Lifeboat Foundation

Ten years ago the concept of having on our desks an affordable 3D printer knocking out high quality reproducible prints, with sub-mm accuracy, in a wide range of colours and material properties would be the would be just a dream. But now, it is reality. The machines that are now so ubiquitous for us hackers, are largely operating with the FDM principle of shooting molten plastic out of a moving nozzle, but they’re not the only game in town. A technique that has also being around for donkeys’ years is SLS or Selective Laser Sintering, but machines of this type are big, heavy and expensive. However, getting one of those in your own ‘shop now is looking a little less like a dream and more of a reality, with the SLS4All project by [Tomas Starek] over on hackaday.io.

[Tomas] has been busy over the past year, working on the design of his machine and is now almost done with the building and testing of the hardware side. SLS printing works by using a roller to transfer a layer of powdered material over the print surface, and then steering a medium-power laser beam over the surface in order to heat and bond the powder grains into a solid mass. Then, the bed is lowered a little, and the process repeats. Heating of the bed, powder and surrounding air is critical, as is moisture control, plus keeping that laser beam shape consistent over the full bed area is a bit tricky as well. These are all hurdles [Tomas] has to overcome, but the test machine is completed and is in a good place to start this process control optimisation fun.

Hardware-wise, the frame is the usual aluminium extrusion and 3D printed affair, with solid aluminium plates all over the place where needed. Electronics are based around a Raspberry Pi (running Klipper) with a BigTreeTech 1.4 turbo mainboard handling the interfacing. The 5W blue laser is steered over the powder surface using a pair of galvanometers, which sounds easier to get right than it will be — we fully expect there to be some ‘fun’ to control the spot size and shape as well as ensure that it stays consistent over the full area of the build surface. Definitely fun times, and fingers crossed that [Tomas] irons out the details and gets some good prints out of it soon!

Bill Browder is the founder and CEO of Hermitage Capital, which advised the largest foreign investment fund in Russia — until 2005. Browder is also the author of “Red Notice” detailing his expulsion from Russia and the arrest, torture and then death of his attorney, Sergei Magnitsky, who was being held in Russian custody.

Since then, Russian President Vladimir Putin has issued several arrest warrants for Browder, accusing him of financial fraud. However, Interpol deemed each attempt as politically motivated and rejected Putin’s calls for him to be extradited to Russia. Browder was arrested once in Europe, but was released hours later after Interpol declared the charges political.

Continue reading “Bill Browder says only Putin can end war after losing ‘bet’ | NewsNation” »

Scanning electron microscopes are one of those niche instruments that most of us don’t really need all the time, but would still love to have access to once in a while. Although we’ve covered a few attempts at home-builds before, many have faltered, except this project over on Hackday. IO by user Vini’s Lab, which appears to be still under active development. The principle of the SEM is pretty simple; a specially prepared sample is bombarded with a focussed beam of electrons, that is steered in a raster pattern. A signal is acquired, using one of a number of techniques, such as secondary electronics (SE) back-scattered electrons (BSE) or simply the transmitted current into the sample. This signal can then be used to form an image of the sample or gather other properties.

The project is clearly in the early stages, as the author says, it’s a very costly thing to build, but already some of the machined parts are ready for assembly. Work has started on the drive electronics for the condenser stigmata lens. This part of the instrument takes the central part of the rapidly diverging raw electron beam that makes it through the anode, and with a couple of sets of octopole coil sets, and an aperture or two, selects only the central portion of the beam, as well as correcting for any astigmatism in the beam. By adjusting the relative currents through each of the coils, a quadrupole magnetic field is created, which counteracts the beam asymmetry.

Scanning control and signal acquisition are handled by a single dedicated card, which utilises the PIO function of a Raspberry Pi Pico module. The Pico can drive the scanning operation, and with an external FTDI USB3.0 device, send four synchronised channels of acquired sample data back to the host computer. Using PCIe connectors and mating edge connectors on the cards, gives a robust and cost effective physical connection. As can be seen from the project page, a lot of mechanical design is complete, and machining has started, so this is a project to keep an eye on in the coming months, and possibly years!

One important recent development in quantum sensing is known as quantum squeezing—a way to circumvent quantum limitations that even quantum sensors have faced in the past.

A technique from the newest generation of quantum sensors is helping scientists to use the limitations of the Heisenberg uncertainty principle to their advantage.

· They have on-board video cameras and colour sensors to aid with guidance.

· They are essentially camera-equipped, remote-controlled flying bombs that can be directed by an operator to find a target then, when ready, plunge on to it. They explode on contact, hence the “kamikaze” nickname.

Switchblades extend the range of attack on Russian vehicles and units to beyond the sight of the user. That gives them an advantage over the guided heat-seeking missiles the Ukrainians have used against Russian tanks.

New approach lays groundwork for compact 3D displays that create more realistic virtual scenes.

Researchers have demonstrated a prototype glasses-free 3D light field display system with a significantly extended viewing distance thanks to a newly developed flat lens. The system is an important step toward compact, realistic-looking 3D displays that could be used for televisions, portable electronics, and table-top devices.

Light field displays use a dense field of light rays to produce full-color real-time 3D videos that can be viewed without glasses. This approach to creating a 3D display allows several people to view the virtual scene at once, much like a real 3D object.

Technology could make it possible to use radio emissions from cell phone networks to wirelessly power sensors and LEDs.

Researchers have developed a new metasurface-based antenna that represents an important step toward making it practical to harvest energy from radio waves, such as the ones used in cell phone networks or Bluetooth connections. This technology could potentially provide wireless power to sensors, LEDs and other simple devices with low energy requirements.

“By eliminating wired connections and batteries, these antennas could help reduce costs, improve reliability and make some electrical systems more efficient,” said research team leader Jiangfeng Zhou from the University of South Florida. “This would be useful for powering smart home sensors such as those used for temperature, lighting and motion or sensors used to monitor the structure of buildings or bridges, where replacing a battery might be difficult or impossible.”

The sensor sends out electromagnetic waves in a broad beam, which are intercepted and reflected back by objects (or people) in their path.

Google has patented technology that will let users control its smartwatches and earbuds by simply touching their skin.

The patent titled “Skin interface for Wearables: Sensor fusion to improve signal quality” was spotted by folks over at LetsGoDigital. It details tech that users can use to operate wearable devices using skin gestures.

Patent documents show that users can swipe or tap the skin near the wearables in order to control them. The gesture creates a mechanical wave that is picked up by the sensors in the wearables. The “Sensor Fusion” tech then combines this movement data collected from various sensors into an input command for the wearable.