Trying A New Radial Impeller Design For Quadcopters

Even if the world has already settled on plain old propellers as the way to make quadcopter drones fly, this doesn’t mean that you cannot give other designs a shake to see what kind of flying performance they result in. For example impeller designs that depart radically from standard propellers – themselves a sub-category of axial impellers – and go radically radial instead as in this design by [quadmovr] with accompanying demonstration video.

This is itself a remix of a design by [Baba] to make it fit the target 1750KV T-mount motor. As for whether this is a design that you want to slap on your own quadcopter, the obvious disadvantage is that it’s much heavier than regular propellers.

Weighing [quadmovr]’s drone without battery pack and with these 3D-printed PETG impellers shows them to weigh 189 grams. This compares to 141 grams with the standard three-bladed propellers, or a hefty 12.8 gram weight penalty per impeller. Naturally this translates into less flying time, so what are the advantages?

The noise profile of the impeller design is definitely more pleasant, and much like novice quadcopters with the protective ring around the propellers these impellers should be more robust. On the other hand increased mass adds to inertia, and there is a lot more surface area with the air to add drag, so despite the absolutely sick moves that [quadmovr] pulls off with both impeller configurations in the video one has to admit that regular three-blade propellers do have the edge here.

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A blueish grey plastic enclosure sits next to a blue and black servo, silver Li-ion battery, a GPS module board, an LCD, a small metal lever, and ESP32S3 board.

Pedal Harder For Affordability

In the US, among other places, housing costs are skyrocketing. It can sometimes be difficult to get a feel for the scale of the issue and how it hits neighborhoods differently. [Justin Blinder] has designed a device to help people get a more visceral understanding of the problem.

In New York City, Citi Bikes are everywhere in the city’s transportation landscape. [Blinder] used a GPS module plugged into an ESP32S3 to vary the amount of resistance on one of these bikes by actuating the front brake with a servo. As a rider takes the bike through different neighborhoods, the resistance varies in proportion to the rent burden experienced there.

[Blinder] explains, “One of the main technical challenges was calibrating this relationship so that the changes were physically noticeable without feeling abrupt or unsafe.” As rent burden is merely the percentage of income taken up by rent in an area (by the block in this dataset), it is only one indicator of the additional friction a family might feel in an area, but a useful one to at least begin to convey the disparities in the urban environment. We really like how this connects abstract statistics to something more experiential.

If you’re looking for some other bike hacks, how about wireless brakes or a sleeper e-bike with a solenoid display?

via Next City

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The First Floating Nuclear Power Station

Nuclear power really hit its stride in the 1950s. In the post-war period, there was a rush to develop peaceful uses for splitting the atom, beyond its application as a weapon of war. Soon enough, nuclear reactors were hooking up to power grids and helping propel ships and submarines around the globe.

Eventually, this led to an obvious idea—what if a ship with a reactor could serve as a floating nuclear power station? That question would be answered in the mid-1960s, with an American project of some strategic importance.

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The RP2350 Does 1080p

Coaxing a DVI signal out of a microcontroller to drive a DVI or HDMI screen has been possible for a while now, but limitations in what the devices can do has, in turn, placed a limit on the resolution that can be delivered. Now [Aaron Gayle] has broken through a barrier by generating 1080p video from an RP2350. The previous best from Raspberry Pi Pico-class microcontrollers was 720p, which an RP2040 could deliver. The 2350 is faster and has faster peripherals, but even then, to reach this resolution he had to overclock it to 372 MHz. For all the impressive achievement, there’s still a limitation. Lacking space for a framebuffer, he generates scanline by scanline, a technique we associate more with 8-bit computers from the 1980s.

The 1080p video code is part of a package called TVtop, a board game in which the game board is displayed on the TV and whose players interact from their phones via Wi-Fi. For that reason, there’s an ESP32 in the project too, though it has nothing to do with the video hack.

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DIY Router On X86 E-Waste: OpenWrt And OPNsense

In previous installments of this series we looked at how creating a DIY router using an e-waste-level PC has changed over the years, before attempting to boot OpenWrt for x86 on it. After an initial SD card booting failure on one system, another system with a newer mainboard – an Intel Board D2500CC – was used which happily booted OpenWrt from an SD card inserted into a USB card reader.

Unfortunately, OpenWrt didn’t see any usable Ethernet interfaces despite having no less than four Intel Ethernet controllers and two hooked up to active networks. After recently getting back to the project, I found out why both onboard Intel 82574L Ethernet controllers didn’t show up in OpenWrt: the drivers for the Intel 82574L controllers are in the e1000e driver package, while only the e1000 package is present in the provided x86 image. This issue persists in the ‘generic’ image profile to this day.

Yet rather than diving head-first into building my own image that includes the kmod-e1000e package, I decided to give OPNsense a shake first.

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Searching For Dark Matter With A Levitating Magnet

Much of science is performed through inference, with the readings on instruments, a flash of light in heavy water, or the results of parsing through terabytes of sensor data after a particle accelerator collision either backing up a proposed scenario or weakening its foundations.

In the case of so-called dark matter, this is even more relevant, as we are talking about a proposed form of matter whose most pertinent feature is that it doesn’t interact with anything else except through gravity. This is where the wiggling of a levitating magnet may be the key to detecting it.

In this experimental setup by Rice University and Dutch researchers at the Leiden Institute, a tiny permanent magnet the size of a grain of sand is levitated above a superconductor, surrounded by highly sensitive detectors that should be able to spot even minuscule movements. So far, they have collected a month’s worth of data, with no conclusive results yet.

Even if they don’t detect any ‘knocks’ on this tiny levitating magnet, it will still help refine existing models of what dark matter’s properties might be. For the next phase of this research, they’ll add more of these sensors, which will also make it easier to distinguish background noise from any unusual readings.

We’ve previously talked about [Vera Ruben]’s contributions to the hunt for dark matter and the mysteries that prompted the idea that it might exist.

The Sinclair Spectrum Gets A Desktop GUI

Of the popular 1980s 8-bit computers, it’s fair to say that Sinclair’s ZX Spectrum punched above its weight. Sir Clive’s love of squeezing more functionality out of less hardware meant the compromises he made left it less powerful than competitors from Apple, Commodore, or Acorn. Still, the brightest programmers of the age took the little machine to heart and made it do some very impressive things. A desktop GUI, though, surely that would be pushing things too far. Never say never because now [mindbox77] has done it.

ZXdesk is an assembly language program for the 48k Spectrum that gives you something that looks a lot like GEM. It’s got all the things you’d expect from a desktop GUI, with menus, windows, and applications, and we find ourselves suitably impressed.

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