2026-02-19 00:30:36
Despite the best efforts of the manufacturers, there are folks out there that try to repair power tools, with [Dean Doherty] being one of them. Recently he got a Milwaukee M18 cordless planer in for repairs, which started off with just replacing some dodgy bearings, but ended up with diagnosing a faulty controller. Consequently the total repair costs went up from reasonable to absolutely unreasonable, leading to a rant on why Milwaukee tools are terrible to repair.
Among the symptoms was the deep-discharged battery, which had just a hair over 7 V while unloaded. Question was what had drained the battery so severely. What was clear was that the tool was completely seized after inserting a working battery with just a sad high-pitched whine from a stalled motor.
After replacing both bearings and grumbling about cheap bearings, the tool had a lot of drywall dust cleaned out and was reassembled for a test run. This sadly showed that the controller board had been destroyed due to the seized rotor bearing, explaining the drained battery. Replacing the controller would have cost €60-70 as it comes with the entire handle assembly, rendering the repair non-viable and a waste.
Perhaps the one lesson from this story is that you may as well preventively swap the cheap bearings in your Milwaukee tools, to prevent seizing and taking out the controller board. That said, we’d love to see an autopsy on this controller board fault.
Thanks to [paulvdh] for the tip.
2026-02-18 23:00:54
Today, we take ice for granted. But having ice produced in your home is a relatively modern luxury. As early as 1750 BC, ancient people would find ice on mountains or in cold areas and would harvest it. They’d store it, often underground, with as much insulation as they could produce given their level of technology.
The key to Persian icemaking was yakhchāls. Not all of them were the same, but they typically consisted of an underground pit with a conical chimney structure. In addition, they often had shade walls and ice pits as well as access to a water supply.
The conical shape optimizes the solar chimney effect, where the sun heats air, which then rises. The top was typically not open, although there is some thought that translucent marble may have plugged the top to admit light while blocking airflow. yakhchālThe solar chimney produces an updraft that tends to cool the interior. The underground portion of the yakhchāl has colder air, as any hot air rises above the surface.
The structure uses a water-resistant mortar made of sand, clay, egg whites, lime, goat hair, and ash. This has good insulating properties, although how the Persians found this recipe is a mystery. Many also had windcatcher towers that allowed for evaporative cooling in the dry air.
Adjacent to the yakhchāl was often a shallow ice pool protected by a shade wall to block the sun. The shade wall minimized heating from the sun. Just as the Egyptians leveraged evaporative and radiative cooling to create ice, cold nights could produce ice in the pool, which workers would harvest and store inside the yakhchāl. They could also, of course, store ice harvested from elsewhere. Even with the shade wall, though, workers had to harvest ice before sunrise.
You could think of the whole system as an RC circuit. The dome and the soil around the pit form a resistance, while the ice, cold stone, and air inside form a thermal capacitor. Thick insulating walls make a large R, and tons of ice and stone make a big capacitor. The dome shape gets less solar radiation most of the time. With a big resistor and capacitor, bleeding off charge (in this case, leaking in heat) takes a long time.
Meanwhile, ice melting effectively absorbs leftover or leaking heat. Sure, you lose some ice, although with the ice pits, on a cold and dry night, you might be able to recover at least some of it.
The Persians wanted ice for the same reasons everyone else did. They preserved food, created frozen beverages (sharbat), and even a dessert, faloodeh, that combined noodles, rose syrup, lime, and ice. There were also medical uses. Of course, having ice in the hot desert was also a status symbol.
In China, around 600 AD, they used saltpeter to produce ice chemically instead of simply harvesting and storing it. It would be 1748 before [William Cullen] would demonstrate producing ice using artificial means. While [Oliver Evans] described a fairly modern refrigerator in 1805, nothing like it was built until [Jacob Perkins] did it in 1834. Australian [James Harrison] was probably the first commercial ice makaer in the mid 1800s.
These days, we don’t usually ship ice around, but we still have to ship cold things. And of course, refrigerators ended the ice harvesting business.
Featured image: “kosar” by [Elyaskb]
2026-02-18 20:00:55
When World of Warcraft was launched in 2004, it became somewhat of a juggernaut in the MMORPG space. Millions of players continue to login every month. [Kelsi Davis] is one such player, but she doesn’t always log in with the regular client anymore. That’s because she put together WoWee—an open-source alternative of her very own.
WoWee is an acronym—World of Warcraft Engine Experiment. Coded in native C++, it’s a homebrewed client that uses a custom OpenGL renderer to display the game world. [Kelsi] notes that it’s strictly an “educational/research” project, built without using any official Blizzard assets, data or code. Instead, it grabs some client data from a legally-obtained install to operate and loads certain assets this way.
It’s currently compatible with the vanilla game as well as The Burning Crusade and Wrath of the Lich King expansions. It should be highlighted how much work this project has already involved—with [Kelsi] needing to recreate various functional minutae in the game, from character creation screens to weather systems and skyboxes. There’s still a lot to do, as well, like adding 3D audio support and making it more interoperable with the quest system.
It’s rare that any MMO gets an open-source client, even less so while the original game is still being actively supported by the developers. Still, we do see some creative hacks in this space.
2026-02-18 17:00:20
The Raspberry Pi has brought digital camera experimentation within the reach of everybody, with its combination of an accessible computing platform and some almost-decent camera sensors. If there’s a flaw in the Pi as a camera though, it lies in the software, which can be slow and frustrating to use. [Martijn Braam] is here with an interesting project that might yield some useful results in this direction, he’s making a Raspberry Pi studio camera.
His camera hardware is very straightforward, a Pi 5 and touchscreen with the HD camera module in a rough but serviceable wooden box. The interesting part comes in the software, in which he’s written a low-latency GUI over an HDMI output camera application. It’s designed to plug into video mixing hardware, and one of the HDMI outputs carries the GUI while the other carries the unadulterated video. We can see this used to great effect with for example OBS Studio. It’s for now a work in progress as you can see in the video below the break, but we expect that it can only get better.
The video below exposes the obvious flaw in many Pi camera setups, that the available lenses don’t match the quality of the sensor, in that good glass ain’t cheap. But we think it’s one to watch, and could provide competition for CinePi.
2026-02-18 14:00:20
Making your own laptop can be a challenging project, but a doable one, especially given the large number of options available today for computing. Of course nothing says you need to use a modern component in your build, and in the LT6502 project by [TechPaula] they didn’t go with a modern RPi or the like, nope went right back to about 50 years ago to use a 6502 at the heart of this DIY laptop build.
The 6502 is an 8-bit microprocessor from the 1970s, found in the Commodore 64 and Apple II. This wasn’t their first venture into 8 MHz world of the 6502, prior to this laptop build there was a desktop build the PC6502 bringing this chip of old into a PC/104 form factor. The LT6502 adds in the things you’d expect with a laptop, a 9-inch foldable screen, a 10,000 mAh battery, several external ports for things such as serial console and USB-C charging. A custom keyboard adds in low-profile switches as well as including a HDSP-style 8-character display, a great addition for a modern take on this vintage chip. Onboard there is 46 KB of RAM and with the addition of the CompactFlash for storage the LT6502 runs EhBASIC which we’ve seen before in some other great projects.
The case is mainly 3D-printed safely enclosing the custom PCBs for both the keyboard and motherboard, and providing a satisfying glow with the built-in LEDs within. All of the files are up on the project’s site so be sure to swing by and check out both this and the desktop PC/104 predecessor to it. Great job [TechPaula], looking forward to seeing the future installments on the LT6502 such as implementing the included internal expansion slot.
2026-02-18 11:00:45
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!
