Rolling Your Own Ball Screws

December 4, 2024 by 24 Comments

We’ve got mixed feelings about a new video from [AndysMachines] that details how he makes custom ball screws. On the one hand, there’s almost zero chance that we’ll ever have an opportunity to put this information to practical use. But on the other hand, the video gives a fantastic look at the inner workings and design considerations for ball screws, which is worth the price of admission alone

The story behind these ball screws is that [Andy] is apparently in cahoots with SkyNet and is building a T-800 Terminator of his own. Whatever, we don’t judge, but the build requires a short-throw linear drive mechanism that can be back-driven, specs that argue for a ball screw. [Andy] goes through the challenges of building such a thing, which mainly involve creating threads with a deep profile and wide pitch. The screw itself wasn’t too hard to cut, although there were some interesting practical details in the thread profile that we’d never heard of before.

The mating nut was another. Rather than try to cut deep internal threads, [Andy] took a sort of “open-face sandwich” approach, creating half-nuts in a single piece of brass using a CNC machine and a ball-nose mill. The threads were completed by cutting the two halves apart and bolting them together — very clever! [Andy] also showed how the balls recirculate in the nut through channels cut into one of the half-nuts.

Whether the results were worth the effort is up to [Andy], but we were just glad to be along for the ride. And if you want a little more detail on lead screws and ball screws, we’ve got just the article for that.

Continue reading “Rolling Your Own Ball Screws” →

Runway-to-Space No More, Reaction Engines Cease Trading

December 4, 2024 by 49 Comments

It’s not often that the passing of a medium sized company on an industrial estate on a damp and soggy former airfield in southern England is worthy of a Hackaday mention, but the news of hypersonic propulsion company Reaction Engines ceasing trading a few weeks ago is one of those moments that causes a second look. Their advanced engine technology may have taken decades to reach the point of sustainable testing, but it held the promise of one day delivering true spaceplanes able to take off from a runway and fly to the edge of the atmosphere before continuing to orbit. It seems their demise is due to a failure to secure more funding.

We’ve written about their work more than once in the past, of their hybrid engines and the development of the advanced cooling system required to deliver air to a jet engine working at extreme speeds.  The rights to this tech will no doubt survive the company, and given that its origins lie in a previously canceled British Aerospace project it’s not impossible that it might return. The dream of a short flight from London to Sydney may be on hold for now then.

Writing this from the UK there’s a slight air of sadness about this news, but given that it’s not the first time a British space effort has failed, we should be used to it by now.

Header: Science Museum London / Science and Society Picture Library, CC BY-SA 2.0

FLOSS Weekly Episode 812: Firefox And The Future

December 4, 2024 by 7 Comments

This week, Jonathan Bennett and David Ruggles chat with Sylvestre and Brian about Firefox! What’s up in the browser world, what’s coming, and what’s the new feature for Firefox on mobile that has Jonathan so excited? Watch to find out!

Subscribe to catch the show live, and come to Hackaday for the rest of the story!

Continue reading “FLOSS Weekly Episode 812: Firefox And The Future” →

Hack On Self: Headphone Friend

December 4, 2024 by 3 Comments

In the last two articles, I talked about two systems relying on audio notifications. The first one is the Alt-Tab annihilator system – a system making use of my window monitoring code to angrily beep at me when I’m getting distracted. The other is the crash prevention system – a small script that helps me avoid an annoying failure mode where I run out of energy before getting myself comfortable for it.

I’ve been appreciating these two systems quite a bit – not only are they at my fingertips, they’re also pretty effective. To this day, I currently use these two systems to help me stay focused as I hack on my own projects or write articles, and they are definitely a mainstay in my self-hacking arsenal.

There is a particular thing I’ve noticed – audio notifications help a fair bit in a way that phone or desktop notifications never would, and, now I have a framework to produce them – in a way that calls for a purpose-tailored device. It’s just wireless headphones, Pi-powered, connected through WiFi, and a library to produce sounds on my computer, but it turns out I can squeeze out a lot out of this simple combination.

Here’s a pocketable device I’ve developed, using off-the-shelf hardware – an audio receiver/transmitter with extra IO, paired to my laptop. And, here’s how I make use of this device’s capabilities to the fullest.

