Scratch-built Electric Boat Shows Off Surprising Speed

June 7, 2025 by Bryan Cockfield 10 Comments

Electric cars are everywhere these days, but what about boats? Looking to go green on the water, [NASAT] put together this impressively nimble boat propelled by a pair of brushless motors.

The boat itself has a completely custom-built hull, using plywood as a mold for the ultimate fiberglass body. It’s a catamaran-like shape that seems to allow it to get on plane fairly easily, increasing its ultimate speed compared to a displacement hull. It gets up to that speed with two electric motors totaling 4 kW, mated to a belt-driven drivetrain spinning a fairly standard prop. Power is provided by a large battery, and the solar panel at the top can provide not only shade for the operator, but 300 W to charge the battery when the motors are not being used.

With the finishing touches put on, the small single-seat boat effortlessly powers around the water with many of the same benefits of an electric car: low noise, low pollution, a quiet ride, and a surprisingly quick feel. Electrification has come for other boats as well, like this sailing catamaran converted to electric-only. Even some commercial boats have begun to take the plunge.

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Hand Truck Turned Into Motorcycle

May 27, 2025 by Bryan Cockfield 13 Comments

For those motorcyclists looking to get a classic American-style cruiser, often the go-to brand is Harley-Davidson. However, these bikes not only have reputations for being stuck in the past, both in terms of design and culture, but they also tend to be extremely expensive—not only upfront, but in maintenance as well. If you want the style without all of that baggage, you might want to try out something like this custom motorcycle which not only looks the part, it reduces those costs by being built around a hand truck.

By the end of the project, though, the hand truck does not retain much of its original form or function. [Garage Avenger] has cut and welded it essentially into a custom frame for the diminutive motorcycle, while retaining much of its original look and feel. Keeping up with the costs savings aspect of this project, the four-stroke engine was free, although it did take some wrenching to get it running and integrated into the frame. A custom axle, a front end from another bike, a gas tank from an online retailer (that needed re-welding), and some wiring finishes out the build.

With a fresh paint job to match the original color of the hand truck, it’s off to the track. Of course it doesn’t have quite the performance of most street legal motorcycles, including some quirks with the handling and braking, but for the trails around [Garage Avenger]’s home it’s certainly a fun transportation mode he can add to his repertoire. If this is your first time seeing one of his projects, be sure to check out his other work including this drifting shopping cart and this turbine-powered sled.

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Jettison Sails For Electric Propulsion

May 21, 2025 by Bryan Cockfield 32 Comments

Although there are some ferries and commercial boats that use a multi-hull design, the most recognizable catamarans by far are those used for sailing. They have a number of advantages over monohull boats including higher stability, shallower draft, more deck space, and often less drag. Of course, these advantages aren’t exclusive to sailboats, and plenty of motorized recreational craft are starting to take advantage of this style as well. It’s also fairly straightforward to remove the sails and add powered locomotion as well, as this electric catamaran demonstrates.

Not only is this catamaran electric, but it’s solar powered as well. With the mast removed, the solar panels can be fitted to a canopy which provides 600 watts of power as well as shade to both passengers. The solar panels charge two 12V 100ah LifePo4 batteries and run a pair of motors. That’s another benefit of using a sailing cat as an electric boat platform: the rudders can be removed and a pair of motors installed without any additional drilling in the hulls, and the boat can be steered with differential thrust, although this boat also makes allowances for pointing the motors in different directions as well.

In addition to a highly polished electric drivetrain, the former sailboat adds some creature comforts as well, replacing the trampoline with a pair of seats and adding an electric hoist to raise and lower the canopy. As energy density goes up and costs come down for solar panels, more and more watercraft are taking advantage of this style of propulsion as well. In the past we’ve seen solar kayaks, solar houseboats, and custom-built catamarans (instead of conversions) as well.

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Automatic Transmission For Manual Transportation

May 15, 2025 by Bryan Cockfield 31 Comments

The drivetrain of most modern bicycles has remained relatively unchanged for nearly a century. There have been marginal upgrades here and there like electronic shifting but you’ll still mostly see a chain with a derailleur or two. [Matthew] is taking a swing at a major upgrade to this system by replacing the front derailleur with a torque converter, essentially adding an automatic transmission to his bicycle.

