Improving FDM Filament Drying With A Spot Of Vacuum

March 31, 2026 by Maya Posch 1 Comment

Keeping your filament safely away from moisture exposure is one of the most crucial aspects of getting a good 3D print, with equipment like a filament dryer a standard piece of equipment to help drive accumulated moisture out of filament prior to printing or storage. Generally such filament dryers use hot air to accomplish this task over the course of a few hours, but this is not very efficient for a number of reasons. Increasing the vaporization rate of water without significantly more power use should namely be quite straightforward.

The key here is the vapor pressure of a liquid, specifically the point at which it begins to transition between its liquid and gaseous phases, also known as the boiling point. This point is defined by both temperature and atmospheric pressure, with either factor being adjustable. In a pressure cooker this principle is for example used to increase the boiling temperature of water, while for our drying purposes we can instead reduce the pressure in order to lower the boiling point.

Although a lower pressure is naturally more effective, we can investigate the best balance between convenience and effectiveness.

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A laptop communicating with the drone via an Arduino

Reverse-Engineering The Holy Stone H120D Drone

March 31, 2026 by Julian Scheffers 1 Comment

There are plenty of drones (and other gadgets) you can buy online that use proprietary control protocols. Of course, reverse-engineering one of these protocols is a hacker community classic. Today, [Zac Turner] shows us how this GPS drone can be autonomously controlled by a simple Arduino program or Python script.

What started as [Zac] sniffing some UDP packets quickly evolved into him decompiling the Android app to figure out what’s going on inside. He talks about how the launch command needs accurate GPS, how there’s several hidden features not used by the Android app, et cetera. And it’s not like it’s just another Linux SoC in there, either. No, there’s a proper Real-Time Operating System (RTOS) running, with a shell and a telnet interface. The list of small curiosities goes on.

After he finished reverse-engineering the protocol, he built some Python scripts, through which you can see the camera feed and control the drone remotely. He also went on to make an Arduino program that can do the latter using an Arduino Nano 33 IoT.

Solar Balconies Take Europe By Storm

March 31, 2026 by Lewin Day 52 Comments

Solar power has been around for a long time now. Once upon a time, it was mostly the preserve of research projects and large-scale municipal installations. Eventually, as the technology grew ever cheaper, rooftop solar came along, and cashed-up homeowners rushed to throw panels on their homes to slash their power bills and even make money in some cases.

Those in apartments or rented accommodations had largely been left out of the solar revolution. That was, until the advent of balcony solar. Popular in Germany, but little known in the rest of the world, the concept has brought home power generation to a larger market than ever.

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Refill UV Printer Ink Cartridges Like It’s The Late 90s

March 31, 2026 by Donald Papp 1 Comment

The Eufymake E1 is a recently-released prosumer UV printer that can print high-resolution color images onto pretty much anything. It also uses proprietary ink cartridges (which integrate a magnetic stirrer, nice) which are far more expensive than UV ink in bulk. So [charliex] set out to figure out how to refill the ink cartridges, including the cleaning cartridge.

If one doesn’t mind a bit of fiddling, cartridges can be refilled without having to add any new holes.

UV printing in general is a bit of a maintenance hog, which has helped keep it from hobbyist use. UV ink doesn’t really like sitting idle in a machine, but the E1 automates cleaning and flushing of the print head as well as having swappable cartridges for each ink. This makes it a lot more user-friendly than UV printing has historically been.

The cartridge hardware can have a longer serviceable life than the ink inside, so it makes sense to try to refill them. There are more reasons to do this than just limiting costs. What if one wishes to print and the parent company is sold out of cartridges? What if they shut down? Refilling cartridges, and emptying waste from the cleaning cartridge, would become imperatives — lest an expensive prosumer UV printer turn into a paperweight. Thankfully software DRM control of the cartridges seems limited, at least so far.

Refilling cartridges can be carefully done with syringes combined with manual bypass of spring-loaded valve mechanisms. Emptying the cleaning cartridge can similarly be done by syringe, and it even has a hidden refill port under some plastic at its top.

[charliex] approaches all of this from a reverse-engineering perspective, indeed, he has a whole separate blog post about the software for the printer. So his solution is much more informed and elegant than, for example, just melting a new refill hole in the side of the things. It’s an interesting read, so check it out.

