Fail Of The Week: The Metal Hot End Upgrade

My son, Patrick, has observed on more than one occasion that I do not like 3D printing. That may sound odd, because I built a printer back in 2012 and since then I’ve built a lot of printers and I currently have at least three in my lab. But Patrick correctly realized that I don’t actually enjoy printing things that I need. What I do enjoy is building, fixing and even more importantly improving the printers themselves. If you are reading Hackaday, you probably know how that is. This is the story of an upgrade gone bad, although the ending is happy enough. If you’ve ever thought about moving from a traditional hot end to an all-metal hot end, you might want to hear me out and maybe I can save you some trouble.

A few years ago, I picked up an Anet A8 for a really low price. As printers go, it is adequate. Not bad, but not amazing. But it is a fun printer because you really need to do some work on it to brace the acrylic frame and fix other shortcomings. I merrily improved the printer quite a bit over a relatively short period of time and I also bought a bunch of aluminum extrusion to rebuild the frame to the AM8 plans you can find on Thingiverse.

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New Video Series: Raspberry Pi Pico And RP2040 Deep Dive With Uri Shaked

In case you’ve been living under a rock that doesn’t have internet access, the Raspberry Pi Foundation got into the silicon sales and microcontroller game all at once this year with the Raspberry Pi Pico. It’s small, it’s capable, and it costs a measly $4. Surely you have one or two of them by now, right? But how much do you know about what it can do?

Or maybe you don’t have one yet, but it’s on your list. In either case, you can get started learning about them right away because [Uri Shaked]’s Raspberry Pi Pico and RP2040 Deep Dive course has recently been freed from the hallowed halls of HackadayU. He even built an emulator to go with it. [Uri] is a great instructor, and we’re sure that goes double if you ever need a salsa dance teacher, which he has also mastered.

This class was held for five weeks beginning in May 2021, with each session being roughly an hour long. The only prerequisite is a basic understanding of bitwise math, but there are resources for that on the class IO page linked above.

Each class is incredibly well-organized and informative. In the first class, [Uri] begins building a living document that includes the class agenda, links to all resources used and mentioned, code examples, and assembly instructions where applicable. It’s basically a syllabus plus a whole lot more. [Uri] also spends a lot of time in the incredibly thorough 649-page data sheet for the RP2040, and a little bit of time in the much shorter Getting Started guide. If you think the data sheet is inaccessible, you’ll likely change your tune by the end of the first class after you’ve seen [Uri] use and peruse it.

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Know Audio: Amplifiers And Distortion

As we’ve traced our no-nonsense path through the world of Hi-Fi audio, we’ve started with the listener, understood the limitations of the human ear, and thence proceeded to the loudspeaker. We’ve learned a bit about speaker cabinets and their design, so it’s time to venture further down the chain to the amplifier that drives those speakers.

The sharp-eyed will be ready to point out that along this path also lies the  speaker cables, but since we’ll be looking at interconnects at a later date we’ll be making the dubious and simplistic assumption for now that the wires between speaker and amplifier are ideal conductors that don’t have a bearing on listening quality. We’ll be looking at amplifiers in enough detail to warrant more than one piece on the subject, so today we’ll start by considering in a slightly abstract way what an amplifier does and where it can fall short in its task. We’ll be introducing probably the most important thing to consider in any audio system, namely distortion.

The job of an audio amplifier is to take an audio signal at its input and present the same signal on its output at a greater amplitude. In the case of a preamplifier it will usually be designed to work with high impedances in the order of 50 kΩ at both input and output, while in a power amplifier designed to drive speakers or headphones it will drive a much lower impedance. Commonly this will be 4 Ω or 8 Ω for loudspeakers, and 32 Ω for headphones. Continue reading “Know Audio: Amplifiers And Distortion”

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

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”

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Mad Model M

Hand-Wired Hell Help

Do you dream of building a curvy ergonomic keyboard or macro pad, even though the idea of hand wiring gives you nightmares? You can make it a bit less troublesome with a tiny PCB for each key switch, as long as you have a reflow oven or you’re okay with a bit of surface-mount soldering for the diode, LED, and capacitor.

As a bonus, these should make switches a bit more secure against movement, and you could probably even get away with using hot swap sockets if you wanted. [Pedro Barbero] has the Gerber files available if you want to get some fabbed. We sort of wish we had used these on our dactyl, though the case is awfully tight and they might not fit.

