When you think of ethanol, you might think of it as a type of alcohol, not alcohol itself. However, in reality, it is the primary ingredient in adult beverages. Which means humans have gotten quite good at making it, as we’ve been doing for a long time. With this in mind, [Sam Barker] decided to make ethanol out of apples to power a small engine to charge his phone.
The steps for making pure ethanol is quite similar to making alcoholic cider. A friend of [Sam’s] had an orchard and a surplus of apples, so [Sam] boiled them down and stored the mush in jugs. He added activated dry yeast to start the fermentation process. A dry lock allowed the CO2 gas that was being created to escape. Over a few weeks, the yeast converted all the sugar into ethanol and gas. In the meantime, [Sam] sourced a chainsaw and adapted the engine to run on ethanol, as ethanol needs to run richer than gasoline. The video below the break tells the story.
[Breaking Taps] has a nice pulsed fiber laser and decided to try it to micromachine with silicon. You can see the results in the video below. Silicon absorbs the IR of the laser well, although the physical properties of silicon leave something to be desired. He also is still refining the process for steel, copper, and brass which might be a bit more practical.
The laser has very short duration pulses, but the pulses have a great deal of energy. This was experimental so some of the tests didn’t work very well, but some — like the gears — look great.
The basic idea is to mount the display over the potentiometer knob so you can show useful information such a label that shows what it does, and a readout of the currently detected value. But you’ll likely want to show where the knob is currently set within the range of possible values as well, and that’s where things get interesting.
In the video after the break, [upir] spends a considerable amount of time explaining the math behind details like the scrolling tick marks. The nearly 45 minute long video wraps up with some optimization, as getting the display to move along with the knob in real-time on an Arduino UNO took a bit of extra effort. The final result looks great, and promises to be a relatively cheap way to add an elegant and functional bit of flair to an otherwise basic knob.
On the shortlist of workshop luxuries, we’d bet a lot of hackers would include an overhead crane. Having the ability to lift heavy loads safely and easily opens up a world of new projects, and puts the shop into an entirely different class of capabilities.
As with many of us, [Jornt] works in a shop with significant space constraints, so the jib crane he built had to be a custom job. Fabricated completely from steel tube, the build started with fabricating a mast to support the crane and squeezing it into a small slot in some existing shelves in the shop, which somehow didn’t catch on fire despite being welded in situ. A lot of custom parts went into the slewing gear that mounts the jib, itself a stick-built space frame that had to accommodate a pitched ceiling. A double row of tubing along the bottom of the jib allows a trolley carrying a 500 kg electric winch to run along it, providing a work envelope that looks like it covers the majority of the shop. And hats off for the safety yellow and black paint job — very industrial.
From the look of the tests in the video below, the crane is more than up to the task of lifting engines and other heavy loads in the shop. That should prove handy if [Jornt] tackles another build like his no-compromises DIY lathe again.
When it comes to sci-fi, it’s hard to go past Star Wars, and many submissions to our contest land in that exact universe. [Kevin Harrington]’s entry is one such example, with his animatronic Baby Yoda that’s exactly as cute as you’d hope it would be.
The build is based on a Pololu Romi chassis, a simple two-wheeled differential-drive robot platform. It’s paired with a robot arm in the form of Hephaestus Arm 2, which provides the articulation for the precocious little creature. An ESP32 microcontroller serves as the brains of the operation, controlling all the servos and motors that make baby Yoda move. Control is via WiFi, using a website hosted on the ESP32 via RBE1001lib.
The animatronic baby Yoda would surely be a hit sitting on one’s shoulder at any sci-fi convention. Overall, it’s a simple robot that becomes more personable by skinning it with an adorable toy. It’s not the first baby Yoda (or Grogu) that we’ve seen, either – the popular character has inspired builds before, too! Video after the break.
Yeah, I’ll admit it: I’m a Windows person. Two years ago this summer, I traded in an overworked Windows 7 laptop that was literally screaming in pain for a SFF Windows 10 box as my main machine. But 10 might mean the end for this scribe, who has used Windows since the late 1980s. Admittedly, it’s for a fairly petty reason — Microsoft have gotten rid of alternate-location taskbar support in Windows 11. As in, you can have the taskbar anywhere you want, as long as it’s the bottom of the screen.
Years ago, I switched my taskbar to the top for various reasons. For one, it just made more sense to me to have everything at the top, and nothing at the bottom to interrupt visual flow while reading a web page or a document. Plenty of people move it to one of the sides or hide it when not in use for the same reason. More importantly, I thought moving the taskbar to the top would help with my neck/shoulder strain issues, and I believe that it has. So oddly enough, this one little thing may be the dealbreaker that gets me to switch after thirty-something years to Linux, where top-aligned taskbars are more or less the norm.
A line follower is a common project for anyone wishing to make a start in robotics, a small wheeled device usually with some kind of optical sensor which allows it to follow a line drawn on the surface over which it runs. In most cases they incorporate a small microcontroller or perhaps an analogue computer which supplies power and steering control, but as the Crayon Car from [Greg Zumwalt] demonstrates, it’s possible to make a line follower without any brains at all.
This seemingly impossible feat is achieved thanks to the line and road surface, it runs on a piece of paper over which the line is drawn with a crayon. The robot has a single straight-line drive wheel at one end and a pair of driven rollers at 90 degrees to each other at the other end, with the magic happening due to the difference in friction between paper and crayon. The robot follows a circular track with no problem, and while we can see it’s not without flaws we doubt it would be possible to make a simpler follower.