Square-Wheeled Bike Is Actually An Amazing Tracked Build

The invention of the wheel is considered one of the crowning achievements of early humanity. Squares don’t roll, after all. [The Q] decided to build a square-wheeled bike anyway, with a neat tracked setup that makes for an awesome visual gag.

The wheels are made out of C-angle steel, making them both stout and incredibly heavy. While they don’t really need the additional structure for strength, they feature spokes which mount a central hub for attaching the “wheels” to a bicycle axle. The squares aren’t designed to roll, though. Instead, they are fitted with gears and rollers, upon which a track made of bicycle chain and tires is fitted. When the rider pedals, this turns the track, propelling the bike along. Cleverly, the track mechanism is neatly hidden by some framing, confusing passers-by.

The riding experience is noisy, thanks to the tracks. There’s also plenty of rolling resistance. It’s unlikely bikes like these will become mainstream transport anytime soon, nor will you see them at the velodrome. Regardless, it’s certainly a great way to turn heads at the park.

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Autopsy Of A Drifting Thumbstick Reveals All

Analog sticks have become a core part of modern video game controllers. They also routinely fail or end up drifting, consigning expensive controllers to the garbage. [sjm4306] recently did a repair job on an Oculus VR gaming controller with drifting analog sticks, and decided to do an autopsy to figure out what actually went wrong.

A microscope reveals gouges in the resistive material, caused by the metal contacts inside the analog stick. This happened via regular use.

The video starts by taking apart the analog joystick itself by prying off the metal case. Inside, we get a look at the many tiny individual components that make up a modern thumbstick. Of most interest, though, are the components that make up the potentiometers within the stick. Investigation revealed that the metal contacts that move with the stick had worn through the resistive coating on the thin plastic membrane in the base of the joystick, creating the frustrating drift problem.

It doesn’t have to be this way. Analog sticks in modern controllers could be manufactured with higher-quality components that don’t wear so easily. After all, it’s hard to imagine a 90s video game controller wearing out as fast as this modern Oculus unit. But everything is built to a price, at the end of the day, and that’s just how it goes. Video after the break.

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Weird 555 Function Generator Uses Feedback

There are plenty of designs out there for sawtooth and triangle function generators, many of them using the humble 555 IC. Few are readily voltage controlled, making them difficult to work with using a DAC, though. Enter this useful design posted to EDN!

The nifty design allows both waveshape and amplitude to be controlled via voltage. You could hook up a couple of  potentiometers and call it done. Or, even better, you can control these parameters via PWM output from a microcontroller. Handy, no? It’s achieved by a fancy routing that sends feedback from the 555’s output pin to the CV input, instead of the usual design that uses the THR and TRG pins instead. The design also allows the production of both symmetrical and asymmetrical triangle waveforms, and as a bonus, the whole oscillator draws less than 4 mW of power.

If you’re looking for a nifty triangle/sawtooth generator that sits neatly in your otherwise-digital design, this could be for you. Or, you might like to explore the sheer mountain of other 555 hacks we’ve featured over the years. We even held a contest! If you’ve got new 555 hacks the world needs to see, don’t hesitate to drop them into the tipsline.

 

If They Fire The Nukes, Will They Even Work?

2022 was a harrowing year in a long line of harrowing years. A brutal war in Europe raised the prospect of nuclear war as the leaders behind the invasion rattled sabers and made thinly veiled threats to use weapons of mass destruction. And all this as we’re still working our way through the fallout of a global pandemic.

Those hot-headed threats raise an interesting question, however. Decades have passed since either Russia or the United States ran a live nuclear weapons test. Given that, would the nukes even work if they were fired in anger?

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How Tattoos Interact With The Immune System Could Have Impacts For Vaccines

Tattoos are an interesting technology. They’re a way of marking patterns and designs on the skin that can last for years or decades. All this, despite the fact that our skin sloughs off on a regular basis!

As it turns out, tattoos actually have a deep and complex interaction with our immune system, which hold some of the secrets regarding their longevity. New research has unveiled more insight into how the body responds when we get inked up.

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The Liquid Trees Of Belgrade: The Facts Behind The Furore

Historically, nature has used trees to turn carbon dioxide back into oxygen for use by living creatures. The trees play a vital role in the carbon cycle, and have done so for millennia. Recently, humans have thrown things off a bit by getting rid of lots of trees and digging up a lot more carbon.

While great efforts are underway to replenish the world’s tree stocks, Belgrade has gone in a different direction, creating artificial “liquid trees” to capture carbon dioxide instead. This has spawned wild cries of dystopia and that the devices are an affront to nature. Let’s sidestep the hysteria and look at what’s actually going on.

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Largest Ever Hydrogen Fuel Cell Plane Takes Flight

In the automotive world, batteries are quickly becoming the energy source of the future. For heavier-duty tasks, though, they simply don’t cut the mustard. Their energy density, being a small fraction of that of liquid fuels, just can’t get the job done. In areas like these, hydrogen holds some promise as a cleaner fuel of the future.

Universal Hydrogen hopes that hydrogen will do for aviation what batteries can’t. The company has been developing flight-ready fuel cells for this exact purpose, and has begun test flights towards that very goal.

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