The Hovercraft Revolution And Finding The Right Niche For A Technology

December 11, 2024 by Maya Posch 41 Comments

In the world of transportation, some technologies may seem to make everything else appear obsolete, whether it concerns airplanes, magnetic levitation or propelling vehicles and craft over a cushion of air. This too seemed to be the case with hovercraft when they exploded onto the scene in the 1950s and 1960s, seemingly providing the ideal solution for both commercial and military applications. Freed from the hindrances of needing a solid surface to travel upon, or a deep enough body of water to rest in, hovercraft gave all the impressions of combining the advantages of aircraft, ships and wheeled vehicles.

Yet even though for decades massive passenger and car-carrying hovercraft roared across busy waterways like the Channel between England & mainland Europe, they would quietly vanish again, along with their main competition in the form of super fast passenger catamarans. Along the English Channel the construction of the Channel Tunnel was a major factor here, along with economical considerations that meant a return to conventional ferries. Yet even though one might think that the age of hovercraft has ended before it ever truly began, the truth may be that hovercraft merely had to find its right niches after a boisterous youth.

An example of this can be found in a recent BBC article, which covers the British Griffon Hoverwork company, which notes more interest in new hovercraft than ever, as well as the continued military interest, and from rescue workers.

Continue reading “The Hovercraft Revolution And Finding The Right Niche For A Technology” →

Electric Bike Uses No Electronics, Weird Motor

December 9, 2024 by Lewin Day 24 Comments

E-bikes combine a bicycle with a big lithium battery, a speed controller, and a motor. What you get from that combination is simple, efficient transportation. [Tom Stanton] wanted to build an e-bike himself, but he did it without any of the fancy electronic components. But the real gem? The weird janky motor he built to run it.

The concept is simple. An e-bike is electric, in that it has an electric motor and a source of electric power. However, [Tom] intended to eliminate the electronic parts—the speed controller, any battery balancing hardware, and the like. Just think no transistors and microchips and you’ve got the right idea. Basically, [Tom] just built an e-bike with motor weak enough that it doesn’t need any fancy throttle control. He can just turn the motor hard on or off with a switch.

The bike is built around a reed switch motor. This uses magnets on a rotor, which interact with a reed switch to time pulses of electricity to coils which drive the motor. [Tom] wound the coils and built the motor from scratch using 3D printed components. The project quickly ran into problems as the reed switch began to suffer degradation from arcing, which [Tom] solved with some innovative tungsten contacts.

Controlling the bike is pretty simple—there’s just a switch connecting a capacitor bank to the motor to provide power on command. No electronics! However, [Tom] has also neatly set up the motor to charge a bank of supercapacitors when coasting downhill. In this regard, the bike can store power on a descent and then use it for a boost when required later on. Between the weird motor and the weedy capacitor bank, it doesn’t do much, but it does work.

If he’s looking for a more potent power source, perhaps the answer is already out on the street — in the form of a battery pack salvaged from the cells in discarded vapes.
Continue reading “Electric Bike Uses No Electronics, Weird Motor” →

Front view of blue bicycle with Raspberry Pi webserver

Pedaling Your Mobile Web Server Across The Globe

December 8, 2024 by Heidi Ulrich 11 Comments

We tinkerers often have ideas we know are crazy, and we make them up in the most bizarre places, too. For example, just imagine hosting a website while pedaling across the world—who would (not) want that? Meet [Jelle Reith], a tinkerer on an epic cycling adventure, whose bicycle doubles as a mobile web server. [Jelle]’s project, jelle.bike, will from the 6th of December on showcase what he’s seeing in real time, powered by ingenuity and his hub dynamo. If you read this far, you’ll probably guess: this hack is done by a Dutchman. You couldn’t be more right.

At the heart of [Jelle]’s setup is a Raspberry Pi 4 in a watertight enclosure. The tiny powerhouse runs off energy generated by a Forumslader V3, a clever AC-to-DC converter optimized for bike dynamos. The Pi gets internet access via [Jelle]’s phone hotspot, but hosting a site over cellular networks isn’t as simple as it sounds. With no static IP available, [Jelle] routes web traffic through a VPS using an SSH tunnel. This crafty solution—expanded upon by Jeff Geerling—ensures seamless access to the site, even overcoming IPv6 quirks.

The system’s efficiency and modularity exemplify maker spirit: harnessing everyday tools to achieve the extraordinary. For more details, including a parts list and schematics, check out [Jelle]’s Hackaday.io project page.

Gas Gauge Upgrade Keeps VW Restoration Classy

December 4, 2024 by Dan Maloney 49 Comments

Getting every detail perfectly right is often the goal in automotive restorations, and some people will go to amazing lengths to make sure the car looks and acts just like it did when it rolled off the dealer’s lot all those decades ago. That ethos can be pushed a little too far, though, especially with practical matters like knowing how much gas is left in the tank. Get that wrong and you’ll be walking.

