2026-02-06 23:00:56
When it comes to seaborne propulsion, one simple layout has largely dominated over all others. You pair some kind of engine with some kind of basic propeller at the back of the ship, and then you throw on a rudder to handle the steering. This lets you push the ship forward, left, and right, and stopping is just a matter of turning the engine off and waiting… or reversing thrust if you’re really eager to slow down.
This basic system works for a grand majority of vessels out on the water. However, there is a more advanced design that offers not only forward propulsion, but also steering, all in the one package. It may look strange, but the Voith Schneider propeller offers some interesting benefits to watercraft looking for an edge in maneuverability.
The Voith Schneider propeller design looks rather unlike any propeller you might have seen before. Perhaps the most obvious reason is because of its axis of operation. Traditional propellers tend to operate in an axis parallel with the waterline, or at least within a few degrees or so. However, the Voith Schneider design spins about the vertical axis instead. This is because it uses vertically-oriented blades mounted on a rotating plate. Each blade has a hydrofoil profile, which enables it to generate thrust when moving through the water. By spinning these blades at speed and varying their angle of attack, it’s possible to create a thrust vector in any direction on the horizontal plane. A special gear system is used to vary the angle of each blade as the plate rotates, such that the overall net thrust generated by all the blades is in the desired direction of travel.
This design has certain key advantages over a traditional maritime propulsion setup. Namely, by fitting a vessel with Voith-Schneider propellers, it’s possible to add a great deal of maneuverability, to the point where a traditional rudder becomes entirely unnecessary. Instead of having to thrust the ship forwards and then turn, it’s possible to directly push the vessel with each individual thruster in the direction that is desired. This can be particularly useful for low-speed operations like docking, and provides a much more instantaneous change of direction than is possible with a regular propeller and rudder setup.
Voith Schneider thrusters are particularly useful for ships like tugs where precision maneuverability is a huge aid to operations. Numerous thrusters are often to a given vessel, providing greater total thrust and additional control. It’s also typical to fit Voith Schneider propellers with a guard underneath, which prevents grounding damage and can act as a sort of nozzle that improves low-speed performance. These propellers are perhaps not the ideal choice for watercraft aiming for outright speed, but for lower-speed work, they can offer great benefits in control.
The design looks somewhat unintuitive and even futuristic, but it actually goes back a long way. The first prototype was actually designed as a water turbine for generating electricity. However, it proved unexceptional in this role. It was only when the device was tested as a pump that engineers realized it could be repurposed as a combined thruster to replace a traditional propeller and rudder. A patent was issued in Germany in 1972, and the first prototype was tested on the water all the way back in 1928, on a small 60-horsepower vessel known as the Torqueo. The design soon found use on a number of German vessels in the interwar period, including minesweepers. The Voith Schneider design can be operated quite slowly while still providing thrust, minimizing cavitation and thus sound signature, which is considered advantageous for this role. In some German designs, such as the failed Graf Zeppelin aircraft carrier, the thrusters were even installed alongside regular propulsion systems, and made retractable so they wouldn’t present additional drag when not in use. Some decades later, the US Navy itself would later field similarly-equipped minesweepers in the 1990s, though all examples were dismantled and sold off by the early 2000s. Beyond military uses, the thruster has found application in a number of ferries and tugs around the world, and remain in production today.
Despite their unique abilities, Voith Schneider propellers remain a curio rather than a fixture in the shipping world. In the past century of their existence, just 4,500 examples have been built, near exclusively by Voith AG, and thus they are equipping a relatively small amount of the global maritime fleet. They compete with more familiar designs, such as azimuth thrusters, which are widely popular and more intuitive to understand. Given their oddball nature, and moderate level of mechanical complexity, they’re perhaps never going to supplant the tried-and-true prop and rudder that propels most conventional vessels. Still, if you’re looking to build a ship that can elegantly strafe in any direction you want to go, it’s hard to go past the Voith Schneider concept for all the benefits it brings.
2026-02-06 20:00:01
Much like how BusyBox crams many standard Unix commands and a shell into a single executable, so too does BreezyBox provide a similar experience for the ESP32 platform. A demo implementation is also provided, which uses the ESP32-S3 platform as part of the Waveshare 7″ display development board.
Although it invokes the BusyBox name, it’s not meant to be as stand-alone as it uses the standard features provided by the FreeRTOS-based ESP-IDF SDK. In addition to the features provided by ESP-IDF it adds things like a basic virtual terminal, current working directory (CWD) tracking and a gaggle of Unix-style commands, as well as an app installer.
The existing ELF binary loader for the ESP32 is used to run executables either from a local path or a remote one, a local HTTP server is provided and you even get ANSI color support. Some BreezyBox apps can be found here, with them often running on a POSIX-compatible system as well. This includes the xcc700 self-hosted C compiler.
You can get the MIT-licensed code either from the above GitHub project link or install it from the Espressif Component Registry if that’s more your thing.
2026-02-06 17:00:05
Have you ever dreamed of making a bash script that assembles Intel 8080 machine code? [Chris Smith] did exactly that when he created xa.sh, a cross-assembler written entirely in Bourne shell script.
The script exists in part as a celebration of the power inherent in a standard Unix shell with quite ordinary POSIX-compliant command line tools like awk, sed, and printf. But [Chris] admits that mostly he found the whole project amusing.
