Day: July 13, 2024

Print Wave Metal Casting

July 13, 2024 by 4 Comments

Direct 3D printing of metal remains out of reach for the hobbyist at the moment, so casting is often the next best thing, particularly given the limitations of 3D printed metals. [Denny] from Shake the Future shows us how to simplify the process with “print wave metal casting.”

The first step of printing a PLA object will seem familiar to any 3D print to metal process, but the main differentiator here is pouring the investment casting on the printer build plate itself. We like how he used some G-code to shake the build plate to help remove bubbles. Once the plaster solidifies, the plastic and mold are placed in the microwave to soften the plastic for removal.

The plaster is dried in an oven (or air fryer) and then [Denny] bolts the mold together for the casting process. Adding a vacuum helps with the surface finish, but you can always polish the metal with a generous helping of elbow grease.

If [Denny] seems familiar, you might remember his very detailed breakdown of microwave casting. We’ve seen plenty of different approaches to metal casting over the years here. Need a part in another material? How about casting concrete or resin?

Thanks to [marble] on the Hackaday Discord for the tip!

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C++ Design Patterns For Low-Latency Applications

July 13, 2024 by 41 Comments

With performance optimizations seemingly having lost their relevance in an era of ever-increasing hardware performance, there are still many good reasons to spend some time optimizing code. In a recent preprint article by [Paul Bilokon] and [Burak Gunduz] of the Imperial College London the focus is specifically on low-latency patterns that are relevant for applications such as high-frequency trading (HFT). In HFT the small margins are compensated for by churning through absolutely massive volumes of trades, all of which relies on extremely low latency to gain every advantage. Although FPGA-based solutions are very common in HFT due their low-latency, high-parallelism, C++ is the main language being used beyond FPGAs.

Although many of the optimizations listed in the paper are quite obvious, such as prewarming the CPU caches, using constexpr, loop unrolling and use of inlining, other patterns are less obvious, such as hotpath versus coldpath. This overlaps with the branch reduction pattern, with both patterns involving the separation of commonly and rarely executed code (like error handling and logging), improving use of the CPU’s caches and preventing branch mispredictions, as the benchmarks (using Google Benchmark) clearly demonstrates. All design patterns can also be found in the GitHub repository.

Other interesting tidbits are the impact of signed and unsigned comparisons, mixing floating point datatypes and of course lock-free programming using a ring buffer design. Only missing from this list appears to be aligned vs unaligned memory accesses and zero-copy optimizations, but those should be easy additions to implement and test next to the other optimizations in this paper.

Axial 3D Printer Aces Test Aboard Virgin Spaceplane

July 13, 2024 by 32 Comments

Here on Earth, being able to 3D print replacement parts is handy, but rarely necessary. If you’ve got a broken o-ring, printing one out is just saving you a trip to the hardware store. But on the Moon, Mars, or in deep space, that broken component could be the difference between life and death. In such an environment, the ability to print replacement parts on demand promises to be a game changer.

Which is why the recent successful test of a next-generation 3D printer developed by a group of Berkeley researchers is so exciting. During a sub-orbital flight aboard Virgin Galactic’s Unity spaceplane, the SpaceCAL printer was able to rapidly produce four test prints using a unique printing technology known as computed axial lithography (CAL).

Continue reading “Axial 3D Printer Aces Test Aboard Virgin Spaceplane” →

Docker-Powered Remote Gaming With Games On Whales

July 13, 2024 by 15 Comments

Cloud gaming services allow even relatively meager devices like set top boxes and cheap Chromebooks play the latest and greatest titles. It’s not perfect of course — latency is the number one issue as the player’s controller inputs need to be sent out to the server —  but if you’ve got a fast enough connection it’s better than nothing. Interested in experimenting with the tech on your own terms? The open source Games on Whales project is here to make that a reality.

As you might have guessed from the name, Games on Whales uses Linux and Docker as core components in its remote gaming system. With the software installed on a headless server, multiple users can create virtual desktop environments on the same machine, with each spawning as a separate process on the host computer. This means that all of the hardware of the host can be shared without needing to do anything complicated like setting up GPU pass-through. The main Docker container can spin up more containers as needed.

Of course there will obviously be limits to what any given hardware configuration will be able to support in terms of number of concurrent users and the demands of each stream. But for someone who wants to host a server for their friends or something even simpler like not having to put a powerful gaming PC in the living room, this is a real game-changer. For those not up to speed on Docker yet, we recently featured a guide on getting started with this powerful tool since it does take some practice to wrap one’s mind around at first.

The NSA Is Defeated By A 1950s Tape Recorder. Can You Help Them?

