The Lilium Jet is a proposed eVTOL (electric Vertical Take Off and Landing) aircraft that the German company Lilium GmbH has claimed it will bring to the market ‘soon’, which would made it the first eVTOL aircraft in the world to enter into commercial service. As anyone who has any experience with VTOL knows, it’s a tricky subject to engineer, let alone when you want to do it fully electric. In a deep-dive video on the Lilium Jet and eVTOL in general, [John Lou] goes through the physics behind VTOL take-off, landing and flight, as well as range and general performance.
It is clear that Lilium’s presented aircraft concept has many issues, some of which are due to new and unproven technologies, while others seem to be founded in over-promising and likely under-delivering. With Lilium having signed a number of contracts to deliver the first Pioneer Edition Lilium Jets and commercial service promised by 2025, it’s hard to ignore that the first full prototype of the 7-seater Lilium Jet is supposed to fly this year.
Although as [John] points out in the video, eVTOL is not an impossible concept, it is important to remain realistic about what is physically possible, and not seek to push the boundaries. When the UK introduced its first mass-produced VTOL jet in the form of the Harrier, it too faced an uncomfortable time as bugs got ironed out. As these eVTOL aircraft would be carrying real human passengers, it’s a good place to realize that although you can pick a fight with physics, you will never come out on the winning side.
Hopefully Lilium realizes this too, and these sleek, battery-powered aircraft will truly take to the skies in a few years.
Continue reading “Will The Lilium Jet Work? A Deep-Dive Into The Physics Behind EVTOL Aircraft”
Much to the chagrin of Eastman Kodak, the world has moved on from chemical photography into the realm of digital, thanks to the ease of use and high quality of modern digital cameras. There are a few photographers here and there still using darkrooms and various chemical processes to develop film, and the most common of these use some type of chemistry based on silver to transfer images to paper. There are plenty of alternatives to silver, though, each with their unique style and benefits, like this rarely-used process that develops film using platinum.
This process, notable for its wide tonal range, delicate highlights, and rich blacks, produces only black and white photographs. But unlike its silver analog, it actually embeds the image into the paper itself rather than holding the image above the paper. This means that photographs developed in this manner are much more resilient and can last for much longer. There are some downsides to this method though, namely that it requires a large format camera and the negatives can’t be modified to produce various sized images in the same ways that other methods allow for. Still, the results of the method are striking for anyone who has seen one of these images in person.
As to why this method isn’t more common, [Matt Locke] describes a somewhat complicated history involving the use of platinum to create commercial fertilizers, which is an identical process to that of the creation of explosives, which were needed in great numbers at the same time this photographic method was gaining in popularity. While the amount of research and development that goes into creating weapons arguably generates some ancillary benefit for society, the effects of war can also serve to divert resources away from things like this.
Power tool batteries are a convenient portable power supply for all manner of different things. [Zachary Goode] noticed that Ryobi was using them to power soldering irons, but no such tool existed in the DeWalt range. Thus, he set about to build such a rig himself.
The build relies on a simple 3D-printed adapter to suck power from a DeWalt drill battery. It’s a little piece of plastic with spade terminals inserted to act as the contacts. Armed with this tool, [Zachary] included it as part of a simple compact portable soldering iron design that relies on the off-the-shelf T12-952 controller board. This allows him to use the rig with a wide variety of common soldering iron handpieces, like his favored Hakko FX-951. The design also features a lithium-ion battery protection circuit of [Zachary]’s own design, to make up for the fact that DeWalt don’t integrate them into their battery packs.
The high power density of lithium rechargeable batteries has led to a proliferation of portable soldering irons in recent years. Some are even completely handheld, with no external wires or power supplies to speak of. If you’ve been whipping up your own gear to solder on the go, don’t hesitate to drop us a line!
[RyderCalmDown] was watching a road painting vehicle lay down fresh stripes on the road one day and started thinking about the mechanism that lets it paint stripes in such a precise way. Effectively the system that paints the interspersed lines acts as a dot matrix printer that can only print at a single frequency. With enough of these systems on the same vehicle, and a little bit more fine control of when the solenoids activate and deactivate, [RyderCalmDown] decided to build this device on the back of his truck which can paint words on a roadway as he drives by. (Video, embedded below.)
