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Hackaday Links: November 12, 2023

Somebody must really have it in for Cruise, because the bad press just keeps piling up for the robo-taxi company. We’ve highlighted many of the company’s woes in this space, from unscheduled rendezvous with various vehicles to random acts of vandalism and stupid AI pranks. The hits kept coming as California regulators pulled the plug on testing, which finally convinced parent company General Motors to put a halt to the whole Cruise testing program nationwide. You’d think that would be enough, but no — now we learn that Cruise cars had a problem recognizing children, to the point that there was concern that one of their autonomous cars could clobber a kid under the right conditions. The fact that they apparently knew this and kept sending cars out for IRL testing is a pretty bad look, to say the least. Sadly but predictably, Cruise has announced layoffs, starting with the employees who supported the now-mothballed robo-taxi fleet, including those who had the unenviable job of cleaning the cars after, err, being enjoyed by customers. It seems a bit wrongheaded to sack people who had no hand in engineering the cars, but then again, there seems to be a lot of wrongheadedness to go around.

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Homebrew Tire Inflator Pushes The Limits Of PVC Construction

Let’s just clear something up right from the start with this one: there’s literally no reason to build your own tire inflator from scratch, especially when you can buy a perfectly serviceable one for not a lot of money. But that’s missing the point of this build entirely, and thinking that way risks passing up yet another fascinating build from PVC virtuoso [Vang Hà], which would be a shame

The chances are most of you will recall [Vang Hà]’s super-detailed working PVC model excavator, and while we’re tempted to say this simple air pump is a step toward more practical PVC builds, the fact remains that the excavator was a working model with a completely homebrew hydraulic system. As usual, PVC is the favored material, with sheet stock harvested from sections of flattened pipe. Only the simplest of tools are used, with a hand drill standing in for a lathe to make such precision components as the compressor piston. There are some great ideas here, like using Schrader tire valves as the intake and exhaust valves on the pump cylinder. And that’s not to mention the assembly tips, like making a hermetic seal between the metal valves and the PVC manifold by reaming out a hole with a heated drill bit.

We’re not sure how much abuse a plastic compressor like this will stand up to, but then again, we’ve seen some commercially available tire inflators with far, far less robust internals than this one.

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Where Pollution Hits The Road: The Growing Environmental Hazard Of Rubber Tires

As ubiquitous as rubber tires are due to the many practical benefits they offer to cars, trucks, and other conveyances, they do come with a limited lifespan. Over time, the part of the tire that contacts the road surface wears away, until a tire replacement is necessitated. Perhaps unsurprisingly, the material that wears away does not magically vanish, but ends up in the environment.

Because of the materials used to create tires, this worn away material is counted as a microplastic, which is a known environmental pollutant. In addition, more recently it’s been found that one additive commonly found in tires, called 6PPD, is highly toxic to certain species of fish and other marine life.

There are also indications that these fine bits of worn-off tire contribute to PM2.5 particulate matter. This size of particulates is fine enough to penetrate deep into the lungs of humans and other animals, where they can cause health issues and exacerbate COPD and similar conditions. These discoveries raise a lot of questions about our use of tires, along with the question of whether electric vehicles stand to make this issue even worse.

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DIY Airless Tires Work Surprisingly Well

Airless tires have been “a few years away” from production for decades now. They’re one of the automotive version of vaporware (at least those meant for passenger vehicles), always on the cusp of being produced but somehow never materializing. They have a number of perks over traditional air-filled tires in that they are immune to flats and punctures, and since there aren’t any airless tires available at the local tire shop, [Driven Media] decided to make and test their own.

The tires are surprisingly inexpensive to make. A few pieces of drainage tubing of varying diameters, cut to short lengths, and then bolted together with off-the-shelf hardware is all it takes, although they note that there was a tremendous amount of hardware needed to fasten all the pipe lengths together. With the structure in place they simply cut a tread off of a traditional tire and wrapped it around each of the four assemblies, then bolted them up to their Caterham street-legal race car for testing.

While the ride quality was notoriously (and unsurprisingly) rough and bumpy, the tires perform admirably under the circumstances and survive being driven fairly aggressively on a closed-circuit race course. For such a low price and simple parts list it’s shocking that a major tire manufacturer like Michelin hasn’t figured out how to successfully bring one to a light passenger car yet.

Thanks to [Itay] for the tip!

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Hackaday Prize 2022: Recycled Tire Table Is Where The Rubber Meets The Road

The problem with good inventions is that we usually end up with way too many of that particular widget lying around, which can cause all kinds of problems. Take the car tire, for instance. They were a great invention that helped spell the end of buggy whips and broken wagon wheels. But there are so many used-up tires about today that some people end up burning them in large piles, of all possible things.

Not [Vaibhav], who prefers to turn trash into utilitarian treasures. With little more than an old tire, some jute rope, and four plastic drink bottles, they made a sturdy, low-slung piece of furniture that could be used as a coffee table, a foot stool, or whatever life calls for.

Construction was fairly simple and involved stabilizing the hollow core with a round piece of cardboard glued to either side of the tire. Then came the jute rope and glue artistry, which hides any trace of the foundational materials. Finally, [Vaibhav] glued four plastic bottles to the bottom to act as legs. We think that steel cans would last longer and support more weight, but if plastic bottles are the only option, you could always fill them with dirt or sand.

No-Battery Pressure Sensors For Bike Tyres

Finding out you’ve got a flat tyres halfway into a long ride is a frustrating experience for a cyclist. Maintaining the

While the epoxy does a great job of sealing the PCB to the valve extension, the overmoulding process would likely be key to producing a product with shelf-quality fit and finish. This test run was done with 3D printed ABS moulds.

correct tyre pressures is key to a good ride, whether you’re stacking up the miles on the road or tackling tricky single track in the mountains. [CaptMcAllister] has put together a device that makes keeping an eye on your tyres easy.

The device consists of an ultra low power microcontroller from Texas Instruments, paired with a pressure sensor. Set up for Near Field Communication, or NFC, it’s designed to be powered by the smartphone that queries the microcontroller for a reading. We featured a prototype back in 2015 which required mounting the device within the inner tube of the tyre itself. However, this required invasive installation and the devices tended to wear out over time due to flex damaging the delicate copper coil antenna.

The new design consists of the same microcontroller hardware, but mounted in a modified valve extension that fits to the fill valve of the bicycle tyre. The PCB is directly epoxied on to the valve extension, ensuring air can’t leak out over time. The assembly is then overmoulded in an injection moulding process to provide further sealing and protection against the elements. This should help immensely in rough-and-tumble mountain biking applications.

The new device provides a simple screw-on solution for tire pressure monitoring that’s set and forget — no batteries required. [CaptMcAllister] is currently investigating options for a production run, and given the simple design, we imagine it couldn’t be too hard to rattle off a few hundred or thousand units. We could imagine it would also pair well with a microcontroller, NFC reader, and a display setup on the handlebars to give live readings where required. We look forward in earnest to seeing where this project goes next!

Road Pollution Doesn’t Just Come From Exhaust

Alumni from Innovation Design Engineering at Imperial College London and the Royal College of Art want to raise awareness of a road pollution source we rarely consider: tire wear. If you think about it, it is obvious. Our tires wear out, and that has to go somewhere, but what surprises us is how fast it happens. Single-use plastic is the most significant source of oceanic pollution, but tire microplastics are next on the naughty list. The team calls themselves The Tyre Collective, and they’re working on a device to collect tire particles at the source.

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