July 13, 2024 by 57 Comments

One of the towering figures in the evolution of computer science was Grace Hopper, an American mathematician, academic, and Naval reservist, whose work gave us the first programming languages, compilers, and much more. Sadly she passed away in 1992, so her wisdom hasn’t directly informed the Internet Age in the manner of some of her surviving contemporaries.

During her life she gave many lectures though, and as [Michael Ravnitzky] discovered, one of them was recorded on video tape and resides in the archives of America’s National Security Agency. With the title “Future Possibilities: Data, Hardware, Software, and People”, it was the subject of a Freedom Of Information request. This in turn was denied, on the grounds that “Without being able to view the tapes, NSA has no way to verify their responsiveness”. In short, the recording lies on Ampex 1″ reel-to-reel video tape, which the NSA claims no longer to be able to read.

It’s fairly obvious from that response that the agency has no desire to oblige, and we’d be very surprised to find that they keep a working Ampex video system to hand on the off-chance that a passing researcher might ask for an archive tape. But at the same time it’s also obvious that a lecture from Rear Admiral Hopper is an artifact of international importance that should be preserved and available for study. It’s an interesting thought exercise to guess how many phone calls Hackaday would have to make to secure access to a working Ampex video recorder, and since we think for us that number would be surprisingly low it’s likely the NSA know exactly who to call if they needed that tape viewed in a hurry. We don’t have influence over secretive government agencies, but if we did we’d be calling shame on them at this point.

If you’re curious about Grace Hopper, we’ve talked about her work here in the past.

Thanks [F4GRX] for the tip.

Ampex image: Telecineguy., Public domain.

It’s Not Unusual To Love Hacking

July 13, 2024 by 21 Comments

Most of what we do here at Hackaday is look out for cool projects and then write them up so that you all know about them. Nothing is better than being really stoked about a clever hack and then being able to share it with tens of thousands of like-minded folks. Sure, it’s our job, but we really do it because we love to share. And it’s clear that you all do too! After all, we write up the hacks that you document for us.

We recently featured a hack where the guy who did the work in question said that he didn’t think it was “worthy of Hackaday”. (Of course, it was!) And I don’t like that sentiment at all, honestly, because a hack that you enjoyed doing is a hack worth sharing, even if just for sharing the joy of doing it, and that came across fully.

Of course we gladly feature the ultra-bravado hacks where the nearly impossible is made real. But there’s equal value in the simple hacks that inspire others to pursue one odd path or another. Or even pieces where there’s no hack involved, but simply the sharing of something cool.

This week, [Arya Voronova] wrote a piece about her experience using MicroPython on embedded devices, and it apparently resonated with a lot of our readers. It’s not a deep-dive into MicroPython, or a mind-bending abuse of the language. Instead, it’s a simple “this is what I love about doing things this way”, and that’s a great perspective that often gets lost when we get deep in the technical weeds.

I had the same realization a few months back at Hackaday Europe. In the lightning talks, most everyone gave talks about cool projects that they are working on, and they’re absolutely worth watching for that. [Jaap Meijers] gave a wonderful talk about making animated QR codes, but it wasn’t about how he invented animated QR codes, because he was just using someone else’s project. Instead, it was about how neat he thought someone else’s work was, and how he really wanted to share it with us. (And now you know too.)

Epic hacks are fantastic, no question. But the simple expression of the love of hacking, whether in words or in the doing, is equally important. Show us your work, but don’t forget to show us your joy along the way.

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Particle Physics On A Small, Affordable PCB

July 13, 2024 by 7 Comments

Experimenting in the world of particle physics probably brings to mind large, expensive pieces of equipment like particle accelerators, or at least exotic elements or isotopes that most of us can’t easily find. But plenty of common objects emit various particles, and it turns out that detecting these particles does not require government backing or acres of test equipment. In fact, you can get this job done with a few readily-available parts and [Tim] shows us how it’s done with his latest project.

The goal of his build is to have a working particle detector for less than $10 per board, although he’s making them in bulk to be used in an educational setting. The board uses a set of photodiodes enclosed in a protective PCB sandwich to detect beta particles from a Potassium-40 source. The high-energy electron interacts with the semiconductor in the photodiode and creates a measurable voltage pulse, which can be detected and recorded by the microcontroller on the board. For this build an RP2040 chip is being used, with a number of layers of amplification between it and the photodetector array used to get signals that the microcontroller can read.

Getting particle physics equipment into the hands of citizen scientists is becoming a lot more common thanks to builds like this which leverage the quirks of semiconductors to do something slightly outside their normal use case, and of course the people building them releasing their projects’ documentation on GitHub. We’ve also seen an interesting muon detector with a price tag of around $100 and an alpha particle detector which uses a copper wire with a high voltage to do its work.