Unwilling to risk that cruel fate with his restoration of 1978 Volkswagen Bus, [Pegork] came up with a replacement fuel gauge that looks identical to the original meter, but actually works. The gas gauges on ’60s and ’70s VWs were notoriously finicky, and when they bothered to work at all they were often wildly inaccurate. The problem was usually not with the sender unit in the tank, but the gauge in the dash, which used a bimetallic strip heated by a small coil of wire to deflect a needle. [Pegor]’s “SmoothBus” modification replaces the mechanical movement with a micro servo to move the needle. The variable voltage coming back from the fuel sender is scaled through a voltage divider and read by an analog input on an ATtiny85, which does a little algorithmic smoothing to make sure the needle doesn’t jump around too much. A really nice addition is an LED low fuel indicator, a feature that would have saved us many walks to the gas station back in our VW days. Except for the extra light, the restored gauge looks completely stock, and it works far better than the original.

Hats off to [Pregor] for this fantastic restomod. As we’ve noted before, classic VWs are perhaps the most hackable of cars, and we applaud any effort to keep these quirky cars going.

Tailwheel Trainer Go-Cart To Avoid Wrecked Planes

December 1, 2024 by Danie Conradie 16 Comments

Taildraggers remain a popular configuration for small aircraft, but they come with a significant risk during ground handling: ground loops. If the tail gets too far off course, it can swing around completely, often damaging or destroying aircraft if a wing hits the ground. Avoiding ground loops requires good rudder and brake control, and there currently isn’t a good way to learn it without getting into an actual aircraft. [Trent Palmer] is a pilot and who has been thinking about this problem for a few years, so he built a 3-wheeled electric go-cart to help pilots train their ground handling.

The cart is controlled exactly like a taildragger, with a pair of rudder pedals connected to the single steerable via cables, and springs to add some response delay. Independent hydraulic brakes on each main wheel, operated by toe pedals, further simulate the control on many aircraft. The main wheel are controlled with a throttle lever, with a differential to allow them to rotate at different speeds. The cart is unforgiving, and requires constant corrections with the pedals to keep it going straight.[Trent] had few pilot and non-pilot friends try out the cart, and even the experienced tailwheel pilots got into ground loop. It might be bit too sensitive, but everyone agreed that mastering this cart would significantly improve ground handling skills in actual aircraft.

Repairing a damaged aircraft can cost several thousand dollar, so a cheap training tool like this could prove invaluable flight schools and even individual pilots. [Trent] doesn’t have big plans for commercialization, but we wouldn’t be surprised if it goes that way.

Taildraggers are especially popular as bush planes, with many tracing their heritage from the humble Piper J-3 Cub. We’ve seen some extreme extreme modern bush planes, like [Mike Patey]’s Scrappy and Draco builds. Continue reading “Tailwheel Trainer Go-Cart To Avoid Wrecked Planes” →

Electric Motors Run Continuously At Near-Peak Power

November 26, 2024 by Bryan Cockfield 35 Comments

For a lot of electrical and mechanical machines, there are nominal and peak ratings for energy output or input. If you’re in marketing or advertising, you’ll typically look at the peak rating and move on with your day. But engineers need to know that most things can only operate long term at a fraction of this peak rating, whether it’s a power supply in a computer, a controller on an ebike, or the converter on a wind turbine. But this electric motor system has a unique cooling setup allowing it to function at nearly full peak rating for an unlimited amount of time.

The motor, called the Super Continuous Torque motor built by German automotive manufacturer Mahle is capable of 92% of its peak output power thanks to a unique oil cooling system which is able to remove heat and a rapid rate. Heat is the major limiter for machines like this; typically when operating at a peak rating a motor would need to reduce power output to cool down so that major components don’t start melting or otherwise failing. Given that the largest of these motors have output power ratings of around 700 horsepower, that’s quite an impressive benchmark.

The motor is meant for use in passenger vehicles but also tractor-trailer style trucks, where a motor able to operate at its peak rating would mean a smaller size motor or less weight or both, making them easier to fit into the space available as well as being more economically viable. Mahle is reporting that these motors are ready for production so we should be seeing them help ease the transportation industry into electrification. If you’re more concerned about range than output power, though, there’s a solution there as well so you don’t have to be stuck behind the times with fossil fuels forever.

Thanks to [john] for the tip!

3D Printed Boat Uses Tank Tracks For Amphibious Propulsion

November 23, 2024 by Lewin Day 16 Comments

Boats normally get around with propellers or water jets for propulsion. Occasionally, they use paddles. [Engineering After Hours] claims he is “changing the boat game forever” with his new 3D printed boat design that uses a tank tread for propulsion instead. Forgive him for the hyperbole of the YouTuber. It’s basically a modified paddle design, but it’s also pretty cool.

It works on land, even if it doesn’t steer well!

The basic idea is simple enough—think “floating snowmobile” and you’re in the ballpark. In the water, the chunky tank track provides forward propulsion with its paddle-like treads. It’s not that much different from a paddle wheel steamer. However, where it diverges is that it’s more flexible than a traditional paddle wheel.

The tracked design is actually pretty good at propelling the boat in shallow water without getting stuck. In fact, it works pretty well on dirt, too! The video covers the basic concept, but it also goes into some detail regarding optimizing the design, too. Getting the float and track geometry right is key to performance, after all.

If you’re looking to build an oddball amphibious craft, maybe working with the snowmobile concept is worth your engineering time. Continue reading “3D Printed Boat Uses Tank Tracks For Amphibious Propulsion” →