Could Reticulum Power A Post-Internet Network?

July 20, 2026 by 1 Comment

These days, it is easy to think you always have access to the Internet. But some wonder if — in spite of its ARPANET, nuclear-war-planning heritage — you can actually count on it to be there when things go pear-shaped. [The Tech Prepper], as you might imagine, is quite concerned with that last question, and is flogging Reticulum over high-frequency radio as a post-internet network in a video embedded below.

Reticulum is a cryptographic network stack, fully decentralized and amazing from a cyberpunk/hacker/survivalist perspective. Unfortunately for [The Tech Prepper], until the you-know-what hits the ventilation unit and the FCC and its counterparts in other countries are too busy to be concerned with such trifles, encrypted signals are banned on ham radio bands just about everywhere. That’s why his demo is using a dummy load on the Mercury HF modem instead of an antenna: the feds don’t care if the signal doesn’t leave the building. The video shows how to replicate the setup using his EmComm Tools suite on Ubuntu.

Perhaps more interesting is his vision of a Post-Internet network, be it in a disaster scenario, as he envisions, or simply because we get sick of what the internet has become. The idea of easily hooking an open-source radio modem to a PC running modem73, open-source SDR software, has a certain appeal. Reticulum isn’t your only option there: modem73 will let you run a BBS in the clear — that is, unencrypted and legal to transmit — and let’s face it, wasn’t life online more fun in BBS days?

This isn’t the first time we’ve seen the Reticulum network stack, but last time it was operating at considerably shorter ranges over LoRA. 

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Seven Ways To Install Magnets Into Your 3D Prints

July 19, 2026 by 3 Comments

Magnets are awesome, so it’s no wonder we love to add them to our 3D prints. Doing so in a way that will actually last is harder, with thermal creep being one reason a simple friction fit will loosen over time, and using super glue to hold a magnet in place can be messy. In a recent video, [Slant 3D] covers seven ways to install magnets in 3D prints without resorting to glue, along with the advantages and disadvantages of each.

With friction, the argument is that you can still use them, but you’d want to use something like cylindrical magnets rather than flat magnets to increase the friction with the thermoplastic. Using an arbor press rather than human primate hand power is also beneficial.

Rather than installing magnets halfway through a print with all the logistics that entails, you can use side slots to install said magnet into, which is much easier, but as with all embedded magnets, you get that plastic barrier between the magnet and its target.

Other methods involve using a bit of extra material that you need to push the magnet past, using something like an arbor press, so the magnets should never just fall out. A wildcard here: spherical magnets, which can be locked in using a similar method, while automatically orienting themselves to an opposing magnet.

The final tip is to never use two magnets in a magnetic lock. Instead, use a cheaper ball bearing or a similar plain metal part on one side instead. Magnets tend to be much more brittle than whatever stainless steel ball bearing or washer you can use on the other side.

Of course, people will always try to install magnets during an FDM print, but before they try to do that anyway, they really should learn about the fascinating ways in which magnets can ruin print beds, destroy nozzles, and otherwise make a total mess of a print. Magnets seem magical. Maybe they are.

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Pong-like Cabinet For Classic Dinosaur Jumper

July 19, 2026 by No comments

Back when Google ran a functional search engine, there used to be all kinds of quirky, fun antics hidden in their products. From Easter eggs in certain search results, to a flight simulator hidden in Google Maps, to funny, engaging April Fools jokes, it was a lighter, less corporate time. Now, though, to recreate any of that early Google magic, we have to do it on our own, and [Paul] has come up with an arcade cabinet for the classic Google Chrome dinosaur game that does just that.

Although the Dinosaur Game is still available in modern versions of Google Chrome, it lends itself almost perfectly to an arcade cabinet. Built from 12 mm plywood, the cabinet is standard DIY arcade fare with a built-in shelf to house the electronics and a 4:3 flatscreen monitor for a display. The Raspberry Pi 3B is also just enough to run the game, but the software running on it is unique. The Pi runs an operating system called FullPageOS, which automatically loads a modified version of the Dino jumper in full-screen mode. It’s been changed to look more like an arcade game than a browser Easter egg, with features like a leaderboard and an automatic-play screensaver mode, and the build is rounded out by a cactus-shaped scratching post to accompany the cabinet.

As for gameplay, we couldn’t ask for a simpler user interface. A single button is all that’s needed for this game, and it’s surprisingly engaging. It is a bit large for a single-button game, even with its reduced-width cabinet, so if you’re looking for something smaller, you could always base it on a tabletop arcade system instead.

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Hackaday Links: July 19, 2026

July 19, 2026 by 4 Comments

We’ll start this week off by giving our congratulations to Skyroot Aerospace of India for successfully launching the country’s first privately developed orbital rocket yesterday. The company’s Vikram-1 booster stands 24 m (79 ft) tall and uses a somewhat unusual four-stage arrangement, with the first three stages using solid propellant and the final liquid-fueled stage being responsible for putting the payload into a precise orbit. With this successful launch, India becomes only the third country in the world with a private company capable of performing orbital launches.

