Kritik sah

The age of steam is long gone, but there are few railfans who don’t have a soft spot for the old rolling kettles. So you’d best believe when [AeroKoi] talks about 3D printed train whistles , that’s steam whistles. Generally speaking, Diesels have horns. You would not expect printed plastic to hold up to live steam– but that’s why [AeroKoi] uses compressed air. Besides, it’s a lot easier to both justify and maintain an air compressor than a boiler in the shop. At least some hobbyists say it doesn’t make a huge difference with brass whistles, so it should be good enough for plastic. What’s interesting is that even with 120 PSI blasting through them, these multi-part prints held together and sounded amazing. [AeroKoi] does demonstrate there was a learning curve to climb before he had a good whistle design, and shows you what features worked best. He shared two successes on Thingiverse: A 6-Chime whistle from the Sante Fe Railroad , and a N...

For this challenge, we asked you to show off your hacks that power themselves sustainably from the environment around them. After all, nobody likes wires, and changing batteries is just a hassle . What’s better than an autonomous gizmo? Nothing. Because this is Hackaday, we expected to see some finished-looking projects, some absolutely zany concepts, and basically everything in-between, and you did not disappoint! So without further ado, let’s have a look at the 2026 Green Powered Challenge winners, each of whom will be going on a $150 shopping spree at DigiKey, our contest’s sponsor. LightInk Solar Watch LightInk is a beautiful wristwatch , and e-ink is a natural companion to the small power budget that you get with a wrist-mounted solar panel. But don’t be fooled by its good looks! The real beauty of this hack is the way that [Daniel Ansorregui] crammed the screen-updating routine into the wakeup stub in the RTC peripheral. This means that the ESP32 doesn’t have to access the SP...

Presumably aimed at children, NHK World’s Texico program teaches the main ideas about programming without actually using a computer. Instead, it uses items like a toy train, playing cards, and other gadgets to teach concepts such as analysis, combination, simulation, abstraction, and more. There are ten episodes in English and French. Some of them are more about critical thinking, which, admittedly, is important for solving problems in general with or without a computer. For example, a “magic” trick relies on the observation that tearing a sheet of paper into nine rectangular pieces will mean each piece has at least one perfectly straight edge except for the center piece. The videos are short and light-hearted. We’d like to see a set of companion videos or posts that relate the lessons to some actual programming task. Of course, you could produce that yourself and host it on a platform like Hackaday.io or YouTube. The episodes show programming algorithms in ...

We’ve all done it. We spy an old radio at a garage sale or resale shop. We know someone should bring it back to life, but it looks like a project, so we pass it by. Not [Ken] from [Ken’s Shop]. He found an Arvin 664A AM radio from 1947 in what appears to be a home-built cabinet and decided to bring it back to life. From what we could find, the original case was a white plastic, not the wood box it is in today. So the first challenge was simply getting inside to see what was going on. Inside is a pretty standard lineup of six tubes and a few transformers. There were obvious signs that someone had already been in there, as there were some new capacitors grafted in. What follows is the kind of troubleshooting you have to do when you are working with an old, unloved radio. Getting it powered up was most of the battle and required replacing all the old capacitors. The radio actually sounded good once it was working. With the box cleaned up, a new speaker grille, and a new wi...

The idea of FDM 3D printing using granules rather than filament is an appealing one: rather than having to wrangle spools of filament that need to adhere to strict dimensions and cannot be too flexible, you can instead just keep topping up a big hopper with fresh granules. This is what [HomoFaciens] has been tinkering with for a while now, with their Direct Granules Extruder V7.0 showing significant improvements . There’s also an accompanying article , with details of previous granule extruder attempts detailed on the same site. Many of the improvements here focus on making sure the granules melt properly before they reach the end of the extruder, with the auger screw helping to push things along. While this seems straightforward, there are many details to get right, with the previous v6.2 version having issues like the hot plastic backing up into the cold section and clogging things up. For the test bench a Prusa Mk4 FDM printer is used, with the standard extruder swapped for t...

There are all manner of musical synthesis techniques, from the early electromechanical instruments through analogue tape systhesis, the all-electronic waveform synthesisers of the 1960s onwards, and Yamaha’s FM systhesis of the 1980s, to name but a few. One of the attributes of such a machine lies in how many voices it has, or in simple terms, how many notes it can play simultaneously. Electronic complexity limited those early synths, but what happens on an FPGA where vast numbers of circuits can be made with little extra cost? [Tsuneo.Ohnaka] is pushing the envelope a little, by cramming 10240 individually controllable oscillators onto a Terasic DE10-nano FPGA board . While this thing can in theory generate 10240 different notes at once, in practice that doesn’t mean it has 10240 voices. Instead he calls it a spectrum engine, in that with such a large number of oscillators all with individually controllable frequency, phase, and amplitude, he’s made the part of all t...