Car Driving Simulators For Students, Or: When Simulators Make Sense

February 21, 2024 by Maya Posch 69 Comments

There are many benefits to learning to fly an airplane, drive a racing car, or operate some complex piece of machinery. Ideally, you’d do so in a perfectly safe environment, even when the instructor decides to flip on a number of disaster options and you find your method of transportation careening towards the ground, or the refinery column you’re monitoring indicating that it’s mere seconds away from going critical and wiping out itself and half the refinery with it.

Still, we send inexperienced drivers in cars onto the roads each day as they either work towards getting their driving license, or have passed their driving exam and are working towards gaining experience. It is this inexperience with dangerous situations and tendency to underestimate them which is among the primary factors why new teenage drivers are much more likely to end up in crashes, with the 16-19 age group having a fatal crash nearly three times as high as drivers aged 20 and up.

After an initial surge in car driving simulators being used for students during the 1950s and 1960s, it now appears that we might see them return in a modern format.

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3D Print Train Wheels For Garden Railway

February 18, 2024 by Jenny List 15 Comments

There’s something magical about a train, whether you call it a railway or a railroad, plenty of us have hankered after our own little piece of line on which to shunt wagons or chuff around our domain. Envy [Otis Rowell] then, because he’s made himself a garden railway with the laudable purpose of moving wood pellets for his heating. A mere garden railway may be cool but it’s not in itself special, so the reason we’re featuring it here comes from something else. He’s making his rail wheels by 3D printing them with a normal printer.

It’s important to understand that these wheels are not for a high-speed mainline express freight train but for a small flat car designed to carry a modest tub of pellets, thus they are less in need of high strength than their full-size cousins. But even a small car on garden railway-sized aluminum rails can exert significant force, so we would be fascinated to see how well these do. The write-up is a work in progress as this article is being written so we know there’s more to come, but there’s no harm in speculating as to how a better 3D-printed wheel might be made. We would be particularly curious for example as to whether a novel slicing regime could be used to make a stronger wheel.

If backyard railways interest you, it’s not the first time we’ve seen one.

AI-Powered Bumper Sticker Provides Context-Sensitive Urban Camouflage

February 14, 2024 by Dan Maloney 17 Comments

While we absolutely support the right of everyone to express their opinions, it seems to us that it’s rarely wise to turn your vehicle into a mobile billboard for your positions. Aside from potentially messing up the finish on your car, what’s popular and acceptable at home might attract unwanted attention while traveling abroad, leading to confrontations that might make your trip a little more eventful than it needs to be.

So why not let technology help you speak your mind in a locally sensitive manner? That’s the idea behind [Pegor]’s “smahtSticker”, an AI-powered bumper sticker that provides the ultimate in context-sensitive urban camouflage. The business end of smahtSticker — we’re going to go out on a limb here and predict that [Pegor] hails from the Boston area — is an 8.8″ (22-cm) wide HDMI display capable of 1920×480 resolution. That goes on the back of your car and is driven by a Raspberry Pi Zero with a GPS module. The Pi grabs a geolocation every second, and if you’ve moved more than 25 feet (7.6 m) — political divisions are at least that granular in the US right now, trust us — it grabs your current ZIP code using GeoPy. That initiates a query to the OpenAI API to determine the current political attitudes in your location, which is used to select the right slogan to display. You’ll fit in no matter where you wander — wicked smaht!

Now, of course, this is all in good fun, and with tongue planted firmly in cheek. The display isn’t weatherized at all, so that would need to be addressed if one felt like fielding this. Also, ZIP codes may be good for a lot of things, but it’s not the best proxy for political alignment, so you might want to touch that part up.

Bringing Modern Technology To A Sled

February 12, 2024 by Bryan Cockfield 17 Comments

Street sledding, a popular pastime in Norway, is an activity that is slowly dwindling in popularity, at least as far as [Justin] aka [Garage Avenger] has noticed. It used to be a fun way of getting around frozen lakes and roads during winter, and while some still have their sleds [Justin] wanted to see if there was a way to revitalize one of these sleds for the modern era. He’s equipped this one with powerful electric turbines than can quickly push the sled and a few passengers around the ice.

Since this particular sled is sized for child-sized passengers, fuel-burning jet engines have been omitted and replaced with electric motors that can spin their turbine blades at an impressive 80,000 rpm. The antique sled first needed to be refurbished, including removing the rust from the runners and reconditioning the wood. With a sturdy base ready to go, the sled gets a set of 3D printed cowlings for the turbines, a thumb throttle on the upgraded handlebars, and a big battery with an Arduino to bring it all together.