It’s designed in a way that adding support for 6502 and 6809 machine code would be easy, assuming 8080 support isn’t already funny enough on its own.
It’s not particularly efficient and it’s got some quirks, most of which involve syntax handling (hexadecimal notation should stick to 0 or 0x prefixes instead of $ to avoid shell misinterpretations) but it works.
Want to give it a try? It’s a shell script, so pull a copy and and just make it executable. As long as the usual command-line tools exist (meaning your system is from sometime in the last thirty-odd years), it should run just fine as-is.
An ambitious bash script like this one recalls how our own Al Williams shared ways to make better bash scripts by treating it just a bit more like the full-blown programming language it qualifies as.
2026-02-06 14:00:28
The Commodore Amiga was famous for its characteristic Say voice, with its robotic enunciation being somewhat emblematic of the 16-bit era. The Commodore VIC-20 had no such capability out of the box, but [Mike] was able to get one talking with a little bit of work.
The project centers around the Adventureland cartridge, created by Scott Adams (but not the one you’re thinking of). It was a simple game that was able to deliver speech with the aid of the Votrax Type and Talk speech synthesizer box. Those aren’t exactly easy to come by, so [Mike] set about creating a modern equivalent. The concept was simple enough. An Arduino would be used to act as a go between the VIC-20’s slow serial port operating at 300 bps and the Speakjet and TTS256 chips which both preferred to talk at 9600 bps. The audio output of the Speakjet is then passed to an LM386 op-amp, set up as an amplifier to drive a small speaker. The lashed-together TTS system basically just reads out the text from the Adventureland game in an incredibly robotic voice. It’s relatively hard to understand and has poor cadence, but it does work – in much the same way as the original Type and Talk setup would have back in the day!
Text to speech tools have come a long way since the 1980s, particularly when it comes to sounding more natural. Video after the break.
[Thanks to Stephen Walters for the tip!]
2026-02-06 11:00:44
[Prof MAD] runs us through The Hidden Power of Inductors — Why Coils Resist Change.
The less often used of the passive components, the humble and mysterious inductor is the subject of this video. The essence of inductance is a conductor’s tendency to resist changes in current. When the current is steady it is invisible, but when current changes an inductor pushes back. The good old waterwheel analogy is given to explain what an inductor’s effect is like.
There are three things to notice about the effect of an inductor: increases in current are delayed, decreases in current are delayed, and when there is no change in current there is no noticeable effect. The inductor doesn’t resist current flow, but it does resist changes in current flow. This resistive effect only occurs when current is changing, and it is known as “inductive reactance”.
After explaining an inductor’s behavior the video digs into how a typical inductor coil actually achieves this. The basic idea is that the inductor stores energy in a magnetic field, and it takes some time to charge up or discharge this field, accounting for the delay in current that is seen.
There’s a warning about high voltages which can be seen when power to an inductor is suddenly cut off. Typically a circuit will include snubber circuits or flyback diodes to help manage such effects which can otherwise damage components or lead to electric shock.
[Prof MAD] spends the rest of the video with some math that explains how voltage across an inductor is proportional to the rate of change of current over time (the first derivative of current against time). The inductance can then be defined as a constant of proportionality (L). This is the voltage that appears across a coil when current changes by 1 ampere per second, opposing the change. The unit is the volt-second-per-ampere (VsA-1) which is known as the Henry, named in honor of the American physicist Joseph Henry.
Inductance can sometimes be put to good use in circuits, but just as often it is unwanted parasitic induction whose effects need to be mitigated, for more info see: Inductance In PCB Layout: The Good, The Bad, And The Fugly.
2026-02-06 08:00:37
[GizmoThrill] shows off a design for an absolutely gorgeous, high-fidelity replica of the main character’s helmet from the video game Satisfactory. But the best part is the technique used to create the visor: just design around a cheap set of full-face “sunglasses” to completely avoid having to mold your own custom faceplate.
One of the most challenging parts of any custom helmet build is how to make a high-quality visor or faceplate. Most folks heat up a sheet of plastic and form it carefully around a mold, but [GizmoThrill] approached the problem from the other direction. After spotting a full-face sun visor online, they decided to design the helmet around the readily-accessible visor instead of the other way around.
The first thing to do with the visor is cover it with painter’s tape and 3D scan it. Once that’s done, the 3D model of the visor allows the rest of the helmet to be designed around it. In the case of the Satisfactory helmet, the design of the visor is a perfect match for the game’s helmet, but one could easily be designing their own custom headgear with this technique.
With the helmet 3D printed, [GizmoThrill] heads to the bandsaw to cut away any excess from the visor, and secure it in place. That’s all there is to it! Sure, you don’t have full control over the visor’s actual shape, but it sure beats the tons and tons of sanding involved otherwise.
There’s a video tour of the whole process that shows off a number of other design features we really like. For example, metal mesh in the cheek areas and in front of the mouth means a fan can circulate air easily, so the one doesn’t fog up the inside of the visor with one’s very first breath. The mesh itself is concealed with some greebles mounted on top. You can see all those details up close in the video, embedded just below.
The helmet design is thanks to [Punished Props] and we’ve seen their work before. This trick for turning affordable and somewhat gimmicky sunglasses into something truly time-saving is definitely worth keeping in mind.
