[Electronoobs] built a coil gun and the obvious question is: how fast is the projectile? To answer it, he built a chronograph suitable for timing a bullet. The principle is straightforward. A laser and a light sensor would mark the entry and exit of the projectile over a known distance. As it turns out, there are some issues to resolve.
For one thing, a laser is too narrow and might miss the projectile. The first attempt to rectify this used mirrors, but the loss was too great — we suspect he was using a second surface mirror. The final answer was to use an array of detectors and removed the laser’s collimation lens to cover a wider area.
[Alfredo Cortellini] was perusing an antique shop in Bologna, and came across a nice example of a late 1950s timepiece, in the shape of a Solari Cifra 5 slave clock, but as the shop owner warned, it could never tell the time by itself. That sounded like a challenge, and the resulting hack is a nice, respectful tweak of the internals to bring it into the modern era. Since the clock requires a single pulse-per-minute in order to track time, the simplest track often followed is to open the back, set the correct time manually by poking the appropriate levers, and then let an external circuit take over clocking it. [Alfredo] wanted autonomy, and came up with a solution to make the thing fully adjust itself automatically.
Electronics-wise, initial prototyping was performed with a Nucleo 32 dev board and a pile of modules, before moving to a custom PCB designed in Altium Designer. An STM32G031 runs the show, with a few push buttons and a SSD1306 OLED display forming the UI.
Using some strategically-placed magnets and hall effect sensors, the status of the internal mechanism could be determined. Minute advancements were effected by driving the clock’s 24V electromagnet with a DRV8871 motor driver IC, the power supply for which was generated from the USB supply via a TPS61041 boost converter. In order to synchronise the mechanism with the electronics, the unit could have been driven to advance a minute at a time, but since every hour would need sixty pulses, this could take a while given the limited speed at which that could be done reliably. The solution was to sneak in a crafty MG996R high-torque servo motor, which pushes on the hour-advancement lever, allowing the unit to be zeroed much faster. Sensing of the zero-hour position was done by monitoring the date-advance mechanism, that is not used in this model of clock. Once zeroed, the clock could then be advanced to the correct time and kept current. Firmware source, utililising FreeRTOS can be found on the project GItHub, with schematics and Fusion360 files on the Hackaday.IO project linked above.
If you were thinking you’ve seen these Solari soft-flap displays here before, you’d be quite correct, but if you’re not so much interested in marking the passage of time, but bending such devices to your other indication whims, we’ve got you covered also.
It may sound like a pop band, but μ-WAAM is actually a 3D printing technique for making small metal parts from the NOVA University Lisbon. Of course, WAAM stands for wire arc additive manufacturing, a well-known technique for 3D printing in metal. The difference? The new technique uses 250 μm wire stock instead of the 1mm or thicker wires used in conventional WAAM.
The thinner feed wire allows μ-WAAM to create fine details like thin walls that would be difficult to replicate with traditional methods. Typically, for fine structures, printers use fused metal powder. This is good for fine details, but typically slower and has higher waste than wire-based systems.
With 2022 off to a good start, it is about time to let go of all those New Year’s resolutions that didn’t quite work out. The scale’s needle didn’t reverse, our nails are still bitten, and we are still binge-watching Breaking Bad instead of reading the classics. But, of course, there’s always the future where we just know we’re going to stick to our resolutions. Besides, the future will be replete with fat-eating nanobots, 3D printed nails every morning, and a pill you can take that will make you remember reading Ulysses.
Predicting the future is fraught with peril, which is why launching a new company or product is so risky. However, there have been a few prognosticators that have made some impressive forecasts. For example, in 1922 popular (if not critically acclaimed) author W. L. George wrote a piece for The New York Herald titled “What the World Will be Like In a Hundred Years.” Since May will see that piece’s 100th anniversary, let’s see how he did.
It was just this year that Sega left the arcade business for good. A company synonymous with coin-op games for over a half century completely walked away from selling experiences you can only get on location. No more Outrun or Virtua Fighter machines, because arcades these days tend to resemble The House of the Dead. Arcades still exist to a degree, it’s just that headlines like that serve only as a reminder of an era gone by. Which is what makes raw footage like the video [Jon] posted of an Aladdin’s Castle arcade from the 1980s so compelling.
Aladdin’s Castle ad brochure circa 1983. Credit: John Andersen
The raw VHS footage starts with a sweep around the location’s pinball machines and arcade cabinets. There’s an extended shot of a rare TX-1 tri-monitor sitdown cabinet. The racing game was the first of its kind to feature force feedback in the steering wheel, so it’s no wonder it received the focus. The arcade’s lighting tech was also a point of pride as it allowed for programmable lighting cues. A far cry from the flickering fluorescent tubes no doubt in use elsewhere. Eventually the employee filming takes us to the back room where it the owner has made it abundantly clear that they are not a fan of Mondays, judging by the amount of Garfield merchandise.