Most of us will come across a torque converter in passenger vehicles with automatic transmissions, but these use fluid coupling. [Matthew] has come up with a clever design that uses mechanical coupling instead using a ratchet and pawl mechanism. There are two gear ratios here, a 1:1 ratio like a normal bicycle crank and a 1.5:1 ratio that is automatically engaged if enough torque is applied to the pedals. This means that if a cyclist encounters a hill, the gear automatically shifts down to an easier gear and then will shift back once the strenuous section is finished.

[Matthew] machined all the parts for this build from scratch, and the heavy-duty solid metal parts are both impressive but also show why drivetrains like this haven’t caught on in the larger bicycling world since they’re so heavy. There have been some upgrades in internally geared hubs lately though, which do have a number advantages over traditional chain and derailleur-based bikes with the notable downside of high cost, and there have been some other interesting developments as well like this folding mechanical drivetrain and this all-electric one.

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You Wouldn’t Download A Helmet?

May 13, 2025 by Fenix Guthrie 34 Comments

Odds are, if you have ridden a bicycle for any amount of time, you have crashed. Crashes are fast, violent and chaotic events that leave you confused, and very glad to have a helmet. But what if there was another way of protecting your head? [Seth] decided to find out by taking a look at the Hövding airbag helmet.

The Hövding sits around your neck and looks somewhat akin to a neck pillow. It uses accelerometers situated in the fore and aft of the device to detect what it thinks is a crash. If a crash is detected, it will release a charge of compressed helium to inflate an airbag that wraps around the user’s head protecting a larger amount of the head then a traditional helmet. It also inflates around the wearer’s neck providing neck bracing in the impact further improving safety. The inflation process is incredibly fast and violent, very much akin to a car’s airbag. [Seth] demonstrated this on the process on two occasions to great effect, and to his amazement. While the idea of relying on computers to protect your head may sound ridiculous, studies have shown that the Hövding is safer than a regular helmet in certain situations.

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Trackside Observations Of A Rail Power Enthusiast

May 13, 2025 by Jenny List 60 Comments

The life of a Hackaday writer often involves hours spent at a computer searching for all the cool hacks you love, but its perks come in not being tied to an office, and in periodically traveling around our community’s spaces. This suits me perfectly, because as well as having an all-consuming interest in technology, I am a lifelong rail enthusiast. I am rarely without an Interrail pass, and for me Europe’s railways serve as both comfortable mobile office space and a relatively stress free way to cover distance compared to the hell of security theatre at the airport. Along the way I find myself looking at the infrastructure which passes my window, and I have become increasingly fascinated with the power systems behind electric railways. There are so many different voltage and distribution standards as you cross the continent, so just how are they all accommodated? This deserves a closer look.

So Many Different Ways To Power A Train

A British Rail Class 165 "Networker" train at a platform on Marylebone station, London. — Diesel trains like this one are for the dinosaurs.

In Europe where this is being written, the majority of main line railways run on electric power, as do many subsidiary routes. It’s not universal, for example my stomping ground in north Oxfordshire is still served by diesel trains, but in most cases if you take a long train journey it will be powered by electricity. This is a trend reflected in many other countries with large railway networks, except sadly for the United States, which has electrified only a small proportion of its huge network.

Of those many distribution standards there are two main groups when it comes to trackside, those with an overhead wire from which the train takes its power by a pantograph on its roof, or those with a third rail on which the train uses a sliding contact shoe. It’s more usual to see third rails in use on suburban and metro services, but if you take a trip to Southern England you’ll find third rail electric long distance express services. There are even four-rail systems such as the London Underground, where the fourth rail serves as an insulated return conductor to prevent electrolytic corrosion in the cast-iron tunnel linings. Continue reading “Trackside Observations Of A Rail Power Enthusiast” →

Restoring A Sinclair C5 For The Road

May 10, 2025 by Jenny List 26 Comments

The Sinclair C5 was Sir Clive’s famous first venture into electric mobility, a recumbent electric-assisted tricycle which would have been hardly unusual in 2025. In 1985, though, the C5 was so far out there that it became a notorious failure. The C5 retains a huge following among enthusiasts, though, and among those is [JSON Alexander, who has bought one and restored it.

We’re treated to a teardown and frank examination of the vehicle’s strengths and weaknesses, during which we see the Sinclair brand unusually on a set of tyres, and the original motor, which is surprisingly more efficient than expected. Sir Clive may be gone, but this C5 will live again.

We’ve had the chance to road test a C5 in the past, and it’s fair to say that we can understand why such a low-down riding position was not a success back in the day. It’s unusual to see one in as original a condition as this one, it’s more usual to see a C5 that’s had a few upgrades.