Transportation Hacks

1516 Articles

Rubber Tracked Bicycle Is Horribly Inefficient

June 29, 2023 by 31 Comments

Wheeled bikes are efficient machines, and most cycling speed and distance records are held by them. However, [The Q] has a taste for weirder creations that amuse perhaps more than they serve as viable transportation. His latest experiments revolve around tracked propulsion methods.

The build is a wheelless bike that relies on long thin tracks mounted to a mountain bike frame. The tracks carriers are fabricated using steel box section fitted with cogged rollers. The tracks themselves are made using a pair of bicycle chains joined with welded steel bars. They’re fitted with slices of rubber cut out of traditional bike tires for grip. The rear track is driven from the bike’s pedals, while the front is merely left to run freely.

By virtue of its wide, flat tracks, the bike actually stands up on its own. It’s capable of riding in a straight line at slow speed, albeit relatively noisily. Steering is limited by virtue of the flat tracks, which don’t operate well at an angle to the ground. Since the tracks only contact the ground at a point, too, the bike has very high ground pressure, which would make it likely to sink into anything less solid than asphalt.

The build is relatively similar to [The Q]’s previous efforts to build a supposedly square-wheeled bike. What we’d really love to see at this point is a tracked bicycle that actually made the best of the technology – by being both swift and capable of crossing soft, marshy terrain. Video after the break.

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Honda Headunit Reverse Engineering, And The Dismal State Of Infotainment Systems

June 27, 2023 by 47 Comments

These days the dozen or so ECUs in an average car are joined by an infotainment system of some type, which are typically a large touch screen on the dashboard (the headunit) and possibly a couple of auxiliary units for the rear seats. These infotainment systems run anything from QNX to (Yocto) Linux or more commonly these days some version of Android. As [Eric McDonald] discovered with his 2021 Honda Civic, its headunit runs an archaic Android dating back to roughly 2012.

While this offers intriguing options with gaining root access via decade-old exploits that the car manufacturer never fixed, as [Eric] notes, this is an advantage that anyone who can gain access to the car’s CAN buses via e.g. the headlights, a wireless access point, or even inject an exploit via ADB radio can use to their advantage. Essentially, these infotainment systems are massive attack surfaces with all of their wired and wireless interfaces, combined with outdated software that you as the vehicle owner are forbidden to meddle with by the manufacturer.

Naturally taking this ‘no’ as a challenge as any civilized citizen would, [Eric] set out to not only root the glorified Android tablet that Honda seeks to pass off as a ‘modern infotainment system’, but also reverse-engineer the system as far as possible and documenting the findings on GitHub. As [Eric] also explains in a Hacker News discussion, his dream is to not only have documentation available for infotainment systems in general as a community effort, but also provide open source alternatives that can be inspected by security researchers rather than being expected to lean on the ‘trust me bro’ security practices of the average car manufacturer.

Although a big ask considering how secretive car manufacturers are, this would seem to be an issue that we should tackle sooner rather than later, as more and more older cars turn into driving security exploits just waiting to happen.

Luxury Train Cars Used To Ride On Paper Wheels

June 27, 2023 by 20 Comments

Early on, railways primarily used wheels made of wood or iron. The former were cheap and relatively easy to manufacture, while the latter had far superior wear qualities. It may surprise you to learn, however, that some railways once used wheels made out of paper, as [Train of Thought] explains.

The wheels were pioneered by a man known as Richard N. Allen, in the 19th century. The wheels were constructed by layering up hundreds of sheets of paper with glue, compacting them with a press, and allowing them to cure for a few weeks. The solid paper disks were then machined to size, and were drilled to accept bolts that attached metal plates for protection. The wheels were given a cast-iron hub and a steel rim for wear reasons.

The benefit of the wheels was that their composite paper construction helped damp vibrations and noise from the wheels and rails. The North American Pullman railway ended up using the wheels for sleeper and dining carriages for the more luxurious ride they provided.

The paper wheels were short lived, however. While the wheels were up to the task when new, they would fail much sooner than solid metal wheels. A series of derailments led to the wheels being declared unsafe for use in the US by 1915.

The wheels serve as a good example of wheels and tires acting as a tuned part of a whole suspension system. Experimental wheel designs come and go, but there are reasons why we landed on certain designs for certain applications, after all. Video after the break.

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An Android Phone Powers A Self Driving Car

June 27, 2023 by 31 Comments

As auto manufacturers have brought self-driving features to their products, we’re told about how impressive their technologies are and just how much computing power is on board to make it happen. Thus it surprised us (and it might also surprise you too) that some level of self-driving can be performed by an Android phone. [Mankaran Singh] has the full details.

It starts with the realization that a modern smartphone contains the necessary sensors to  perform basic self-driving, and then moves on to making a version of openpilot that can run on more than the few supported phones. It’s not the driver-less car of science fiction but one which performs what we think is SAE level 2 self driving, which is cruise control, lane centering, and collision warning. They take it out on the road in a little Suzuki on a busy Indian dual carriageway in the rain, and while we perhaps place more trust in meat-based driving, it does seem to perform fairly well

Self driving features are codified into a set of levels for an easy reference on what each is capable of doing. We’ve taken a look at it in the past, should you be interested.

Flying Submarine Documentary Is A Story Of Defied Assumptions

June 25, 2023 by 39 Comments

Donald Reid had a passion for applying himself to challenging problems, and in many ways his life’s work was that of developing a prototype submersible aircraft — or flying submarine — for which his son Bruce was a test pilot. [Jesse Moody] brought to our attention a fantastic documentary he created (with a short teaser trailer here) in which he interviews Bruce, and in the process teaches us all about a story that spanned decades and formed an important part of aviation history. Bruce experienced his share of hair-raising moments while testing the craft, but still has all of his fingers and limbs. Still, in his own words, “you wouldn’t be doing that kind of testing today!”

In many ways, the story revolves around defying assumptions. Without context, a “flying submarine” project might sound like a lone kook’s obsession, but Donald Reid was nothing of the sort. He was a brilliant engineer who was able solve problems by applying his skill and intellect with a laser-like focus. And it turns out that getting a submerged vehicle to successfully transition from waterbound craft to airborne is a source of numerous and novel problems that were not trivial to solve. In fact, these problems needed to be solved in order to develop the Tomahawk cruise missile, which is launched by submarine. And that brings us to the lawsuit that bookended it all.

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Will The Lilium Jet Work? A Deep-Dive Into The Physics Behind EVTOL Aircraft

June 22, 2023 by 26 Comments

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.

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Is This The World’s Largest Dot Matrix Printer?

June 22, 2023 by 27 Comments

[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.

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