A tricked-out kids' Jeep in black and silver.

Driven To Over-Engineer A Kids’ Car

You know, it feels as though it’s getting more and more difficult to compete for Father of the Year around here. And [Jon Petter Skagmo] just laid down a new gauntlet — the incredibly overly-engineered kids car.

Close-up of the dash panel of an overly-engineered kids' car.While the original plan was to build the entire car from scratch, [Jon] eventually opted to use an off-the-shelf car that had a dead battery.

While the original architecture was quite simple, the new hardware has just about everything a kid could want in a tricked-out ride, most of which is accessible through the really cool dashboard.

We’re talking headlights, a music player, a siren, a selfie video cam that doubles as two-way communication with the driver, and even a garage door opener that uses an MQTT connection.

Under the cute little hood is where you’ll find most of the electronics. The car’s brain is a Raspberry Pi 3B, and there’s a custom daughter board that includes GPS/GNSS. This was originally meant to geofence [Baby Girl Skagmo] in, but Dad quickly realized that kids are gonna kid and disabled it pretty soon after.

This isn’t the first high-tech rebuild of a kiddie car that we’ve seen here at Hackaday. Makes us wish we were quite a bit smaller…

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Building A Small Gyro Stabilized Monorail

Monorails aren’t just the core reason why The Simpsons remains on air after thirty-six seasons, twenty-six of which are unredeemable garbage. They’re also an interesting example of oddball rail travel which has never really caught on beyond the odd gadgetbahn project here and there. [Hyperspace Pirate] recently decided to investigate the most interesting kind of monorail of all—the gyro stabilized type—on a small scale for our viewing pleasure.

The idea of a gyro-stabilized monorail is to use active stability systems to allow a train to balance on a single very thin rail. The benefits of this are questionable; one ends up with an incredibly expensive and complex rail vehicle that must always run perfectly or else it will tip over. However, it is charming to watch in action.

[Hyperspace Pirate] explains how the monorail vehicle uses control moment gyroscopes to keep itself upright. The video also explains the more common concept of reaction wheels so the two systems can be contrasted and compared. It all culminates in a wonderful practical demonstration with a small 3D printed version of a 20th-century gyro monorail running on a 24″ track.

If you’re studying mechanical engineering this is a great project to pore over to see theoretical principles put into obvious practice. Video after the break.

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Tech In Plain Sight: Speedometers

In a modern car, your speedometer might look analog, but it is almost certainly digital and driven by the computer that has to monitor all sorts of things anyway. But how did they work before your car was a rolling computer complex? The electronic speedometer has been around for well over a century and, when you think about it, qualifies as a technlogical marvel.

If you already know how they work, this isn’t a fair question. But if you don’t, think about this. Your dashboard has a cable running into it. The inner part of the cable spins at some rate, which is related to either the car’s transmission or a wheel sensor. How do you make a needle deflect based on the speed?

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Open Source Liquid Rocket Reaches For The Sky

Since the very beginning, solid-propellants have been the cornerstone of amateur rocketry. From the little Estes rocket picked up from the toy store, to vehicles like the University of Southern California’s Traveler IV that (probably) crossed the Kármán line in 2019, a rapidly burning chunk of solid propellant is responsible for pushing them skyward. That’s not to say that amateur rockets powered by liquid propellants are completely unheard of … it’s just that getting them right is so ridiculously difficult that comparatively few have been built.

But thanks to [Half Cat Rocketry], we may start to see more hobbyists and students taking on the challenge. Their Mojave Sphinx liquid-fueled rocket is not only designed to be as easy and cheap to build as possible, but it’s been released as open source so that others can replicate it. All of the 2D and 3D CAD files have been made available under the GPLv3 license, and if you’re in the mood for a little light reading, there’s a nearly 370 page guidebook you can download that covers building and launching the rocket.

Now of course we’re still talking about literal rocket science here, so while we don’t doubt a sufficiently motivated individual could put one of these together on their own, you’ll probably want to gather up a couple friends and have a well-stocked makerspace to operate out of. All told, [Half Cat] estimates you should be able to build a Mojave Sphinx for less than $2,000 USD, but that assumes everything is done in-house and you don’t contract out any of the machining.

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For years, the first Air Force One sat neglected and forgotten in an open field at Arizona’s Marana Regional Airport. (Credit: Dynamic Aviation)

The First Air Force One And How It Was Nearly Lost Forever

Although the designation ‘Air Force One’ is now commonly known to refer to the airplane used by the President of the United States, it wasn’t until Eisenhower that the US President would make significant use of a dedicated airplane. He would have a Lockheed VC-121A kitted out to act as his office as commander-in-chief. Called the Columbine II after the Colorado columbine flower, it served a crucial role during the Korean War and would result the coining of the ‘Air Force One’ designation following a near-disaster in 1954.