Generally, the rocket should be moving when the countdown hits zero.

On the other end of the spectrum, we have SpaceX’s prototype Starship, which elected not to leave Earth during a last-second (literally) launch termination on Thursday. Aborted launches are, of course, nothing new in the world of rocketry, especially when dealing with an in-development vehicle that has 33 engines that need to fire up at the same moment before it can leave the pad. But this dramatic abort was unique as it was the first time lift-off of the massive 124.4 meter (408 ft) rocket had been called off when the engines were already running.

Onboard systems took advantage of the very narrow window between the time the Raptor engines are switched on and the rocket actually leaves the launchpad to decide that it was not a good day to visit space after all. Word from SpaceX is that two of the Raptor engines on the first stage will be replaced and that they should be ready to make another launch attempt sometime this upcoming week.

While getting rockets off the ground is never easy, one thing that seems to have no trouble going up is the price of gasoline. Even still, Americans seem largely uninterested in electric vehicles, or at the very least, the slate of EVs that are currently available to them — especially now that the $7,500 federal tax credit has ended. Yesterday, TechCrunch ran an article about all the EVs that have exited the US market over the last year due to stagnant sales or import difficulties, and it’s quite a list.

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Automated Pressure Advance Using A Bed-Leveling Sensor

July 19, 2026 by 5 Comments

One of the most crucial aspects of FDM 3D printing is ensuring sufficient material is extruded. Determining the right flow rate can be done manually, but some printers these days automatically perform this adjustment, which is very convenient. [Stefan] of CNC Kitchen investigates how to add similar functionality using existing bed-leveling sensors.

A major complication with extrusion in FDM printers is that the flow rate has to fit the printing speed. However, you can’t just immediately speed up or reduce the flow rate, as the melting filament is flexible and thus acts like a spring, especially as the extruder is exerting significant force on the filament, which adds compression.

The moment you reduce or increase the speed of the nozzle, you can get over- or under-extrusion, but the delayed response by the extruded filament means that you have to adjust for this change in advance. Ergo, the name ‘pressure advance’, also known as the K-value. Obviously, this is a parameter that differs with each material, printer, and other factors, so a direct measurement is always the best.

In the Bambu Lab X1 FDM printer, a Lidar scanner was used to scan various test patterns to automatically determine the optimal setting. This was later moved to the purge section of the extruder in newer Bambu Lab printers. On other FDM printers, the only available sensor in that area is typically the pressure sensor for bed leveling. Could this sensor make a similar measurement?

This wasn’t just an idle thought, but was inspired by the Snapmaker U1, which runs open-source Klipper, with tantalizing glimpses of how it does pressure-advance sensing in its extruder. This extruder also only contains a load cell, as do some Prusa printers. These much more open printers thus provided a test bed for some experimentation.

With load cell data available, [Stefan] measured how various extrusion rates affect the load cell, which can then theoretically be correlated with the appropriate K-values for specific transitions. He created a calibration tool for a range of Prusa printers that works with stock firmware, though this is definitely still a work in progress. There are also a couple of similar open-source projects, such as this Auto PA Calibration project by [Mark].

Overall, K-value presets tend to work pretty well, but adding a pressure-advance calibration feature to existing FDM printers is definitely an interesting idea. There’s also the prospect of lateral sensing using this same bed-leveling sensor, which could allow the printer to sense much more than just the bed.

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Recycling Laptops And IMacs Makes PC Building Fun And Affordable Again

July 19, 2026 by 25 Comments

Building a PC used to be a fun adventure — what’s the latest, what’s the greatest, what can I afford? Well, that last question seems to have taken over and sucked all the fun out for a lot of people. [Matt] from [DIY Perks] on YouTube has hit upon a solution that’s brought back the fun, at least for him: recycling! The video is embedded below, and he runs a forum whose thread has more details.

Long story short, though, he’s flagging recycled laptop components as both good value for money and a fun rabbit hole to go down researching parts. The best part, of course, is that you can get a mobo with 32GB of RAM soldered on, and embedded RTX graphics, and a decent processor for about what you’d pay for that RAM on sticks these days. The big hack is getting the dang thing started: he needed to make a single-pin ribbon cable after identifying which pin on the keyboard membrane hit the power button. If you can score a laptop that does not power on from the keyboard, you’ll have an easier time in that regard.

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Remembering The Zilog Z80 As It Turns Fifty Years Old

July 19, 2026 by 21 Comments

Perhaps the saddest thing about the Zilog Z80 is that this humble 8-bit microprocessor wasn’t allowed to live until its 50th birthday. This, fortunately, doesn’t prevent people like [David Oberhollenzer] from reminiscing on this influential processor and what it means to them personally.

First released in July of 1976, this humble 8-bit miracle would go on to power not just a range of home computers, but also be found in everything from industrial controllers to arcade systems. Despite this success, the new owner of Zilog — Littelfuse — decided to put an end to this winning streak in 2024 for the stand-alone processor and its peripherals.

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