Kritik sah

Air engines are a common occurrence here on Hackaday. They’re relatively novel and reasonably easy to 3D print without requiring any fluids or supporting machinery. For example, [Tom Stanton] took a previous air engine design, did away with the air compressor, and instead used gravity and water to create just a few PSI to run the engine . The basic setup is to have a large jug of water up somewhere high. Flexible tubing runs down to [Tom’s] custom acrylic pressure chamber. A little CNC-ing and some epoxy made a solid chamber, and we’re happy to report that [Tom] did some initial simulation before construction to make sure he wasn’t accidentally building a bomb. Some back of the napkin math showed that he could expect around 0.6 bar (around eight psi) with his setup. His first test showed almost precisely that. Unfortunately, [Tom] ran into some issues despite the early success. His engine would stop as it drew air and the pressure dropped, and the replenishing rate of the pressure wa...

Handcrafted gifts are special, and this one’s no exception. [pender] made a Tolkien-inspired box for his son and shared the details with us on Hackaday.io. This one-of-a-kind handcrafted box fulfills one role and does it perfectly – just like with the Doors of Durin, you have to say ‘friend’ in Elvish, and the box shall unlock for you. This box, carefully engraved and with attention paid to its surface finish, stands on its own as a gift. However, with the voice recognition function, it’s a project complicated enough to cover quite a few fields at once – woodworking, electronics, and software. The electronics are laid out in CNC-machined channels, and LED strips illuminate the “Say Friend And Come In” inscriptions once the box is ready to listen. If you’re wondering how the unlocking process works, the video embedded below shows it all. Two solenoids keep the lid locked, and in its center is a Pi Zero, the brains of the operation. With small batteries and a power-hungry board, pow...

It’s often said that the wheels of government turn slowly, and perhaps nowhere is this on better display than at NASA. While it seems like every week we hear about another commercial space launch or venture, projects helmed by the national space agency are often mired by budget cuts and indecisiveness from above. It takes a lot of political will to earmark tens or even hundreds of billions of dollars on a project that could take decades to complete, and not every occupant of the White House has been willing to stake their reputation on such bold ambitions. In 2019, when Vice President Mike Pence told a cheering crowd at the U.S. Space & Rocket Center that the White House was officially tasking NASA with returning American astronauts to the surface of the Moon by 2024, everyone knew it was an ambitious timeline. But not one without precedent. The speech was a not-so-subtle allusion to President Kennedy’s famous 1962 declaration at Rice University that America would safely land a m...

GPS has been a game-changing technology for all kinds of areas. Shipping, navigation, and even synchronization of clocks have become tremendously easier thanks to GPS. As a result of its widespread use, the cost of components is also low enough that almost anyone can build their own GPS device, and [Akio Sato] has taken this to the extreme with efforts to build a GPS tracker that uses the tiniest amount of power . This GPS tracker is just the first part of this build, known as the air station. It uses a few tricks in order to get up to 30 days of use out of a single coin cell battery. First, it is extremely small and uses a minimum of components. Second, it uses LoRa, a low-power radio networking method, to communicate its location to the second part of this build, the ground station. The air station grabs GPS information and sends it over LoRa networks to the ground station which means it doesn’t need a cellular connection to operate, and everything is bundled together in a waterpro...

In the electronics world, a little one-inch square board with castellated edges allows a lot of circuitry to be easily added in a small surface area. You can grab a prepopulated module, throw it onto your PCB of choice, and save yourself a lot of time routing and soldering. This tiny Raspberry Pi 2040 module from [SolderParty] ticks all those boxes. With all 30 GPIO broken out, 8MB of onboard flash, and a NeoPixel onboard, you have plenty to play with on top of the already impressive specs of the RPi2040. Gone are the days of in-circuit programmers, and it uses a UF2 bootloader to make it easy B to transfer new images over USB. Rust, MicroPython, Arduino, and the PicoSDK are all development options for code. All the KiCad files, BOM, schematics, and firmware are up on GitHub under a CERN license for your perusal pleasure. They’ve helpfully included footprints as well as a reference carrier board design. It is a handy little project that might be good to keep in mind or just use as ...

Grounding of electrical systems is an often forgotten yet important design consideration. Issues with proper grounding can be complicated, confusing, and downright frustrating to solve. So much so that engineers can spend their entire careers specializing in grounding and bonding. [Bsilvereagle] was running into just this sort of frustrating problem while attempting to send audio from a Nintendo Switch into a PC, and documented some of the ways he attempted to fix a common problem known as a ground loop . Ground loops occur when there are multiple paths to ground, especially in wires carrying signals. The low impedance path creates oscillations and ringing which is especially problematic for audio. When sending the Switch audio into a computer a loop like this formed. [Bsilvereagle] set about solving the issue using an isolating transformer. It took a few revisions, but eventually they settled on a circuit which improved sound quality tremendously. With that out of the way, the task ...

We’ve all had to shake jars of nail polish, model paint, or cell cultures. Mixing paint is easy – but bacteria and cells need to be agitated for hours.  Happily, laboratory tube tumblers automate this for us. The swishing action is handled with rotation. The vials are mounted at angles around a wheel. The angular offset means the tubes are inclined as they rise, and declined as they fall. This causes the liquid in the tube to slosh from one side to the other as the wheel rotates.  [Sebastian S. Cocioba] aka [ATinyGreenCell] released his plans through Tinkercad and GitHub , and with a name like Sir Tumbalot, we know he must be cultured indeed. Grab your monocles. Version 2 features a driven wheel lined with magnets to attach tube adapters, and he’s modeled 50mL and twin 15mL tube holders. The attachment points look like a simple beveled rectangle with a magnet pocket, so if you’re feeling vigorous for vials, you can whip up custom sockets and tumble any darn thing. A Trinam...