Bruteforcing Accidental Antenna Designs

February 17, 2026 by Zoe Skyforest 20 Comments

Antenna design is often referred to as a black art or witchcraft, even by those experienced in the space. To that end, [Janne] wondered—could years of honed skill be replaced by bruteforcing the problem with the aid of some GPUs? Iterative experiments ensued.

[Janne]’s experience in antenna design was virtually non-existent prior to starting, having a VNA on hand but no other knowledge of the craft. Formerly, this was worked around by simply copying vendor reference designs when putting antennas on PCBs. However, knowing that sometimes a need for something specific arises, they wanted a tool that could help in these regards.

The root of the project came from a research paper using an FDTD tool running on GPUs to inversely design photonic nanostructures. Since light is just another form of radio frequency energy, [Janne] realized this could be tweaked into service as an RF antenna design tool. The core simulation engine of the FDTD tool, along with its gradient solver, were hammered into working as an antenna simulator, with [Janne] using LLMs to also tack on a validation system using openEMS, an open-source electromagnetic field solver. The aim was to ensure the results had some validity to real-world physics, particularly important given [Janne] left most of the coding up to large language models. A reward function development system was then implemented to create antenna designs, rank them on fitness, and then iterate further.

The designs produced by this arcane system are… a little odd, and perhaps not what a human might have created. They also didn’t particularly impress in the performance stakes when [Janne] produced a few on real PCBs. However, they do more-or-less line up with their predicted modelled performance, which was promising. Code is on Github if you want to dive into experimenting yourself. Experienced hands may like to explore the nitty gritty details to see if the LLMs got the basics right.

We’ve featured similar “evolutionary” techniques before, including one project that aimed to develop a radio. If you’ve found ways to creatively generate functional hardware from boatloads of mathematics, be sure to let us know on the tipsline!

3D Printed Jack Mixes Two Filaments For Great Performance

February 17, 2026 by Zoe Skyforest 12 Comments

If you’re looking to jack up your car and you don’t have anything on hand, your 3D printer might not be the first tool you look towards. With that said, [Alan Reiner] had great success with a simple idea to create a surprisingly capable scissor jack with a multi-material print.

The design will look familiar if you’ve ever pulled the standard jack out of the back of your car. However, this one isn’t made fully out of steel. It relies on an M6 bolt and a rivet nut, but everything else is pure plastic. In this scissor jack design, rigid PETG arms are held in a scissor jack shape with a flexible TPU outer layer. Combined with the screw mechanism, it’s capable of delivering up to 400 pounds of force without failing. It’s an impressive figure for something made out of 80 grams of plastic. The idea came about because of [Alan’s] recent build of a RatRig VCore4 printer, which has independent dual extruders. This allowed the creation of single prints with both rigid and flexible filaments included.

[Alan] did test the jack by lifting up his vehicle, which it kind of achieved. The biggest problem was the short stroke length, which meant it could only raise the back of the car by a couple inches. Printing a larger version could make it a lot more practical for actual use… if you’re willing to trust a 3D-printed device in such use.

Files are on Printables if you wish to make your own. It’s worth paying attention to the warning upfront that [Alan] provides—”THIS CAN CREATE A LOT OF FORCE (400+ lbs!), WHICH MEANS IT CAN STORE A LOT OF ENERGY THAT MIGHT BE RELEASED SUDDENLY. Please be cautious using 3d-printed objects for high loads and wear appropriate safety equipment!”

Funnily enough, we’ve featured 3D printed jacks before, all the way back in 2015! Video after the break.

Continue reading “3D Printed Jack Mixes Two Filaments For Great Performance” →

LEGO Orrery Gets A Real-Time Drive Upgrade

February 17, 2026 by Zoe Skyforest 4 Comments

An orrery is a beautiful type of mechanical contrivance, built to demonstrate the motion of heavenly objects. LEGO happens to offer just such a device, built using its Technic line of blocks, shafts, and gears. Only, it has a serious limitation—it has to be cranked manually to make it spin the Earth around the sun. [Görkem] set out to fix this glaring oversight with some good old-fashioned hardware.

The setup removes just five LEGO pieces from the original design, eliminating the hand crank from the mechanism. In its place, [Görkem] installed a NEMA 17 stepper motor, paired with a custom PCB mounted on the back. That carries an ESP32 microcontroller and a TMC2208 stepper motor driver set up for silent drive. Rigged up like so, the orrery can simulate the motion of the Earth and Moon around the Sun in real time. There’s also a knob to track back and forth in time, and a button to reset the system to the correct real-time position.

The final build looks great, combining the LEGO Technic parts with some chunky electronics and 7-segment displays that make it a wonderful techy desk decoration. Down the line, [Görkem] hopes to offer a plug-and-play kit to others who wish to duly animate their own LEGO orrery sets (set #42179).

We love a good LEGO build around these parts. We’ve featured everything from parts sorters to functional typewriters in the past.

