2026-04-04 13:00:52
The Allen Scythe is one of those fantastic pieces of vintage agricultural machinery which would never be allowed to be manufactured today for health and safety reasons. It’s a two-wheel walk-behind device with a frightening reciprocating cutter bar which makes short work of almost anything. It’s the perfect tool for the roughest of brush clearance, but it demands respect. [Way Out West Workshop Stuff] has one, and is replacing the vintage Villiers two-stroke engine with an electric motor.
The conversion is straightforward enough, the Villiers crankshaft being replaced with a straight-through axle that can be driven by the motor. We particularly like the use of a cable tie as a splash lubricator. The shaft is turned to accept the Villiers’ bearings, the gear to drive the Allen, and a chain sprocket where the cord start would go on the engine. A mounting plate puts the motor above, a chain is fitted, and it’s ready to go once a hefty battery pack has been installed.
There are two videos below the break, showing construction, and finally the machine in action. The electric Allen is every bit as useful as the original, without the noise and vibration. Villiers motors can be temperamental, so we’d view it as an upgrade worth having.
2026-04-04 10:00:41
In this wonderful world of MEMS technology, sensor technology has been downsized and reduced in cost to the point where you can buy a car tire pressure sensor for less than $3 USD on a site like AliExpress. Recently [electronupdate] got his mittens on one of these items to take a look inside, and compare it against his trusty old mechanical tire pressure gauge.
Perhaps unsurprisingly, there isn’t a whole lot inside these devices once you pop them open to reveal the PCB. The MEMS device is a tiny device at the top, which has the pressurized air from the tire guided to it. The small hole inside the metal can leads to the internals that consist of a thin diaphragm with four piezoresistors that enable measurements on said diaphragm from which pressure can be determined.
Handling these measurements and displaying results on the small zebra connector-connected LCD is an 8-bit MCU manufactured by Chinese company SDIC. Although the part number on the die doesn’t lead to any specific part on the SDIC site, similar SDIC parts have about 256 bytes of SRAM and a few kB of one-time programmable ROM.
This MCU also integrates the clock oscillator, thus requiring virtually no external parts to work. Finally, its sigma-delta ADC interacts with the MEMS device, rounding out a very simple device that’s nevertheless more than accurate enough for a spot check as well as quite portable.
2026-04-04 07:00:19
Today, fireplaces, their cozy glow once a household staple, are mostly a thing of the past. In fact, a decent amount of old fireplaces are completely blocked up! [David Capper] brings back the atmosphere without the actual flames, with his RP2040-based fireplace glow simulator.
It’s not just a string of LEDs with some PWM brightness control, either. No, [David] goes into detail about the black body radiation that gives these fires their colors. He then uses the theory of black-body radiation to determine the colors that the LEDs glow to simulate the colors of a real fire.
But the colors alone don’t make for a good simulated fire, so [David] adds the heat equation. It starts with a grid wherein each cell has a temperature. Over time, cells are randomly selected to have heat added to them (increasing the cell’s temperature), then he applies the heat equation to diffuse and decay the heat within the grid for a nice simulated crackling fire. Add in a custom PCB and a nice little 3D-printed case and you’re ready for a cozy hacker time.
2026-04-04 04:00:18
Before there was pressure-treated wood, before modern paints, there was pine tar. Everything from tool handles to wagons to ships were made of wood preserved with pine tar, once upon a time, and [woodbrew] wants to show you how to make it, how to use it, and why you might put it on your skin.
It starts with, you guessed it, pine! In the first part of the video, [woodbrew] creates a skin salve with pine resin and food-safe oil. The pine resin–which is the sticky goop that dries around wounds on evergreen trees–is highly antiseptic and has been used in wound salves since the stone age. The process is easy: melt it in a double boiler, then mix with equal parts oil. [woodbrew] also adds a touch of beeswax to firm it up, an a little eucalyptus extract for extra germ-killing power, and a nice smell to boot.
That’ll preserve your hands, but what about preserving wood? That starts at about 9 minutes in, and for that you’re going to need a lot more resin, so picking it off wounded trees like he does at the start of the video won’t work. [woodbrew] suggests starting with dead-or-dying pines, and harvesting the crooks of their branches for “fatwood” — wood with the highest resin content. He also suggests the center of stumps, again of trees that died or were severely injured before being cut down. Then it’s a matter of cooking those fine organic molecules out. This is where we burn the wood to save the wood. Well, to save other wood. Wood we didn’t burn, obviously.
