Better Mousetraps (or Screw Drives) Don’t Always Win

August 4, 2021 by 114 Comments

I’ve noticed, lately, that slotted screw heads are all but gone on new equipment. The only thing that I find remarkable about that is that it took so long. While it is true that slotted heads have been around for ages, better systems are both common and have been around for at least a century.

Check out those cool threads.

The reason slotted heads — technically known as the drive — are so common is probably because they are very easy to make. A hacksaw is sufficient for the job and there are other ways to get there, too. The only advantages I know of for the user is that you can easily clean a slotted drive and — possibly — use field expedient items like butter knives and quarters to turn the screw. I’ve heard people claim that it also is a feature that the screwdriver can pry things like paint can lids, but that’s a feature of the tool, not the screw drive.

The disadvantages, though, are significant. It is very hard to apply lots of torque to a slotted screw drive without camming it out or snapping the head off the screw. The screwdriver isn’t self-centering either, so applying force off-axis is common and contributes to the problem.

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[riskable]'s clacky magnetic switches

Mag-Lev Switches Are The Future Of Clacking

August 2, 2021 by 22 Comments

While there’s probably a Cherry MX clone born every year or so, it’s not often that such a radically different type of switch comes along. These “Void” switches are Hall-effect magnetic levitation numbers devised by keyboard connoisseur and designer [riskable]. Can you imagine how satisfying it is to clack on switches that actuate with magnets? They have adjustable tactility and travel thanks to even more tiny magnets. But you won’t be able to get these in a group buy or anything. If you want some of these babies, [riskable] says you’ll have to print and assemble ’em yourself.

These attractive switches don’t have a Cherry MX footprint, either, so you’ll need some of [riskable]’s AKUs, or Analog Keyboard Units (YouTube) to actually use them. [riskable] predicts that unlike the switches, the AKUs will likely be available to buy at some point in the future. (Okay good, because we really would love to know what these feel like in a keyboard!)

So, how do they work? As explained in the first video embedded below, there is one magnet in the slider and another in the housing. These two are attracted to each other, so actuating the switch separates them, which is where the Hall effect comes in. A third magnet in the keycap acts as the levitator to help return the switch to open position. The tactility of these switches is determined by the thickness of the plastic between the two lovebird magnets, so you could totally dial that in to whatever you want, in addition to all the other customization that 3D printing affords.

Tour and Teardown

The inimitable [Chyrosran22] featured these mag-nificent switches in one of his teardown videos, which is embedded below. One of the things [riskable] sent was a tactility sampler that ranges from an unimaginably tactile 0.0 mm of plastic in between them to not quite 2 mm.

In case you’re wondering, the video is remarkably safe-for-work, which is surprising given the content creator’s propensity for long strings of creative and hyphenated curses. We suppose [Chyrosran22] saves that stuff for the bad keyboards, then.

Stick around after the rightfully glowing review for [riskable]’s tour of a hand-wired analog macro pad using these switches. When you have a few extra minutes, check out the video build journey of these switches on [riskable]’s YouTube channel.

So, would these switches make the clickiest keyboard ever? Maybe, but consider this striking solenoid setup.

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Custom Instrument Cluster For Aging Car

August 1, 2021 by 32 Comments

All of the technological improvements to vehicles over the past few decades have led to cars and trucks that would seem borderline magical to anyone driving something like a Ford Pinto in the 1970s. Not only are cars much safer due to things like crumple zones, anti-lock brakes, air bags, and compulsory seat belt use, but there’s a wide array of sensors, user interfaces, and computers that also improve the driving experience. At least, until it starts wearing out. The electronic technology in our modern cars can be tricky to replace, but [Aravind] at least was able to replace part of the instrument cluster on his aging (yet still modern) Skoda and improve upon it in the process.

These cars have a recurring problem with the central part of the cluster that includes an LCD display. If replacement parts can even be found, they tend to cost a significant fraction of the value of the car, making them uneconomical for most. [Aravind] found that a 3.5″ color LCD that was already available fit perfectly in the space once the old screen was removed, so from there the next steps were to interface it to the car. These have a CAN bus separated from the main control CAN bus, and the port was easily accessible, so an Arduino with a RTC was obtained to handle the heavy lifting of interfacing with it.

Now, [Aravind] has a new LCD screen in the console that’s fully programmable and potentially longer-lasting than the factory LCD was. There’s also full documentation of the process on the project page as well, for anyone else with a Volkswagen-adjacent car from this era. Either way, it’s a much more economical approach to replacing the module than shelling out the enormous cost of OEM replacement parts. Of course, CAN bus hacks like these are often gateway projects to doing more involved CAN bus projects like turning an entire vehicle into a video game controller.

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Retrotechtacular: Understanding Protein Synthesis Through Interpretive Dance

August 1, 2021 by 8 Comments

With the principles of molecular biology very much in the zeitgeist these days, we thought it would be handy to provide some sort of visual aid to help our readers understand the complex molecular machines at work deep within each cell of the body. And despite appearances, this film using interpretive dance to explain protein synthesis will teach you everything you need to know.

