Domesticating Plasma With A Gorgeous Live Edge Table

January 19, 2023 by 16 Comments

If you’ve been reading Hackaday for any length of time, you’ll know we don’t often cover woodworking projects here. It’s not because we aren’t impressed with the skill and effort that folks put into them, and truth be told, we occasionally we even feel a pang of envy when looking at the final result. It’s just that, you know…they’re made of wood.

But when [Jay Bowles] of Plasma Channel sent in this live edge wooden table that features not only a pair of custom-made neon tubes but the burned out transistors and ICs from his previous high-voltage exploits — we knew this wasn’t exactly your grandpa’s idea of woodworking. In fact, he wisely offloaded a lot of the dead tree cutting and shaping to the burly gentlemen at the local sawmill so he could better focus his efforts on the sparky bits.

At its core, he’s created what’s generally known as a “river table” — a surface made of two or more pieces of live edge wood (that is, a piece of lumber that features at least one uncut edge) that are linked via a band of colored epoxy which looks like flowing water. It’s not uncommon to embed stones or even fake fish in the epoxy to really sell the underwater effect, but this is Plasma Channel we’re talking about, so [Jay] had other ideas.

The first step was hitting up a local neon supplier who could fabricate a pair of neon tubes which roughly followed the shape of his epoxy river. While he was waiting for them to be finished, [Jay] played around with a clever experimental rig that let him determine how thick he could pour the epoxy over the tubes before he lost the capacitive coupling effect he was going for. By embedding a short length of neon tube off-center in a block of epoxy, he could see how the thickness impacted his ability to manipulate the plasma with a wave of his hand just by flipping it over.

With the tube placed on clear standoffs, he was able to position it at the ideal depth for the final epoxy pours. It was around this time that he scattered the remains of his previous projects on the “bottom” of the river, so they can spend the rest of their days looking up at his latest technical triumph. We’re not sure if this is to punish the fallen silicon for giving up early or to honor their sacrifice in the name of progress, but in either event, we respect anyone who keeps a jar of blown components laying around for ritualistic applications.

Once the table was assembled, all that was left was to power the thing. Given his previous projects, [Jay] had no shortage of existing HV supplies to try out. But not being satisfied with anything in the back catalog, he ended up building a new supply that manages to pump out the required amount of juice while remaining silent (to human ears, at least). The unit is powered by a battery pack cleverly embedded into the legs of the table, and is easy to fiddle with thanks to a pulse-width modulation (PWM) module wired hooked to the input. All the components were then held in place with a wide array of custom brackets courtesy of his newly arrived 3D printer.

There’s a lot to love about this project, and more than a few lessons learned. Whether you’re interested in recreating the Tron-like effect of the neon tubes, or have been contemplating your own epoxy-pour worktable and want to see how a first-timer tackles it, this video is a great resource.

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Linux Fu: UEFI Booting

January 19, 2023 by 30 Comments

Unless your computer is pretty old, it probably uses UEFI (Unified Extensible Firmware Interface) to boot. The idea is that a bootloader picks up files from an EFI partition and uses them to start your operating system. If you use Windows, you get Windows. If you use Linux, there’s a good chance you’ll use Grub which may or may not show you a menu. The problem with Grub is you have to do a lot of configuration to get it to do different things. Granted, distros like Ubuntu have tools that go through and do much of the work for you and if you are satisfied with that, there’s no harm in using Grub to boot and manage multiple operating systems.

An alternative would be rEFInd, which is a nice modern UEFI boot manager. If you are still booting through normal (legacy) BIOS, the installation might be a hassle. But, in general, rEFInd, once installed, just automatically picks up most things, including Windows, Mac, and Linux operating systems and kernels. The biggest reasons you might change the configuration is if you want to hide some things you don’t care about or change the visual theme.

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Mod, Repair And Maintain Your Cassette Tapes With 3D Printed Parts

January 19, 2023 by 5 Comments

The benefit of 3D printers is that they have made it relatively easy to reproduce just about any little plastic thing you might happen to break. If you’re one of the diehards that still has a cassette collection, you might find these 3D prints from Thingiverse useful to repair and maintain any broken tapes you may have.

If you’ve ever stepped on a cassette tape, you’ll know it’s easy to crack the housing and render it unplayable. If you find yourself in this position, you can always 3D print yourself a new cassette tape housing as created by [Ehans_Makes]. The housing design only covers the outer parts of the cassette tape, and doesn’t include the reels, screws, or other components. However, it’s perfect for transplanting the guts of a damaged cassette into a new housing to make it playable once again. The creator recommends using Maxell cassette parts with the design, as it was based on a Maxell cassette shell.