Continue reading “LEGO Orrery Gets A Real-Time Drive Upgrade” →

A Basic Guide To Shielding

February 16, 2026 by Zoe Skyforest 6 Comments

[GreatScott] has recently been tinkering in the world of radio frequency emissions, going so far as to put their own designs in a proper test chamber to determine whether they meet contemporary standards for noise output. This led them to explore the concept of shielding, and how a bit of well-placed metal can make all the difference in this regard.

The video focuses on three common types of shielding—absorber sheets, shielding tapes, and shielding cabinets. A wide variety of electronic devices use one or more of these types of shielding. [GreatScott] shows off their basic effectiveness by putting various types of shielding in between a noise source and a near-field probe hooked up to a receiver. Just placing a bit of conductive material in between the two can cut down on noise significantly. Then, a software defined radio (SDR) was busted out for some more serious analysis. [GreatScott] shows how Faraday cages (or simple shielding cabinets] can be used to crush down spurious RF outputs to almost nothing, and how his noisy buck-boost designs can be quieted down with the use of the right absorber sheets that deal well with the problematic frequencies in question. The ultimate upshot of the tests is that higher frequencies respond best to conductive shielding that is well enclosed, while lower frequency noise benefits from more absorptive shielding materials with the right permeability for the job.

Shielding design can be a complex topic that you probably won’t master in a ten minute YouTube video, but this content is a great primer if you’re new to the topic. We’ve covered the topic before, too, particularly on how a bit of DIY shielding can really aid a cheap SDR’s performance. Video after the break.

Continue reading “A Basic Guide To Shielding” →

Real LED TVs Are Finally Becoming A Thing

February 16, 2026 by Zoe Skyforest 58 Comments

Once upon a time, the cathode ray tube was pretty much the only type of display you’d find in a consumer television. As the analog broadcast world shifted to digital, we saw the rise of plasma displays and LCDs, which offered greater resolution and much slimmer packaging. Then there was the so-called LED TV, confusingly named—for it was merely an LCD display with an LED backlight. The LEDs were merely lamps, with the liquid crystal doing all the work of displaying an image.

Today, however, we are seeing the rise of true LED displays. Sadly, decades of confusing marketing messages have polluted the terminology, making it a confusing space for the modern television enthusiast. Today, we’ll explore how these displays work and disambiguate what they’re being called in the marketplace.

Continue reading “Real LED TVs Are Finally Becoming A Thing” →

Converting AC Irrigation Valves To DC Operation

February 9, 2026 by Zoe Skyforest 34 Comments

Due to historical engineering decisions made many decades ago, a great many irrigation systems rely on solenoid valves that operate on 24 volts AC. This can be inconvenient if you’re trying to integrate those valves with a modern smart home control system. [Johan] had read that there were ways to convert these valves to more convenient DC operation, and dived into the task himself.

As [Johan] found, simply wiring these valves up to DC voltage doesn’t go well. You tend to have to lower the voltage to avoid overheating, since the inductance effect used to limit the AC current doesn’t work at DC. However, even at as low as 12 volts, you might still overheat the solenoids, or you might not have enough current to activate the solenoid properly.

The workaround involves wiring up a current limiting resistor with a large capacitor in parallel. When firing 12 volts down the line to a solenoid valve, the resistor acts as a current limiter, while the parallel cap is initially a short circuit. This allows a high current initially, that slowly tails off to the limited value as the capacitor reaches full charge. This ensures the solenoid valve switches hard as required, but keeps the current level lower over the long term to avoid overheating. According to [Johan], this allows running 24V AC solenoid valves with a 12V DC supply and some simple off-the-shelf relay boards.

We’ve seen similar work before, which was applied to great effect. Sometimes doing a little hack work on your own can net you great hardware to work with. If you’ve found your own way to irrigate your garden as cheaply and effectively as possible, don’t hesitate to notify the tipsline!

Habit Detection For Home Assistant

February 8, 2026 by Zoe Skyforest 15 Comments

Computers are very good at doing exactly what they’re told. They’re still not very good at coming up with helpful suggestions of their own. They’re very much more about following instructions than using intuition; we still don’t have a digital version of Jeeves to aid our bumbling Wooster selves. [Sherrin] has developed something a little bit intelligent, though, in the form of a habit detector for use with Home Assistant.

In [Sherrin]’s smart home setup, there are lots of things that they wanted to fully automate, but they never got around to implementing proper automations in Home Assistant. Their wife also wanted to automate things without having to get into writing YAML directly. Thus, they implemented a sidecar which watches the actions taken in Home Assistant.

The resulting tool is named TaraHome. When it detects repetitive actions that happen with a certain regularity, it pops up and suggests automating the task. For example, if it detects lights always being dimmed when media is playing, or doors always being locked at night, it will ask if that task should be set to happen automatically and can whip up YAML to suit. The system is hosted on the local Home Assistant instance. It can be paired with an LLM to handle more complicated automations or specific requests, though this does require inviting cloud services into the equation.

We’ve featured lots of great Home Assistant hacks over the years, like this project that bridges 433 MHz gear to the smart home system. If you’ve found your own ways to make your DIY smart home more intelligent, don’t hesitate to notify the tipsline!