Bally’s Aladdin’s Castle was a chain of arcades and had nearly 400 locations across the US at its height in the mid 1980s (at least according to their brochure seen above). Those neon red letters were a mainstay of American shopping malls throughout the decade. Namco, the Pac-Man people, acquired Aladdin’s Castle in 1993 and the brand faded away soon after. Although there is a lone location in Quincy, IL that is still open for business today.
Since NASA’s Mariner spacecraft made the first up-close observations of Mars in 1964, humanity has lobbed a long line of orbiters, landers, and rovers towards the Red Planet. Of course, it hasn’t all been smooth sailing. History, to say nothing of the planet’s surface, is littered with Martian missions that didn’t quite make the grade. But we’ve steadily been getting better, and have even started to push the envelope of what’s possible with interplanetary robotics through ambitious craft like the Ingenuity helicopter.
Yet, after nearly 60 years of studying our frigid neighbor, all we have to show for our work boils down to so many 1s and 0s. That’s not to say the data we’ve collected, both from orbit and on the surface, hasn’t been extremely valuable. But scientists on Earth could do more with a single Martian rock than any robotic rover could ever hope to accomplish. Even still, not so much as a grain of sand has ever been returned from the planet’s dusty surface.
But if everything goes according to plan, that’s about to change. Within the next decade, NASA and the European Space Agency (ESA) hope to bring the first samples of Martian rocks, soil, and atmospheric gases back to Earth using a series of robotic vehicles. While it’s still unclear when terrestrial scientists should expect delivery of this interplanetary bounty, the first stage of the program is already well underway. The Perseverance rover has started collecting samples and storing them in special tubes for their eventual trip back to Earth. By 2028, another rover will be deployed to collect these samples and load them into a miniature rocket for their trip to space.
Launching the Mars Ascent Vehicle (MAV).
Just last week NASA decided to award the nearly $200 million contract to build that rocket, known officially as the Mars Ascent Vehicle (MAV), to aerospace giant Lockheed Martin. The MAV will not only make history as the first rocket to lift off from a celestial body other than the Earth, but it’s arguably the most critical component of the sample return mission; as any failure during launch will mean the irrevocable loss of all the samples painstakingly recovered by Perseverance over the previous seven years.
To say this mission constitutes a considerable technical challenge would be an understatement. Not only has humanity never flown a rocket on another planet, but we’ve never even attempted it. No matter what the outcome, once the MAV points its nose to the sky and lights its engines, history is going to be made. But while it will be the first vehicle to make the attempt, engineers and scientists have been floating plans for a potential Martian sample return mission for decades. Continue reading “NASA Taps Lockheed To Bring Back A Piece Of Mars”→
If we’re being honest, the main reason to buy a power tool is to avoid the pain of using one’s muscles. Oh sure, we dress it up with claims that a power tool will make us more productive, or give better results, but more often than not it’s the memory of how your forearm feels after a day of twisting a screwdriver that makes you buy a cordless driver.
It appears that [Artisan Makes] has a high tolerance for pain, seeing how the main prep tool in his metal shop is a plain old hacksaw. So in an effort to speed up his stock prep, he turned not to a bandsaw or cutoff saw, but instead built the world’s silliest hacksaw. It’s the metalworking equivalent of the two-man bucksaws that lumberjacks used to fell trees before chainsaws came along, and at a meter and half in length, it’s about the size of one too. Modifying the frame of his trusty hacksaw was easy — he just popped the end pieces off and attached them to an extra-long piece of tube stock. Finding a 1.5-meter hacksaw blade was the main challenge; not exactly a big-box store item, that. So a section of metal-cutting bandsaw blade was modified to fit the frame, and it was off to the races.
Or not. The video below tells the tale of woe, which starts with the fact that [Artisan]’s shop is too small for the hilariously long hacksaw. Solving the fixturing problems didn’t soo much to help, though — there was no way to tension the blade enough to get it to stop wobbling during cutting. It was also clear that the huge saw wasn’t able to apply enough downforce on the stock to get good cuts. Maybe with a second set of hands, though…
There are plenty of ways to improve hacksawing in the shop, and while this isn’t one of them, we sure appreciate the chuckle we got out of it. And you really should check out [Artisan Makes]’ channel — his more serious stuff is really good.
