open source design documents, the software that ran on the satellite and ground station, and all the captured telemetry from the flight. It’s the ultimate bootstrap for anyone else designing a CubeSat, and hopefully provides enough clues to avoid some of the same issues.

Even though the mission had problems, it did achieve a lot of milestones, including the first picture of Earth taken by a Central American satellite. Even coming online and making radio contact from orbit to an earthbound station is quite a feat. The team is already looking forward to Quetzal-2, so stay tuned for more!

And if you want the details on the Quetzal-1 design, and what went wrong with the electrical system, both PDF papers have been released. Seeing more open source in space is an encouraging development, and one that should continue to grow as the cost of payloads to orbit continues to fall. We’ve covered the UPSat satellite, the PyCubed framework, and even the RTL-SDR for listening to satellite radio traffic.

Ice Wrenchers, Wrencher Chocolates, And The Vaquform DT2

July 3, 2023 by Jenny List 9 Comments

What do you do when you find some friends have bought a vacuum forming machine? Make novelty chocolates and ice cubes, of course! This was my response when I had the opportunity to play with a Vaquform DT2 all-in-one vacuum forming machine, so what follows is partly a short review of an exciting machine, and partly an account of my adventures in edible merchandise creation.

The vaquform machine, on a neutral white background — The Vaquform machine in all its glory.

Vacuum forming, the practice of drawing a sheet of heat-softened plastic film over a model to make a plastic shell copy of it, is nothing new in our community. It’s most often found in hackerspaces in the form of home made vacuum forming tables, and usually requires quite a bit of experimentation to get good results. The Vaquform machine I was lucky enough to be able to try is an all in one machine that puts the whole process into a compact desktop machine of similar size to a typical 3D printer. It’s a machine of two parts with a moveable carriage between them for the plastic sheet; a vacuum table on its base, and a heater unit suspended above it. The unique selling point is that it’s an all-in-one computer controlled unit that does as much as possible for you, it simply requires the user to place a sheet in the carriage and follow the instructions.

When I first saw the machine I didn’t really have anything to try it with, so of course I resorted to producing a Wrencher or two. Because what it makes are essentially moulds, it made sense to produce something Wrencher-shaped with them, and thus the chocolate and ice plan formed. The first mould was made with laser-cut Wrenchers in 2mm acrylic, stacked on two more layers of uncut acrylic to make a bar with an inset Wrencher on top, while the second one used a 3D-printed array of larger stand-alone Wrenchers with channels between them. Would my first attempt at vacuum forming make usable moulds or not? Only one way to find out. Continue reading “Ice Wrenchers, Wrencher Chocolates, And The Vaquform DT2” →

DIY Picosatellites Hack Chat

June 19, 2023 by Dan Maloney 10 Comments

Join us on Wednesday, June 21 at noon Pacific for the DIY Picosatellites Hack Chat with Nathaniel Evry!

Building a satellite and putting it in orbit was until very recently something only a nation had the resources to accomplish, and even then only a select few. Oh sure, there were a few amateur satellites that somehow managed to get built on a shoestring budget and hitch a ride into space, and while their stories are deservedly the stuff of legends, satellite construction took a very long time to be democratized.

Fast forward a half-dozen or so decades, and things have changed dramatically. Satellite launches are still complex affairs — it’s still rocket science, after all — but the advent of the CubeSat format and the increased tempo of launches, both national and commercial, has pushed the barriers to private, low-budget launches way, way down. So much so, in fact, that the phrase “space startup” is no longer something to snicker about.

One such group of space entrepreneurs is Quub, Inc., a small company in Lancaster, Pennsylvania which is looking to build and fly a constellation of microsatellites to monitor Earth’s environment in real-time. They’re building sats and signing launch deals using consumer-grade technology and modularized construction, and we’re lucky enough to have Nathaniel Evry, their Chief Research Officer, stop by the Hack Chat. If you’ve ever wondered what it takes to build hardware that can stand the rigors of launch and then perform a task in space, you’ll want to tune in for this one.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, June 21 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter. Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

These Illusions Celebrate Exploiting Human Senses

June 16, 2023 by Donald Papp 7 Comments

Illusions are perceptual experiences that do not match physical reality, and the 2023 Illusion of the Year contest produced a variety of nifty ones that are worth checking out. A video for each is embedded below the break, but we’ll briefly explain each as well.

Some of the visual illusions play with perspective. One such example happens to be the contest winner: Platform 9 3/4 has a LEGO car appear to drive directly through a wall. It happens so quickly it’s difficult to say what happened at all!

Another good one is the Tower of Cubes, which appears as two stacks of normal-looking hollow cubes, but some of the cubes are in fact truly bizarre shapes when seen from the side. This is a bit reminiscent of the ambiguous cylinder illusion by Japanese mathematician and artist [Kokichi Sugihara].

Cornelia is representative of the hollow face illusion, in which a concave face is perceived as a normal convex one. (Interestingly this illusion is used to help diagnose schizophrenia, as sufferers overwhelmingly fail to perceive the illusion.)

The Accelerando Illusion is similar to (but differs from) an auditory effect known as the Risset Rhythm by composer Jean-Claude Risset. It exploits ambiguities in sound to create a dense musical arrangement that sounds as though it is constantly increasing in tempo.

The Buddha’s Ear Illusion creates the illusion of feeling as though one’s earlobe is being stretched out to an absurd length, and brings to mind the broader concept of body transfer illusion.

While it didn’t appear into the contest, we just can’t resist bringing up the Thermal Grill Illusion, in which one perceives a painful burning sensation from touching a set of alternating hot and cold elements. Even though the temperatures of the individual elements are actually quite mild, the temperature differential plays strange tricks on perception.

A video of each of the contest’s entries is embedded below, and they all explain exactly what’s going on for each one, so take a few minutes and give them a watch. Do you have a favorite illusion of your own? Share it in the comments!

Continue reading “These Illusions Celebrate Exploiting Human Senses” →

NASA Team Sets New Space-to-Ground Laser Communication Record

June 9, 2023 by Joseph Long 13 Comments

[NASA] and a team of partners has demonstrated a space-to-ground laser communication system operating at a record breaking 200 gigabit per second (Gbps) data rate. The TeraByte InfraRed Delivery (TBIRD) satellite payload was designed and built by [MIT Lincoln Laboratory]. The record of the highest data rate ever achieved by a space-to-Earth optical communication link surpasses the 100 Gbps record set by the same team in June 2022.

TBIRD makes passes over an ground station having a duration of about six-minutes. During that period, multiple terabytes of data can be downlinked. Each terabyte contains the equivalent of about 500 hours of high-definition video. The TBIRD communication system transmits information using modulated laser light waves. Traditionally, radio waves have been the medium of choice for space communications. Radio waves transmit data through space using similar circuits and systems to those employed by terrestrial radio systems such as WiFi, broadcast radio, and cellular telephony. Optical communication systems can generally achieve higher data rates, lower loses, and operate with higher efficiency than radio frequency systems. Continue reading “NASA Team Sets New Space-to-Ground Laser Communication Record” →