The distillation process [woodbrew] uses it fairly traditional, and consists of a couple of buckets. One bucket is buried and collects the pine tar; the other, with holes in the bottom to allow the tar to drip out, is filled with fatwood and covered tightly before being surrounded by firewood which is set alight. You could use an alternate source of heat here, but if you just cut down a pine tree for its fatwood, well, you’d have the rest of the tree to work with. Inside the fatwood bucket, the heat of the fire cooks off the volatile compounds that make pine tar, while the lack of oxygen from being closed up keeps it from burning. Burying the collection bucket keeps it from getting so hot the volatiles all boil off.
If this sounds like the process for making charcoal or woodgas, that’s because it is! He’s letting the gas fraction flare off here, but you could probably capture it– though a true gasifier brakes the tar down into gaseous compounds as well. The charcoal of course stays in the bucket as a bonus.
To make it usable as a wood finish, [woodbrew] mixes his homemade pine tar 50:50 with linseed oil, thining it to a spreadable consistency that helps it penetrate deep into the wood. By filling the voids in the wood, this mixture will help keep moisture out, and the antiseptic properties of the organic soup that is pine tar will help keep fungi at bay for potentially decades to come.
Thanks to [Keith Olson] for the tip!
2026-04-04 02:30:58
The Sinclair ZX81 was hardly the most accomplished of 1980s 8-bit microcomputers, but its ultra-low-budget hardware was certainly pressed into service for some impressive work. Perhaps the most legendary piece of commercial software in this vein was 1K Chess, which packed an entire chess engine into the user-available bytes in the unexpanded 1K ZX’s memory map. [MarquisdeGeek] has taken this vintage piece of code in 2026 and subjected it to a thorough analysis, finding all the tricks along the way.
Though hackers have since found ways to trick the ’81 into displaying bitmap graphics, using it as intended is text-only with some limited block graphics. The chess board then is text-only, and its illusion of “thinking” about moves comes courtesy of the on-screen board doubling as the play area memory. In the GitHub repository you can find decompiled and annotated versions as well as the original ZX binary, with as a bonus a screen capture of the game as it appears as BASIC with the ZX’s odd means of storing Z80 code in REM statements.
If that wasn’t enough, in his note giving us the tip he reveals that much of the work was done in a ZX emulator running in a Dragon emulator, and gives us a fun glimpse of the game running in an emulator on a Cheap Yellow Display inside 1K Chess cassette box. We like it, a lot!
If you need a greater ZX81 fix, take a look at how this machine chased the beam to make TV graphics on the cheap.
2026-04-04 00:00:18
This week, Hackaday’s Elliot Williams and Kristina Panos met up over assorted beverages to bring you the latest news, mystery sound results show, and of course, a big bunch of hacks from the previous seven days or so.
In the news, there’s quite a bit to talk about. Regarding Hackaday Europe, you can rest assured that the talks will be announced soon. The Green-Powered Challenge is still underway, and we need your entry to truly make it a contest. You have until April 24th to enter, so show us what you can do with power you scrounge up from the environment!
As usual, we published a handful of April Fool’s posts, which you may or may not find amusing. And finally — no fooling — our own Tom Nardi wrote up the Artemis moon launch, and is going to update the post every day until the mission ends.
On What’s That Sound, we can score one for Kristina, which brings her record to approximately three wins and sixty-eight losses. She knew without a doubt that the dialogue was from the Day the Earth Stood Still (1951). Oh, what? There was a remake in 2008? Kristina should get bonus points, then.
After that, it’s on to the hacks, beginning with the basics of making clean enclosures that are decidedly not 3D-printed, a couple of sweet lo-fi cameras, and a nice way to tame the tape when it comes to SMT parts. We also discuss a clock that marks time in a mathematical way, watch an electro-permanent magnet in action, and improving soda by turning it into mead. Finally, we discuss the solar balconies taking Europe by storm, and Copilot’s terrifying terms of service.
Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
Download in DRM-free MP3 and savor at your leisure.
