Author: Bryan Cockfield

1708 Articles

Reliable 3D Printing With Ceramic Slurry

June 16, 2023 by 4 Comments

3D printing is at its most accessible (and most affordable) when printing in various plastics or resin. Printers of this sort are available for less than the cost of plenty of common power tools. Printing in materials other than plastic, though, can be a bit more involved. There are printers now for various metals and even concrete, but these can be orders of magnitude more expensive than their plastic cousins. And then there are materials which haven’t really materialized into a viable 3D printing system. Ceramic is one of those, and while there are some printers that can print in ceramic, this latest printer makes some excellent strides in the technology.

Existing technology for printing in ceramic uses a type of ceramic slurry as the print medium, and then curing it with ultraviolet light to solidify the material. The problem with ultraviolet light is that it doesn’t penetrate particularly far into the slurry, only meaningfully curing the outside portions. This can lead to problems, especially around support structures, with the viability of the prints. The key improvement that the team at Jiangnan University made was using near-infrared light to cure the prints instead, allowing the energy to penetrate much further into the material for better curing. This also greatly reduces or eliminates the need for supports in the print.

The paper about the method is available in full at Nature, documenting all of the details surrounding this new system. It may be a while until this method is available to a wider audience, though. If you can get by with a print material that’s a little less exotic, it’s not too hard to get a metal 3D printer, as long as you are familiar with a bit of electrochemistry.

Long-Distance Wi-Fi With Steam Deck Server

June 16, 2023 by 11 Comments

It’s no secret that the Steam Deck is a powerful computer, especially for its price point. It has to be capable enough to run modern PC games while being comfortable as a handheld, all while having a useful amount of battery life. Thankfully Valve didn’t lock down the device like most smartphone manufacturers, allowing the computer to run whatever operating system and software the true owner of the device wants to run. That means that a whole world of options is open for this novel computer, like using it to set up an 802.11ah Wi-Fi network over some pretty impressive distances.

Of course the Steam Deck is more of a means to an end for this project; the real star of the show is DragonOS, a Debian-based Linux distribution put together by [Aaron] to enable easy access to the tools needed for plenty of software-defined radio projects like this one. Here, he’s using it to set up a long-distance Wi-Fi network on one side of a lake, then testing it by motoring over to the other side of the lake to access the data from the KrakenSDR setup running on the Deck, as well as performing real-time capture of IQ data that was being automatically demodulated and feed internally to whispercpp.

While no one will be streaming 4K video over 802.11ah, it’s more than capable of supporting small amounts of data over relatively large distances, and [Aaron] was easily able to SSH to his access point from over a kilometer away with it. If the lake scenery in the project seems familiar at all, it’s because this project is an extension of another one of his DragonOS projects using a slightly lower frequency to do some impressive direction-finding, also using the Steam Deck as a base of operations.

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The First Search Engines, Built By Librarians

June 11, 2023 by 14 Comments

Before the Internet became the advertisement generator we know and love today, interspersed with interesting information here and there, it was originally a network of computers largely among various universities. This was even before the world-wide web and HTML which means that the people using these proto-networks, mostly researchers and other academics, had to build things we might take for granted from the ground up. One of those was one of the first search engines, built by the librarians who were cataloging all of the research in their universities, and using their relatively primitive computer networks to store and retrieve all of this information.

This search engine was called SUPARS, the Syracuse University Psychological Abstracts Retrieval Service. It was originally built for psychology research papers, and perhaps unsurprisingly the psychologists at the university also used this new system as the basis for understanding how humans would interact with computers. This was the 1970s after all, and most people had never used a computer, so documenting how they used search engine led to some important breakthroughs in the way we think about the best ways of designing systems like these.

The search engine was technically revolutionary for the time as well. It was among the first to allow text to be searched within documents and saved previous searches for users and researchers to access and learn from. The experiment was driven by the need to support researchers in a future where reference librarians would need assistance dealing with more and more information in their libraries, and it highlighted the challenges of vocabulary control in free-text searching.

The visionaries behind SUPARS recognized the changing landscape of research and designed for the future that would rely on networked computer systems. Their contributions expanded the understanding of how technology could shape human communication and effectiveness, and while they might not have imagined the world we are currently in, they certainly paved the way for the advances that led to its widespread adoption even outside a university setting. There were some false starts along that path, though.

Siphoning Energy From Power Lines

June 11, 2023 by 108 Comments

The discovery and implementation of alternating current revolutionized the entire world little more than a century ago. Without it, we’d all have inefficient, small neighborhood power plants sending direct current in short, local circuits. Alternating current switches the direction of current many times a second, causing all kinds of magnetic field interactions that result in being able to send electricity extremely long distances without the resistive losses of a DC circuit. The major downside, though, is that AC circuits tend to have charging losses due to this back-and-forth motion, but this lost energy can actually be harvested with something like this custom-built transformer.

[Hyperspace Pilot] hand-wound this ferromagnetic-core transformer using almost two kilometers of 28-gauge magnet wire. The more loops of wire, the more the transformer will be able to couple with magnetic fields generated by the current flowing in other circuits. The other thing that it needs to do is resonate at a specific frequency, which is accomplished by using a small capacitor to tune the circuit to the mains frequency. With the tuning done, holding the circuit near his breaker panel with the dryer and air conditioning running generates around five volts. There’s not much that can be done with this other than hook up a small LED, since the current generated is also fairly low, but it’s an impressive proof of concept.