Our own Tom Nardi took a close, hands-on look at the E1 printer last year and came away pretty impressed with its capabilities. The cartridges are a big part of the user-friendliness of the system, but we hope there remains a viable option for manual refill for those of us who want to control costs or don’t wish to be locked in, and don’t mind violating a warranty or two in the process.

The D In DNS Stands For DOOM

March 31, 2026 by Maya Posch 3 Comments

As literally everything ought to be able to play DOOM in some fashion, [Adam Rice] recently set out to make the venerable DNS finally play the game after far too many decades of being DOOM-less. You may be wondering how video games and a boring domain records database relate to each other. This is where DNS TXT records come into play, which are essentially fields for arbitrary data with no requirements or limitations on this payload, other than a 2,000 character limit.

Add to this the concept of DNS zones which can contain thousands of records and the inkling of a plan begins to form. Essentially the entire game (in C#) is fetched from TXT records, loaded into memory and run from there. This is in some ways a benign form of how DNS TXT records can be abused by people with less harmless intentions, though [Adam] admits to using the Claude chatbot to help with the code, so YMMV.

The engine and WAD file with the game’s resources are compressed to fit into 1.7 MB along with a 1.2 MB DLL bundle, requiring 1,966 TXT records in Base64 encoding on a Cloudflare Pro DNS zone. With a free Cloudflare account you’d need to split it across multiple zones. With the TXT records synced across the globe, every DNS server in the world now has a copy of DOOM on it, for better or worse.

You can find the project source on GitHub if you want to give this a shake yourself.

Thanks to [MrRTFM] for the tip.

The ikea desk, with the spectrometer on the far left.

PDP-11 Lives In Literal Computer Desk Once More

March 30, 2026 by Tyler August 3 Comments

When you think of iconic parings, your brain probably goes more to “cookies and milk” than “DEC and Ikea” but after watching [Dave]’s latest on Usagi Electric where he puts a PDP-11 into an Ikea desk, you may rethink that.

The PDP-11 is vintage hardware that actually lived inside of a different desk, once upon a time, serving as the control unit for an FTIR spectrometer. While the lab equipment has thankfully survived the decades, the desk did not and when [Dave] got the unit it was as a pile of parts. He revived it, of course– it’s kind of what he does– but it didn’t get a new desk for years, until his latest shop re-organization.

The one concession to modernity– and missing parts– is using switching power supplies rather than the bulky linear PSU that would have originally powered the unit. It’s a good thing, too, or we have trouble picturing how everything would fit! This particular PDP-11 comes with the high performance vector processing unit in order to crunch those spectrographs, and apparently those chips idle at about 60C, so the desk-case got some decent-sized 120V fans to keep everything cool and running for years to come.

This isn’t the most aesthetic or fanciest case-mod we’ve seen, mostly being made of surplus plywood and scrap metal fittings, but it certainly gets the job done. Given that the PDP-11 has been crammed into every form-factor known to man, from a system-on-a-chip (before anybody really talked about SOCs) to desktop workstations, and of course the hulking cabinets with their iconic blinkenlights-– it’s hard to say that this installation isn’t reasonably authentic, even if it isn’t the original desk.

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See The Computers That Powered The Voyager Space Program

March 30, 2026 by Julian Scheffers 11 Comments

Have you ever wanted to see the computers behind the first (and for now only) man-made objects to leave the heliosphere? [Gary Friedman] shows us, with an archived tour of JPL building 230 in the ’80s.

A NASA employee picks up a camcorder and decides to record a tour of the place “before they replace it all with mainframes”. They show us computers that would seem prehistoric compared to anything modern; early Univac and IBM machines whose power is outmatched today by even an ESP32, yet made the Voyager program possible all the way back in 1977. There are countless peripherals to see, from punch card writers to Univac debug panels where you can see the registers, and from impressive cabinets full of computing hardware to the zip-tied hacks “attaching” a small box they call the “NIU”, dangling off the inner wall of the cabinet. And don’t forget the tape drives that are as tall as a refrigerator!

We could go on ad nauseum, nerding out about the computing history, but why don’t you see it for yourself in the video after the break?

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