With everything assembled and a sheet of ice to try it out on, the powerful sled easily gets its passengers up to the 20-30 kph range depending on passenger weight and size. There’s a brake built on an old ice skate for emergency stops, and the sled was a huge hit for everyone at the skating pond. There are plenty of other ways to spruce up old sleds, too, like this one which adds a suspension for rocketing down unplowed roads.

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How Airplanes Mostly Stopped Flying Into Terrain And Other Safety Improvements

February 8, 2024 by Maya Posch 13 Comments

We have all heard the statistics on how safe air travel is, with more people dying and getting injured on their way to and from the airport than while traveling by airplane. Things weren’t always this way, of course. Throughout the early days of commercial air travel and well into the 1980s there were many crashes that served as harsh lessons on basic air safety. The most tragic ones are probably those with a human cause, whether it was due to improper maintenance or pilot error, as we generally assume that we have a human element in the chain of events explicitly to prevent tragedies like these.

Among the worst pilot errors we find the phenomenon of controlled flight into terrain (CFIT), which usually sees the pilot losing track of his bearings due to a variety of reasons before a usually high-speed and fatal crash. When it comes to keeping airplanes off the ground until they’re at their destination, here ground proximity warning systems (GPWS) and successors have added a layer of safety, along with stall warnings and other automatic warning signals provided by the avionics.

With the recent passing of C. Donald Bateman – who has been credited with designing the GPWS – it seems like a good time to appreciate the technology that makes flying into the relatively safe experience that it is today.

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Sailing (Directly) Into The Wind

February 6, 2024 by Bryan Cockfield 22 Comments

Humans have been sailing various seas and oceans for thousands of years, and using boats for potentially even longer than that. But as a species we wouldn’t have made it very far if it was only possible to sail in the same direction the wind is blowing. There are a number of methods for sailing upwind, but generally only up to a certain angle. [rctestflight] wondered if there was some way of sailing straight upwind instead and built this rotary sail craft to test the idea.

Normally a boat sailing upwind will sail approximately 45° into it, then “tack” 90° across the wind until they’re at another 45° angle from the wind, this time facing the opposite direction. This back-and-forth nature is not the most efficient path, so this vessel uses a few propellers to bypass the traditional sail. The first iteration, built on a sleek catamaran hull, uses a large propeller to catch the wind’s energy, then transfers it mechanically through a set of shafts to an underwater prop.

It took a few tries to get the size and pitch of both propellers narrowed down to where the boat would move forward into the wind, but move it does. A second major iteration of the build uses a single shaft with no gears, with the trade-off that neither propeller is facing an ideal direction, but this has the added benefit of the boat naturally pointing itself upwind.

While none of the designs are speed demons, the concept is sound enough. It’s just that, in most cases, performing multiple tacks to get upwind is acceptable compared to the extreme efficiency losses and drag from propeller-driven sailing crafts like these. A more effective way of propelling a boat upwind, at least using modern technology, might be to trade sails for solar panels.

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Transforming EDF Backpack For A Speed Boost

February 3, 2024 by Danie Conradie 18 Comments

Fighting against a tough headwind on your daily cycle can be a drag, but [Emiel] of The Practical Engineer, has a loud and bold solution. In the Dutch video after the break, he builds a transforming backpack with two electric ducted fans (EDFs), and takes to the bike paths.

An EDF moves a small volume of air at high velocity, which doesn’t make them great for low speed applications. But they’re nice and compact, and safer than large propellers. [Emiel] didn’t skimp on the rest of the hardware, with the motors attached to metal 3D printed arms, mounted on a machined aluminum steel plate.

The arms were printed courtesy of a sponsor, and created via generative design in Fusion 360 to make them both light and strong. A pair of large servos swing the arms up, while smaller servos rotate the motors into the horizontal position. The arm servos are controlled by an Arduino, and activated by a simple toggle switch attached to the backpack’s shoulder strap. A wireless remote similar to that of an electric skateboard is used to control the EDFs.

Fitted in a [Emiel]’s old backpack, the result looks somewhat innocuous (if you don’t look too closely) until it unfolds its hidden power—twin jets ready to blast away any pesky headwinds with the push of a button. It’s a fun solution that is sure to attract attention, and a great excuse to create heavy duty mechanics.

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