This involved a mix-up between Eastern Air Lines 8610 and Air Force 8610 (the VC-121A). After the Columbine II was replaced with a VC-121E model (Columbine III), the Columbine II was mistakenly sold to a private owner, and got pretty close to being scrapped.

In 2016, the plane made a “somewhat scary and extremely precarious” 2,000-plus-mile journey to Bridgewater, Virginia, to undergo a complete restoration. (Credit: Dynamic Aviation)
In 2016, the plane made a “somewhat scary and extremely precarious” 2,000-plus-mile journey to Bridgewater, Virginia, to undergo a complete restoration. (Credit: Dynamic Aviation)

Although nobody is really sure how this mistake happened, it resulted in the private owner stripping the airplane for parts to keep other Lockheed C-121s and compatible airplanes flying. Shortly before scrapping the airplane, he received a call from the Smithsonian Institution, informing him that this particular airplane was Eisenhower’s first presidential airplane and the first ever Air Force One. This led to him instead fixing up the airplane and trying to sell it off. Ultimately the CEO of the airplane maintenance company Dynamic Aviation, [Karl D. Stoltzfus] bought the partially restored airplane after it had spent another few years baking in the unrelenting sun.

Although in a sorry state at this point, [Stoltzfus] put a team led by mechanic [Brian Miklos] to work who got the airplane in a flying condition by 2016 after a year of work, so that they could fly the airplane over to Dynamic Aviation facilities for a complete restoration. At this point the ‘nuts and bolts’ restoration is mostly complete after a lot of improvisation and manufacturing of parts for the 80 year old airplane, with restoration of the Eisenhower-era interior and exterior now in progress. This should take another few years and another $12 million or so, but would result in a fully restored and flight-worthy Columbine II, exactly as it would have looked in 1953, plus a few modern-day safety upgrades.

Although [Stoltzfus] recently passed away unexpectedly before being able to see the final result, his legacy will live on in the restored airplane, which will after so many years be able to meet up again with the Columbine III, which is on display at the National Museum of the USAF.

500cc Of 4-Wheel Off-Road Fun

Who among us hasn’t at some point thought of building a little vehicle, and better still, a little off-road vehicle for a few high-octane rough-terrain adventures. [Made in Poland] has, and there he is in a new video with a little off-road buggy.

The video which we’ve paced below the break is quite long, and it’s one of those restful metalworking films in which we see the finished project take shape bit by bit. In this case the buggy has a tubular spaceframe, with front suspension taken from a scrap quad and a home-made solid rear axle. For power there’s a 500cc Suzuki two-cylinder motorcycle engine, with a very short chain drive from its gearbox to that axle. The controls are conventional up to a point, though we’d have probably gone for motorcycle style handlebars with a foot shift rather than the hand-grip shift.

The final machine is a pocket drift monster, and one we’d certainly like to have a play with. We’d prefer some roll-over protection and we wonder whether the handling might be improved were the engine sprung rather than being part of a huge swing-arm, but it doesn’t appear to interfere with the fun. If you fancy a go yourself it’s surprisingly affordable to make a small vehicle, just build a Hacky Racer.

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A map of the US showing the potential changes to passenger rail service due to the Corridor ID Program

A New Era For US Passenger Rail?

Here in the United States, we’re lagging behind the rest of the world when it comes to shiny new passenger rail, despite being leaders in previous centuries. The Federal Railroad Administration (FRA) has just released a story map of how the US could close the gap (a little).

A new blue and white high speed train crosses a brick bridge. There is what looks like a park beneath and a cityscape in the background.The Corridor Identification and Development (CID) Program is a way for FRA to provide both funding and technical assistance as corridor sponsors (mostly state Departments of Transportation) evaluate either new intercity service or expansion of existing services. While it isn’t a guarantee of anything, it is a step in the right direction to rebuilding passenger rail capacity in the US.

Some cities would be getting rail service back for the first time in decades, and perhaps even more exciting is that several of the routes being studied are for high speed rail “primarily or solely on new trackage.” As any railfan can tell you, vintage rails aren’t the best for trains going fast (sorry, Acela). With recent polling showing strong public support for the build out of high speed rail, it’s an exciting time for those who prefer to travel by rail.

We don’t think you’ll be able to ride a gyro monorail, nuclear-powered, or jet train on these proposed routes, but we do hope that Amtrak and FRA are looking to the state-of-the-art when it comes to those high speed alignments. While you’re eagerly awaiting new passenger service, might we recommend this field guide to what all those different freight cars going by are for here in North America?