PLA Gears Fail To Fail In 3D Printed Bicycle Drivetrain

October 10, 2025 by Tyler August 30 Comments

Anyone who has ever snapped a chain or a crank knows how much torque a bicycle’s power train has to absorb on a daily basis; it’s really more than one might naively expect. For that reason, [Well Done Tips]’s idea of 3D printing a gear chain from PLA did not seem like the most promising of hacks to us.

Contrary to expectations, though, it actually worked; at the end of the video (at about 13:25), he’s on camera going 20 km/h, which while not speedy, is faster than we thought the fixed gearing would hold up. The gears themselves, as you can see, are simple spurs, and were modeled in Fusion360 using a handy auto-magical gear tool. The idler gears are held in place by a steel bar he welded to the frame, and are rolling on good old-fashioned skateboard bearings–two each. (Steel ones, not 3D printed bearings.) The healthy width of the spur gears probably goes a long way to explaining how this contraption is able to survive the test ride.

The drive gear at the wheel is steel-reinforced by part of the donor bike’s cassette, as [Well Done Tips] recognized that the shallow splines on the freewheel hub were not exactly an ideal fit for PLA. He does complain of a squeaking noise during the test ride, and we can’t help but wonder if switching to helical gears might help with that. That or perhaps a bit of lubricant, as he’s currently riding the gears dry. (Given that he, too, expected them to break the moment his foot hit the pedal, we can’t hardly blame him not wanting to bother with grease.)

We’ve seen studies suggesting PLA might not be the best choice of plastic for this application; if this wasn’t just a fun hack for a YouTube video, we’d expect nylon would be his best bet. Even then, it’d still be a hack, not a reliable form of transportation. Good thing this isn’t reliable-transportation-a-day!

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Possibly The Newest ISA Card

October 10, 2025 by Al Williams 13 Comments

Back when the IBM PC was new, laying out an ISA board was a daunting task. You probably didn’t have a very fast ‘scope, if you had one at all. Board layout was almost certainly done on a drafting table with big pieces of tape. It was hard for small companies, much less hobbyists, to make a new card. You could buy a prototype board and wirewrap or otherwise put together something, but that was also not for the faint of heart. But with modern tools, something like that is a very doable project and [profdc9] has, in fact, done it. The card uses an ATMega328P and provides two SD cards for use as mass storage on an old computer.

The design tries to use parts that won’t be hard to get in the future. At least for a while, yet. There’s capacity for expansion, too, as there is an interface for a Wiznet 5500 Ethernet adapter.

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A Function Generator From The Past

October 10, 2025 by Jenny List 9 Comments

It’s always a pleasure to find a hardware hacker who you haven’t seen before, and page back through their work. [Bettina Neumryr]’s niche comes in building projects from old electronics magazines, and her latest, a function generator from the British Everyday Electronics magazine in April 1983, is a typical build.

The project uses the XR2206 function generator chip, a favourite of the time. It contains a current controlled oscillator and waveform shaper, and can easily produce square, triangle, and sine waves. It was always a puzzle back in the day why this chip existed as surely the global market for function generators can’t have been that large, however a little bit of background reading for this write-up reveals that its intended application was for producing frequency-shift-keyed sinusoidal tones.

The two PCBs on the bench, with a multimeter — Yellow-stained boards for the win!

The EE project pairs the XR2206 with an op-amp current generator to control the frequency, and another op-amp as an amplifier and signal conditioner. The power supply is typical of the time too, a mains transformer, rectifier, and linear regulators. There are a pair of very period PCBs supplied as print-outs in the magazine for home etching. This she duly does, though with toner transfer which would have been unheard of in 1983. After a few issues with faulty pots and a miswired switch, she has a working function generator which she puts in a very period project box.

It’s interesting to look at this and muse on what’s changed in electronic construction at our level in the last four decades. The PCB is single sided and has that characteristic yellow of ferric chloride etching, it takes up several times the space achievable with the same parts on the professionally-made dual-sided board designed using a modern PCB CAD package we’d use today. A modern take on the same project would probably use a microcontroller and a DAC, and a small switch-mode supply for less money than that transformer would provide the power. But we like the 1983 approach, and we commend [Bettina] for taking it on. The full video is below the break.

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Hackaday Podcast Episode 341: Qualcomm Owns Arduino, Steppers Still Dominate 3D Printing, And Google Controls Your Apps

October 10, 2025 by Jenny List 1 Comment

The nights are drawing in for Europeans, and Elliot Williams is joined this week by Jenny List for an evening podcast looking at the past week in all things Hackaday. After reminding listeners of the upcoming Hackaday Supercon and Jawncon events, we take a moment to mark the sad passing of the prolific YouTuber, Robert Murray-Smith.