After some more testing, [Hyperspace Pilot] found that the total power draw of his transformer is only on the order of about 50 microwatts in an ideal setting where the neutral or ground wire wasn’t nearby, so it’s not the most economical way to steal electricity. On the other hand, it could still be useful for detecting current flow in a circuit without having to directly interact with it. And, it turns out that there are better ways of saving on your electricity bill provided you have a smart meter and the right kind of energy-saving appliances anyway.

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Crafting Ribbon Cables For Retro Hardware

June 10, 2023 by 23 Comments

Building a modern computer is something plenty of us have done, and with various tools available to ensure that essentially the only thing required of the end user is to select parts and have them delivered via one’s favorite (or least expensive) online retailer. Not so with retro hardware, though. While some parts can be found used on reselling sites like eBay, often the only other option is to rebuild parts from scratch. This is sometimes the best option too, as things like ribbon cables age poorly and invisible problems with them can cause knock-on effects that feel like wild goose chases when troubleshooting. Here’s how to build your own ribbon cables for your retro machines.

[Mike] is leading us on this build because he’s been working on an old tower desktop he’s calling Rosetta which he wants to be able to use to host five different floppy disk types and convert files from one type to another. Of course the old hardware and software being used won’t support five floppy disk drives at the same time so he has a few switches involved as well. To get everything buttoned up neatly in the case he’s building his own ribbon cables to save space, especially since with his custom cables he won’t have the extraneous extra connectors that these cables are famous for.

Even though, as [Mike] notes, you can’t really buy these cables directly anymore thanks to the technology’s obsolescence, you can still find the tools and parts you’d need to create them from scratch including the ribbon, connectors, and crimping tools. Even the strain relief for these wide, fragile connectors is available and possible to build into these projects. It ends up cleaning up the build quite nicely, and he won’t be chasing down any gremlins caused by decades-old degraded multi-conductor cables. And, even though [Mike] demonstrated the floppy disk drive cables in this build, ribbon cable can be used for all kinds of things including IDE drive connectors and even GPIO cables for modern electronics projects.

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Using FreeCAD To Replace OEM Parts

June 10, 2023 by 46 Comments

As much as we might all like it if manufacturers supported their products indefinitely with software updates or replacement parts, this just isn’t feasible. Companies fail or get traded, technologies evolve, and there’s also an economic argument against creating parts for things that are extremely old or weren’t popular in the first place. So, for something like restoring an old car, you might have to resort to fabricating replacement parts for your build on your own. [MangoJelly] shows us how to build our own replacement parts in FreeCAD in this series of videos.

The build does assume that the original drawings or specifications for the part are still available, but with those in hand FreeCAD is capable of importing them and then the model scaling to match the original specs shown. This video goes about recreating a hinge on an old truck, so with the drawings in hand the part is essentially traced out using the software, eventually expanding it into all three dimensions using all of the tools available in FreeCAD. One of the keys to FreeCAD is the various workbenches available that all have their own sets of tools, and being able to navigate between them is key to a build like this.

FreeCAD itself is an excellent tool for anyone repairing old vehicles like this or those making 3D prints, designing floorplans for houses, or really anything you might need to model in a computer before bringing the idea into reality. It does have a steep learning curve (not unlike other CAD software) so it helps to have a video series like this if you’re only just getting started or looking to further hone your design skills, but the fact that it’s free and open-source make it extremely attractive compared to its competitors.

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3D Printing LEGO-like Blocks

June 10, 2023 by 8 Comments

LEGO are perhaps the perfect children’s toy, at least until you step on the errant brick while walking around the house. Available in all kinds of sets with varying themes and characters, they encourage building and creativity in kids like no other. Those with 3D printers might have considered creating their own specialty blocks, but the manufacturing of real LEGO blocks involves steel molds with extremely tight tolerances far outside the realm of most 3D printers. To print blocks capable of interconnecting in a similar way involves taking advantage of the characteristics of 3D printers and their materials instead, as [CNC Kitchen] demonstrates with these PrintABloks.

The PrintABlok was the idea of [Joe Larson] aka [3D Printing Professor] and is built around a one-unit base block, which has holes on all of its sides, paired with small connecting pieces which are placed in the holes to connect the various blocks to one another. Using your CAD software of choice (although they were originally built using Blender), the base block can be lengthened or widened for printing various different types of blocks, and the diamond-shaped hole can even be added to various prints that aren’t blocks at all. This means that a wide variety of parts can be made, all designed to interlock with the bricks or various other shapes. [Joe] even created an array of themed sets like robots, castles, and dinosaurs and although he sells these more complex models, he released his base set and interconnection mechanism for free and is available for anyone to use.

Another perk of the PrintABlok system is that they are scalable, mitigating safety risks for smaller children that might try to swallow some of the smaller parts. It’s an excellent way to put the 3D printer to work if there are any children around in the house. But this isn’t the only LEGO-inspired build we’ve ever seen, and they aren’t always going to be used to make children’s toys. [Ivan] recently used similar 3D-printed interlocking bricks more in the style of LEGO Technic to attempt to build a human-rideable go-kart.

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