This week Jonathan Bennett and Simon Phipps sit down with Simon Kelley to talk about Dnsmasq! That’s a piece of software that was first built to get a laptop online over LapLink, and now runs on most of the world’s routers and phones. How did we get here, and what does the future of Dnsmasq look like? For now, Dnsmasq has a bus factor of one, which is a bit alarming, given how important it is to keeping all of us online. But the beauty of the project being available under the GPL is that if Simon Kelley walks away, Google, OpenWRT, and other users can fork and continue maintenance as needed. Give the episode a listen to learn more about Dnsmasq, how it’s tied to the Human Genome Project, and more!
When the people of Earth set up bases on the moon, you can imagine that 3D printing will be a key enabling technology. Of course, you could ship plastic or other filament at great cost. But what if you could print with something you can already find on the moon? Like moon dust. NASA thinks it is possible and has been doing tests on doing just that. Now [Virtual Foundry] wants to let you have a shot at trying it yourself. It doesn’t really contain moon dust, but their Basalt Moon Dust Filamet has a similar composition. You can see a video about the material below.
It isn’t cheap, but it is probably cheaper than going up there to get some yourself. At least for now. The company is known for making PLA with various metal and ceramic materials. Like their other filaments, you print it more or less like PLA, although you need a large hardened nozzle, and they suggest a prewarmer to heat the filament before going to the hot end.
[eBender] was travelling India with friends, when one got sick. Unable to find a thermometer anywhere during COVID, they finally ended up in a hospital. After being evacuated back home, [eBender] hatched an idea to create a portable gadget featuring a few travel essentials: the ability to measure body temperature and heart rate, a power bank and an illumination source. The scope evolved quite a lot, with the concept being to create a learning platform for environmental multi-sensor fusion. The current cut-down development kit hosts just the air quality measurement components, but expansion from this base shouldn’t be too hard.
ML for Hackers: Fiddle with that Tensor Flow
This project’s execution is excellent, with a hexagon-shaped enclosure and PCBs stacked within. As everyone knows, hexagons are the bestagons. The platform currently hosts SCD41 and SGP41 sensors for air quality, a BME688 for gas detection, LTR-308 for ambient light and motion, and many temperature sensors.
On top sits a 1.69-inch IPS LCD, with an OLED display on the side for always-on visualization. The user interface is completed with a joystick and a couple of buttons. An internal blower fan is ducted around the sensor array to pull not-so-fresh air from outside for evaluation. Control is courtesy of an ESP32 module, with the gory details buried deep in the extensive project logs, which show sensors and other parts being swapped in and out.
On the software side, some preliminary work is being done on training TensorFlow to learn the sensor fusion inputs. This is no simple task. Finally, we would have a complete package if [eBender] could source a hexagonal LCD to showcase that hexagon-orientated GUI. However, we doubt such a thing exists, which is a shame.
There are many air quality sensors on the market now, so we see a few hacks based on them, like this simple AQ sensor hub. Let’s not forget the importance of environmental CO2 detection; here’s something to get you started.
Boats come in all shapes and sizes. We have container ships, oil tankers, old-timey wooden sailing ships, catamarans, trimarans, and all sorts besides. Most are designed with features that give them a certain advantage or utility that justifies their construction for a given application.
The roller ship, on the other hand, has not justified its own repeat construction. Just one example was ever built, which proved unseaworthy and impractical. Let’s explore this nautical oddity and learn about why it didn’t make waves as its inventor may have hoped.
It is a common grade school experiment to wind some wire around a screw, power it up, and watch it pick up paper clips or other ferrous materials. It is also grade school science to show that neither an electromagnet nor a permanent magnet will pick up nonferrous items like copper or aluminum. While technically not an electromagnet, it is possible to build a similar device that will weakly pull on copper and aluminum, and [Cylo] shows us how it works in a recent video you can see below.
The device sure looks like an electromagnet made with magnet wire and a steel core. But when he shows the ends of the core, you’ll see that the side that attracts aluminum has a copper ring embedded in it. The coil is fed with AC.
The magnetic field from the coil induces an opposite field in the copper ring that is out of phase with the exciting field. The two fields combine to produce a force on the metal it interacts with. This is often referred to as a shaded pole, and the same technique can help AC motors self-start as well as hold in relays driven by AC. If you want to see much more about aluminum floating on a magnetic field, check out the 1975 video from [Professor Laithwaite] in the second video below.
Though it suffered through decades of naysayers, these days you’d be hard pressed to find anyone who would still argue that the commercialization of space has been anything but a resounding success for the United States. SpaceX has completely disrupted what was a stagnant industry — of the 108 US rocket launches in 2023, 98 of them were performed by the Falcon 9. Even the smaller players, such as Rocket Lab and Blue Origin, are innovating and bringing new technologies to market at a rate which the legacy aerospace companies haven’t been able to achieve since the Space Race.
So it’s no surprise that other countries are looking to replicate that success. Japan in particular has been following NASA’s playbook by offering lucrative space contracts to major domestic tech companies such as Mitsubishi, Honda, NEC, Toyota, Canon, Kyocera, and Sumitomo. Over the last several years this has resulted in the development of a number spacecraft and missions, such as the Hakuto-R Moon lander. It’s also laid the groundwork for exciting future projects, like the crewed lunar rover Toyota and Honda are jointly developing for the Artemis program.
But so far there’s been a crucial element missing from Japan’s commercial space aspirations, an orbital booster rocket. While the country has state-funded launch vehicles such as the H-IIA and H3 rockets, they come with the usual bureaucracy one would expect from a government program. In comparison, a privately developed and operated booster holds the promise of reduced costs and a higher launch cadence, especially if there are multiple competing vehicles on the market.
With the recent test flight of Space One’s KAIROS rocket, that final piece of the puzzle may finally be falling into place. While the launch unfortunately failed shortly after liftoff, the fact that the private rocket was able to get off the ground — literally and figuratively — is a promising sign of what’s to come.
Although the components of wood – cellulose and lignin – are exceedingly cheap and plentiful, combining these into a wood-like structure is not straightforward, despite many attempts to make these components somehow self-assemble. A recent attempt by [MD Shajedul Hoque Thakur] and colleagues as published in Science Advances now may have come closest to 3D printing literal wood using cellulose and lignin ink, using direct ink writing (DIW) as additive manufacturing method.
Microstructures of 3D printed wood after printing and post-printing operations. (Credit: Thakur et al., 2024)
This water-based ink was created by mixing TOCN (tempo-oxidized cellulose nanofiber), a 10.6 wt % aqueous CNC (cellulose nanocrystals) and lignin in a 15:142:10 ratio, giving it roughly the viscosity of clay. The purpose of having both TOCNs and CNCs is to replicate the crystalline and amorphous cellulose elements of wood-based cellulose.
This ink was printed from a syringe head (SDS-60) installed in a Hyrel 3D Engine HR 3D printer. This printer is much like your average FDM printer, just targeting bioprinting and a wide range of heads to print and handle various attachments in a laboratory setting. The ink was extruded into specific shapes that were either freeze dried to get rid of the liquid component, or additionally also heated (at 180°C), with a third set of samples put into a hot press. These additional steps seem to promote the binding of the lignin and create a more durable result.