Now, there are those who go on and on about the weirdness of the 1960s, but as this 1971 film from Stanford shows, the 60s were just a warm-up act for the really weird stuff. The film is a study in contrasts, with the setup being provided by the decidedly un-groovy Paul Berg, a professor of biochemistry who would share the 1980 Nobel Prize in Medicine for his contributions to nucleic acid research. His short sleeves and skinny tie stand in stark contrast to the writhing mass of students capering about on a grassy field, acting out the various macromolecules involved in protein synthesis. Two groups form the subunits of the ribosome, a chain of ballon-headed students act as the messenger RNA (mRNA) that codes for a protein, and little groups standing in for the transfer RNA (tRNA) molecules that carry the amino acids float in and out of the process.

The level of detail, at least as it was understood in 1971, is impressively complete, with soloists representing things like T-factor and the energy-carrying molecule GTP. And while we especially like the puff of smoke representing GTP’s energy transfer, we strongly suspect a lot of other smoke went into this production.

Kitsch aside, and with apologies to Lewis Carroll and his Jabberwock, you’ll be hard-pressed to find a modern animation that captures the process better. True, a more traditional animation might make the mechanistic aspects of translation clearer, but the mimsy gyre and gimble of this dance really emphasize the role random Brownian motion plays in macromolecular processes. And you’ll never see the term “tRNA” and not be able to think of this film.

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British Big Rigs Are About To Go Green

July 31, 2021 by 78 Comments

An increasing fact of life over the coming years will be the decarbonisation of our transport networks, for which a variety of competing solutions are being touted. Railways, trucks, cars, and planes will all be affected by this move away from fossil fuels, and while sectors such as passenger cars are making great strides towards electric drive, there remain some technical hurdles elsewhere such as with heavy road freight. To help inform the future of road transport policy in the UK then, the British government are financing a series of trials for transportation modes that don’t use internal combustion. These will include a battery-electric fleet for the National Health Service and a hydrogen-powered fleet in Scotland, as well as a trial of the same overhead-wire system previously given an outing in Germany, that will result in the electrification of a 12.4 mile section of the M180 motorway in Lincolnshire.

We’ve written about the overhead electrification project in Germany in the past and subjected it to a back-of-envelope calculation that suggested the total costs for a country such as the UK might be surprisingly affordable. The M180 is something of a backwater in the UK motorway network though, so it will be interesting to see how they approach the problem of finding real-world loads for their tests that ply such a short and isolated route. We’d expect the final picture to include all three technologies in some form, which can only be a good thing if it increases the available electric and hydrogen infrastructure. We’ll follow this story, though sadly we may not be able to blag a cab ride on the M180 in one of the trucks.

3D Printed Material Might Replace Kevlar

July 29, 2021 by 12 Comments

Prior to 1970, bulletproof vests were pretty iffy, with a history extending as far as the 1500s when there were attempts to make metal armor that was bulletproof. By the 20th century there was ballistic nylon, but it took kevlar to produce garments with real protection against projectile impact. Now a 3D printed nanomaterial might replace kevlar.

A group of scientists have published a paper that interconnected tetrakaidecahedrons made up of carbon struts that are arranged via two-photon lithography.

We know that tetrakaidecahedrons sound like a modern invention, but, in fact, they were proposed by Lord Kelvin in the 19th century as a shape that would allow things to be packed together with minimum surface area. Sometimes known as a Kelvin cell, the shape is used to model foam, among other things.

The 3D printing, in this case, is a form of lithography using precise lasers, so you probably won’t be making any of this on your Ender 3. However, the shape might have some other uses when applied to conventional 3D printing methods.

We’ve actually had an interest in the history of kevlar. Then again, kevlar isn’t the only game in town.

How To Modify Your Car Stereo For Bluetooth Or Aux-In

July 28, 2021 by 42 Comments

If you’re an automotive enthusiast of taste, you can’t stand the idea of fitting a janky aftermarket stereo into your nice, clean ride. Flashy, modern head units can spoil the look of a car’s interior, particularly if the car is a retro, classic, or vintage ride.

Thus, we’re going to look at how to modify your existing stock car stereo to accept an auxiliary cable input or even a Bluetooth module. This way, you can pump in the latest tunes from your smartphone without a fuss, while still maintaining an all-original look on the dash.

Fundamentals

A simple Bluetooth module designed for wiring into car audio systems. There are two wires for 12 V power from the vehicle, and the audio signal is sent out over the RCA plugs. The RCA plugs can be cut off and the module hard wired inside your stereo if you have room. Cutting off the plastic case can help too.

Depending on your choice of audio player, you may prefer a 3.5 mm aux jack, or you might want to go with Bluetooth audio if your smartphone no longer has a headphone port. Whichever way you go, the process of modifying the stereo is largely the same. To achieve your goal, you need to find a way of injecting the audio signal into the head unit’s amplifier stage, while making sure no other audio sources are getting sent there as well.

Whether that audio source is a 3.5 mm jack or a Bluetooth module doesn’t matter. The only difference is, in the latter case, you’ll want to buy a Bluetooth module and hardwire it in to the auxiliary input you create, while also splicing the module into the stereo’s power supply. In the case of a simple headphone jack input, you simply need to wire up an aux cord or 3.5 mm jack somewhere you can get to it, and call it done.

This guide won’t cover every stereo under the sun, of course. Edge cases exist and depending on the minute specifics of how your original car radio works, these exact methods may or may not work for you. However, this guide is intended to get you thinking conceptually about how such mods are done, so that you can investigate the hardware in front of you and make your own decisions about how to integrate an external audio input that suits your usage case. Continue reading “How To Modify Your Car Stereo For Bluetooth Or Aux-In” →