For the modders and musique concrèters out there, [sveltema] designed a simple 3D printed guide for creating tape loops of various lengths. Simply adding a few of these guides to a cassette shell will let you wind a longer continuous loop of tape inside a regular cassette shell. Meanwhile, if you simply want to jazz up your next mixtape gift, consider this cosmetic reel-to-reel mod from [mschiller] that makes your cassettes look altogether more romantic.

Many called the Compact Cassette dead, and yet it continues to live on with enthusiasts. Meanwhile, if you want to learn more about keeping your cassette deck operating at its best, we’ve featured a masterclass on that very topic, too!

New Study Tells Us Where To Hide When The Nukes Are Coming

January 19, 2023 by 70 Comments

Geopolitics is a funny thing. Decades can go by with little concern, only for old grudges to suddenly boil to the surface and get the sabers a-rattlin’. When those sabers happen to be nuclear weapons, it can be enough to have you mulling the value of a bomb shelter in your own backyard.

Yes, every time the world takes a turn for the worse, we start contemplating what we’d do in the event of a nuclear attack. It’s already common knowledge that stout reinforced concrete buildings offer more protection than other flimsier structures. However, a new study has used computer modelling to highlight the best places to hide within such a building to maximise your chances of survival.

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Addressable LEDs From A Z80

January 19, 2023 by 3 Comments

If you buy WS2812s under the Adafruit NeoPixel brand, you’ll receive the advice that “An 8 MHz processor” is required to drive them. “Challenge Accepted!“, says [ShielaDixon], and proceeded to first drive a set from the 7.3 MHz Z80 in an RC2014 retrocomputer, and then repeat the feat from a 3.5 MHz Sinclair ZX Spectrum.

The demos in the videos below the break are all programmed in BASIC, but she quickly reveals that they call a Z80 assembler library which does all the heavy lifting. There’s no microcontroller behind the scenes, save for some glue logic for address decoding, the Z80 is doing all the work. They’re all implemented on a pair of RC2014 extension cards, a bus that has become something of a standard for this type of retrocomputer project.

So the ubiquitous LEDs can be addressed from some surprisingly low-powered silicon, showing that while it might be long in the tooth the Z80 can still do things alongside the new kids. For those of us who had the Sinclair machines back in the day it’s particularly pleasing to see boundaries still being pushed at, as for example in when a Z80 was (almost) persuaded to have a protected mode.

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LED Driver Circuit For Safety Hat Sucks Single AAA Cell Dry

January 19, 2023 by 21 Comments

[Petteri Aimonen] created an omnidirectional LED safety light to cling to his child’s winter hat in an effort to increase visibility during the dark winter months, but the design is also great example of how to use the Microchip MCP1640 — a regulated DC-DC step-up power supply that can run the LEDs off a single AAA cell. The chip also provides a few neat tricks, like single-button on/off functionality that fully disconnects the load, consuming only 1 µA in standby.

[Petteri]’s design delivers 3 mA to each of eight surface-mount LEDs (which he says is actually a bit too bright) for a total of about 20 hours from one alkaline AAA cell. The single-layer PCB is encased in a clear acrylic and polycarbonate enclosure to resist moisture. A transistor and a few passives allow a SPST switch to act as an on/off switch: a short press turns the unit on, and a long press of about a second turns it back off.

One side effect is that the “off” functionality will no longer work once the AAA cell drained too badly, but [Petteri] optimistically points out that this could be considered a feature: when the unit can no longer be turned off, it’s time to replace the battery!

The usual way to suck a battery dry is to use a Joule Thief, and while this design also lights LEDs, it offers more features and could be adapted for other uses easily. Interested? [Petteri] offers the schematic, KiCAD file for the PCB, and SVG drawing of the enclosure for download near the bottom of the project page.

3D Printed Berlin Uhr Is An Attractive Germanic Clock

January 18, 2023 by 22 Comments

As much as Big Ben steals the spotlight when it comes to big public clocks, the Berlin Uhr is a much beloved digital communal timepiece. [RuudK5] developed their own 3D printed replica of this 1980s German icon.

The revision we see today is the [RuddK5]’s third attempt at replicating the Berlin Uhr. The clock features a design with four linear elements with a round light on top. The top light is responsible for blinking the seconds. The lowest line has four lights, each indicating one minute, while the next line has eleven lights, marking out five-minute intervals. Above that, the top two lines represent one hour and five hour blocks respectively. It’s a display unlike most other clocks out there, but when you learn it, it’s easy enough to use.

[RuddK5]’s replica relies on addressable LED strips to serve as the individual lighting elements. The strips are placed inside a 3D printed housing that is a scale replica of the real thing. Running the show is an ESP32 microcontroller, which is charged with getting accurate time updates from an NTP server.

Great design really does shine through, and this clock looks just as appealing at the small scale as it does lofted on a pole over the city of Berlin. If you prefer to read out the time in a simpler fashion though, we’ve featured plenty of clocks like that, as well!