Ultra-Mechanical Keyboard Angles with Lifter Motors

Lots of people prefer an angled keyboard, but plenty of new keebs, especially mechanical ones, just don’t offer that at all. Well, the wait for an adjustable 75% is over, at least. Okay, that’s not exactly true. The wait for a group buy to begin for an adjustable 75% is almost over.

Nestled in between the arrow cluster and the menu key of the Besides Studios M-One is a rocker switch that angles the keyboard from 3° to 7° slowly but surely, like an adjustable bed. This is going to be a bare-bones group buy, meaning that it won’t come with any switches, stabs, or keycaps, but that doesn’t mean it will be cheap at $299. [BadSeed Tech] got an early prototype and built it out with Gateron Ink Black V2 switches in the video below in order to give it a proper spin.

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Linux Fu: Superpowers For Mere Mortals

You can hardly mention the sudo command without recalling the hilarious XKCD strip about making sandwiches. It does seem like sudo is the magic power to make a Linux system do what you want. The only problem is that those superpowers are not something to be taken lightly.

CC-BY-NC-2.5 by [XKCD]
If you are surfing the web, for example, you really don’t want to be root, because if someone naughty takes over your computer they could do a lot more harm with your root password. But still, there are times when you want to run certain commands that are normally root-only and don’t want to bother with a password. Luckily, sudo can handle that use case very easily.

Why?

As a simple example, suppose you like to shut your computer down at the end of the day. You run the shutdown command from the terminal but it doesn’t work because you aren’t root. You then have to do it again with sudo and if you haven’t logged in lately, provide your password. Ugh.

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Hackaday Links: July 25, 2021

Everyone makes mistakes in their job, but very few of us get the chance to make a one-character mistake with the potential to brick millions of devices. But that’s what happened to a hapless Google developer, who made an understandable typo in the ChromeOS code that ended up making it all the way to production. The error, which was in the OS encryption keys vault, was supposed to include the “&&” operator for a logical AND. The developer instead used a single ampersand, which broke the who conditional statement. This meant the OS evaluated even correct passwords as invalid, leaving users locked out of their Chromebooks. To be fair to the developer there should be a lot of QA steps between that typo and production, but it still has to sting.

Speaking of whoopsies, sometimes it just doesn’t pay to be right on the internet. It started when a player of the popular tank battle simulator “War Thunder” took issue with the in-game 3D model of the British Challenger 2 main battle tank. The player argued that the model was inaccurate to the point of affecting gameplay, and thought the model should be changed to make things more realistic. There seemed to be some basis for this, as the player claimed to have been a Challenger 2 commander and gunnery instructor. What’s more, like any good Netizen, the player cited sources to back up the claims, including excerpts from the official Challenger 2 instruction manual. Players on the War Thunder forum flagged this as likely classified material, but the player insisted that it wasn’t — right up to the point where the UK Ministry of Defence said, “Not so fast.” It turns out that the manual hasn’t been declassified, and that releasing the material potentially runs afoul of the Official Secrets Act, which carries with it up to 14 years detention at Her Majesty’s pleasure.

For fans of pinball, the announcement that the Museum of Pinball in Banning, California is closing its doors for good is probably a mix of good news and bad. It’s obviously bad news for any museum to close, especially one that curates collections from popular culture. And there’s no denying that pinball has been a big part of that culture, and that the machines themselves are often works of electromechanical art. But it appears that the museum just couldn’t make a go of it, and now its cavernous space will be sold off to a cannabis grower. But the sad news is tempered by the potential for private collectors and other pinball aficionados to score one of the estimated 1,100 pins the museum now needs to find a home for. We’ve never been to the museum, so it’s hard to say what kinds of machines they have and how collectible they are, but regardless, the market is about to be flooded. If you’re nearby, you might want to take a chance to see and play some of these machines one last time, before they get shipped off to private game rooms around the world.

And finally, exciting news from Hackaday superfriend Fran Blanche, who will soon tick an item off her bucket list with a zero-G ride on “G-Force 1”. Not to be confused with its military cousin the “Vomit Comet”, the weightlessness-simulating aircraft will afford Fran a total of about five minutes of free-fall when she takes the ride in a couple of months. There will also be periods of the flight that will simulate the gravity on both the Moon and Mars, so Fran has promised some Matt Damon mythbusting and Buzz Aldrin moonbouncing. And always one to share, Fran will bring along a professional video crew, so she can concentrate on the experience rather than filming it. We’ve actually scheduled Fran for a Hack Chat in August, to talk about the flight and some of her other cool goings-on, so watch out for that.