Audio Output

In the “producing sound out of a Pi” article, I’ve mentioned USB-C 3.5mm soundcards. You can use them with a USB-C host port, and you don’t even need any sort of resistors for that – the soundcard doesn’t try and detect state of the CC pin, and why would it, anyway? Get VBUS, GND, D+, and D-, and you got yourself an audio card with high quality output.

Continue reading “Hack On Self: Headphone Friend” →

Did You Know YoSys Knows VHDL Too?

December 4, 2024 by 8 Comments

We’ve been fans of the Yosys / Nextpnr open-source FPGA toolchain for a long while now, and like [Michael] we had no idea that their oss-cad-suite installer sets up everything so that you can write in Verilog or VHDL, your choice. Very cool!

Verilog and VHDL are kind of like the C and ADA of the FPGA world. Verilog will seem familiar to you if you’re used to writing code for computers. For instance, it will turn integer variables into wires that carry the binary values for you. VHDL code looks odd from a software programmer’s perspective because it’s closer to the hardware and strongly typed: an 8-bit integer isn’t the same as eight wires in VHDL. VHDL is a bigger jump if you have software in your brain, but it’s also a lot closer to describing how the hardware actually works.

We learned Verilog, because it’s what Yosys supported. But thanks to GHDL, a VHDL analyzer and synthesizer, and the yosys-ghdl-plugin, you can write your logic in VHDL too. Does this put an end to the FPGA-language holy wars? Thanks, Yosys.

[Michael] points out that this isn’t really news, because the oss-cad-suite install has been doing this for a while now, but like him, it was news to us, and we thought we’d share it with you all.

Want to get started with FPGAs and the open-source toolchain? Our own [Al Williams] wrote up a nice FPGA Boot Camp series that’ll take you from bits to blinking in no time.

The London Underground Is Too Hot, But It’s Not An Easy Fix

December 4, 2024 by 91 Comments

The London Underground is an iconic piece of Victorian era engineering. What started in 1863 quickly became a core piece of infrastructure that would define the modern character of the British capital. It’s grown and changed immensely in the many years that have passed. Sadly, increasing patronage and more trains have created problems that the original designers never envisaged.

Deep in those London tunnels lies an engineering challenge. The Tube is literally cooking itself. Every day, millions of commuters descend into a network of tunnels that have been absorbing heat since the reign of Queen Victoria. Those clay-lined tubes have been soaking up excess thermal energy like a giant underground radiator, and now they’re giving it back with interest. The tunnels are simply too hot, and cooling them down is inordinately difficult.

The Perfect Storm of Thermal Chaos

The Tube’s heat problem isn’t just about one thing gone wrong – it’s about everything gone wrong at once. When Victorian engineers designed these tunnels, cooling wasn’t a major consideration. The tight, compact tunnels were built deep, nestled in the clay beneath London. In the early days, temperatures in the Underground were considered comfortably low.

“The Underground’s the only spot for comfort when the days are hot; it is cooler below.” – London Underground poster, 1926

Originally, the clay surrounding the tunnels sat at around 14°C, acting as a heat sink for the network. However, over the years, with more trains coming and going and more heat pouring in, the temperature has risen. It now typically sits anywhere from 19° to 26 °C. That’s just the earth around the tunnels, though. Air temperatures are worse—hitting as high as 47°C during a 2006 heatwave. The problem has been a continual bugbear of the beloved Tube, with concerns that future heatwaves could see temperatures rise ever higher. Continue reading “The London Underground Is Too Hot, But It’s Not An Easy Fix” →

Sniffing Around Inside A ThinkPad Battery

December 4, 2024 by 24 Comments

For most people, a battery pack that’s misbehaving simply means it’s time to get a new battery. But when the battery in their ThinkPad wasn’t able to muster up more than 20 minutes of runtime, [Shrinath Nimare] saw an opportunity to dig deeper and do a bit of investigating.

The problem seemed to be that the battery pack was reporting that it was 100% charged at just 11.7 V instead of the correct 12.3 V. As it turns out, that 11.7 V figure is only slightly above what the battery should be when its run flat — so in reality, the battery was never actually getting a charge and would report that it was dead after just a few minutes of use. But why?

With a logic analyzer attached to the pins of the battery, [Shrinath] set out to sniff its communications with the ThinkPad.  Even if it wouldn’t lead to fixing the battery pack, the information obtained would potentially be useful for other projects, such as creating a custom high-capacity LiFePO4 pack down the line.

Continue reading “Sniffing Around Inside A ThinkPad Battery” →