Before diving into the real hacks, there are a couple of more general news stories with an effect on our community. First, the takeover of Arduino by Qualcomm, and what its effect is likely to be. We try to speculate as to where the Arduino platform might go from here, and even whether it remains the player it once was, in 2025. Then there’s the decision by Google to restrict Android sideloading to only approved-developer APKs unless over ADB. It’s an assault on a user’s rights over their own hardware, as well as something of a blow to the open-source Android ecosystem. What will be our community’s response?

On more familiar territory we have custom LCDs, algorithmic art, and a discussion of non-stepper motors in 3D printing. Even the MakerBot Cupcake makes an appearance. Then there’s a tiny RV, new creative use of an ESP32 peripheral, and the DVD logo screensaver, in hardware. We end the show with a look at why logic circuits use the voltages they do. It’s a smorgasbord of hacks for your listening enjoyment.

Download yourself an MP3 even without a Hackaday Listeners’ License.

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QUIC! Jump To User Space!

October 10, 2025 by Al Williams 18 Comments

Everyone knows that Weird Al lampooned computers in a famous parody song (It’s All About the Pentiums). But if you want more hardcore (including more hardcore language, so if you are offended by rap music-style explicit lyrics, maybe don’t look this up), you probably want “Kill Dash 9” by Monzy. There’s a line in that song about “You thought the seven-layer model referred to a burrito.” In fact, it refers to how networking applications operate, and it is so ingrained that you don’t even hear about it much these days. But as [Codemia] points out, QUIC aims to disrupt the model, and for good reason.

Historically, your application (at layer 7) interacts with the network through other layers like the presentation layer and session layer. At layer 4, though, there is the transport layer where two names come into play: TCP and UDP. Generally, UDP is useful where you want to send data and you don’t expect the system to do much. Data might show up at its destination. Or not. Or it might show up multiple times. It might show up in the wrong order. TCP solves all that, but you have little control over how it does that.

When things are congested, there are different strategies TCP can use, but changing them can be difficult. That’s where QUIC comes in. It is like a user-space TCP layer built over a UDP transport. There are a lot of advantages to that, and if you want to know more, or even just want a good overview of network congestion control mitigations, check the post out.

If you want to know more about congestion control, catch a wave.

This Week In Security: ID Breaches, Code Smell, And Poetic Flows

October 10, 2025 by Jonathan Bennett 7 Comments

Discord had a data breach back on September 20th, via an outsourced support contractor. It seems it was a Zendesk instance that was accessed for 58 hours through a compromised contractor user account. There have been numbers thrown around from groups claiming to be behind the breach, like 1.6 Terabytes of data downloaded, 5.5 million user affected, and 2.1 million photos of IDs.

Discord has pushed back on those numbers, stating that it’s about 70,000 IDs that were leaked, with no comments on the other claims. To their credit, Discord has steadfastly refused to pay any ransom. There’s an interesting question here: why were Discord users’ government issued IDs on record with their accounts?

The answer is fairly simple: legal compliance. Governments around the world are beginning to require age verification from users. This often takes the form of a scan of valid ID, or even taking a picture of the user while holding the ID. There are many arguments about whether this is a good or bad development for the web, but it looks like ID age verification is going to be around for a while, and it’ll make data breaches more serious.

In similar news, Salesforce has announced that they won’t be paying any ransoms to the group behind the compromise of 39 different Salesforce customers. This campaign was performed by calling companies that use the Salesforce platform, and convincing the target to install a malicious app inside their Saleforce instance. Continue reading “This Week In Security: ID Breaches, Code Smell, And Poetic Flows” →

BenchVolt PD: USB PD Meets Benchtop Precision

October 10, 2025 by Matt Varian 39 Comments

USB power has become ubiquitous — everything from phones to laptops all use it — so why not your lab bench? This is what [EEEngineer4Ever] set out to do with the BenchVolt PD USB adjustable bench power supply. This is more than just a simple breakout for standard USB PD voltages, mind you; with adjustable voltages, SCPI support, and much more.

The case is made of laser-cut acrylic, mounted to an aluminum base, not only providing a weighted base but also helping with dissipating heat when pulling the 100 W this is capable of supplying. Inside the clear exterior, not only do you get to peek at all the circuitry but there is also a bright 1.9-inch TFT screen showing the voltage, current, and wattage of the various outputs. There is a knob that can adjust the variable voltage output and navigate through the menu. Control isn’t limited to the knob, mind you; there also is a Python desktop application to make it easy changing the settings and to open up the possibility to integrate its control alongside other automated test equipment.

There are five voltage outputs in this supply: three fixed ones—1.8 V, 2.5 V, and 3.3 V—and two adjustable ones: 0.5-5 V and 2.5-32 V. All five of these outputs are capable of up to 3 A. There are also a variety of waveforms that can be output, blurring the lines between power supply and function generator. While the BenchVolt PD will be open-sourced, [EEEngineer4Ever] will soon be releasing it over on CrowdSupply for those interested in one without building one themselves. We are big fans of USB PD gear, so be sure to check out some other USB PD projects we’ve featured.

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