Of course, he’s not using actual paint for this one; that might be prohibitively expensive and likely violate a few laws. Instead he’s using a water-based system which only leaves temporary lettering on the pavement. To accomplish this he’s rigged up a series of solenoids attached to a hitch-mounted cargo rack. A pump delivers water to each of the solenoids, and a series of relays wired to a Raspberry Pi controls the precise timing needed to make sure the device can print readable letters in much the same way a dot matrix printer works. There’s an algorithm running that converts the inputted text to the pattern needed for the dot matrix, and after a little bit of troubleshooting it’s ready for print.
Even though the printer works fairly well, [RyderCalmDown] had a problem thinking of things to write out on the roadways using this system, but it’s an impressive build based around a unique idea nonetheless. Dot matrix printers, despite being mostly obsolete, have a somewhat vintage aesthetic that plenty of people still find desirable and recreate them in plenty of other ways as well, like this 3D printer that was modified to produce dot matrix artwork.
Continue reading “Is This The World’s Largest Dot Matrix Printer?”
The Tandy Color Computer came with analog joysticks, quite unlike most computers and consoles of the early 1980s. Many games of the era actually worked best with digital input, so [Gadget Reboot] whipped up a converter board to allow Nintendo gamepads to work with the computer.
The build relies on an earlier breakout board that [Gadget Reboot] built in order to read early Nintendo gamepads and output a digital 5 V signal. Meanwhile, the Tandy Color Computer is expecting variable o-5 V signals from the X and Y axis pots in its standard joysticks. To convert the gamepad button presses into voltages for the CoCo, the build uses a CD4066 analogue switch IC. When no controller buttons are pressed, the 4066 is set up to output 2.5 V on both the X and Y axes. Pressing up or down, or left or right on the D-pad, outputs 0 V or 5 V respectively as required. This essentially lets the controller’s D-pad act as a digital joystick for a computer that never actually had one.
It’s a neat hack that might make playing certain games on the Color Computer significantly easier. It’s also just neat to interface a different controller to the old hardware. In the early 80s, computers were simple enough that this could all be achieved with a minimum of dumb circuitry.
Continue reading “Adapter Lets Digital Gamepads Work On The Tandy Color Computer”
Alan Turing proposed a test for machine intelligence that no longer works. The idea was to have people communicate over a terminal, with another real person and with a computer. If the computer is intelligent, Turing mused, most people will incorrectly identify the computer as a human. Clearly, with the advent of modern chatbots, that test is now broken. Despite the “AI” moniker, chatbots aren’t sentient or even pre-sentient, but they certainly seem that way. An AI CEO, Mustafa Suleyman, is proposing a new test: The AI has to take a $100,000 budget and earn $1,000,000.
We were a little bemused at this. By that measure, most of us aren’t intelligent, either, and it seems like this is a particularly capitalistic idea. We could probably write an Excel script that studied mutual fund performance and pull off the same trick, given enough time for the investment to mature. Is it intelligent? No. Besides, even humans who have demonstrated they can make $1,000,000 often sell their companies and start new ones that fail. How often does the AI have to succeed before we grant it person status?
Continue reading “Ask Hackaday: The Turing Test Is Dead: Long Live The Turing Test!”
What’s a tachyscope? According to [Daniel Ross], it is an animated display from an alternate timeline circa 1880. The real ones, of course, didn’t have LEDs and microcontrollers. The control unit looks like an old-timey radio, complete with Nixie tubes. The spinning part has blue and white LEDs, each accepting data from one of two serial ports. You can select to see data from one port, the other, or both. You can see the amazing contraption in the video below.
The LEDs are surface mounted and placed inside a glass test tube. Each display has its own processor. The project appears to have a PCB, but it is just a piece of fiberglass with a color print on top of it and holes drilled with a rotary tool. The board has no actual conductors — everything is point-to-point wiring. The base of the unit is old cookware. The slip ring is pretty interesting, too. It uses an old video tape head, D-cell batteries cut up, and contacts from a relay.
You might remember [Daniel] from his steampunk Victorian computer project, including a punk teletype and a magic eye tube. If you want some theory on these kinds of displays, we can help. If you just want a simple display, it doesn’t have to cost much.
Continue reading “Dual Channel POV Display Also Has Nixie Tubes”