ebike

46 Articles

Hydroelectric Generator Gets Power From Siphoning

January 21, 2025 by 38 Comments

Siphons are one of those physics phenomena that, like gyroscopes, non-Newtonian fluids, and electricity, seem almost magical. Thanks to atmospheric pressure, simply filling a tube with liquid and placing the end of the tube below the liquid level of a container allows it to flow against gravity, over a barrier, and down into another container without any extra energy inputs once the siphon is started. They’re not just tricks, though; siphons have practical applications as well, such as in siphon-powered hydroelectric turbine.

This is an iteration of [Beyond the Print]’s efforts to draw useful energy from a local dam with an uneconomic amount of water pressure and/or volume for a typical hydroelectric power station. One of his earlier attempts involved a water wheel but this siphon-based device uses a more efficient impeller design instead, and it also keeps the generator dry as well. Using 3″ PVC piping to channel the siphon, as well as a short length of thinner pipe to attach a shop vac for priming the siphon, water is drawn from the reservoir, up the pipe, and then down through the impeller which spins a small DC generator.

This design is generating about 9 V open-circuit, and we’d assume there’s enough power available to charge a phone or power a small microcontroller device. However, there’s a ton of room for improvement here. The major problem [Beyond the Print] is currently experiencing is getting air into the system and having the siphon broken, which he’s solved temporarily by adding a bucket at the outflow. This slows down the water though, so perhaps with any air leaks mitigated the power generation capabilities will be greatly increased.

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E-Bike Motor Gets New Life As Hydro Plant

January 5, 2025 by 54 Comments

For economic reasons, not every lake with a dam can support a hydroelectric power plant. Some rivers or creeks are dammed for flood control or simply for recreation, and don’t have the flow rate or aren’t deep enough to make the investment of a grid-scale generation facility worthwhile. But for those of us with a few spare parts around and access to a small lake, sometimes it’s possible to generate a usable amount of energy with just a bit of effort.

[Beyond the Tint] is building this mostly as a proof-of-concept, starting with a 1,000W hub motor from an e-bike that’s been removed from its wheel. A 3D-printed waterwheel attachment is installed in its place, and the fixed shaft is attached to a homemade ladder-looking mechanism that allows the entire generator to be lowered into the flow of a moving body of water, in this case, a small stream. A bridge rectifier converts the AC from the hub motor (now a generator) into DC, and after a few measurements and trials, [Beyond the Tint] produced over 30W with the first prototype.

A second prototype was made with feedback from the first video he produced, this time with an enclosed paddlewheel. This didn’t appear to make much difference at first, but a more refined impeller may make a difference in future prototypes. Small-scale hydropower is a fairly popular challenge to tackle, especially in the off-grid community. With access to even a small flowing stream and enough elevation change, it’s possible to build something like this generator out of parts from an old washing machine.

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Disposable Vape Batteries Power EBike

November 7, 2024 by 15 Comments

There are a lot of things that get landfilled that have some marginal value, but generally if there’s not a huge amount of money to be made recycling things they won’t get recycled. It might not be surprising to most that this is true of almost all plastic, a substantial portion of glass, and even a lot of paper and metals, but what might come as a shock is that plenty of rechargeable lithium batteries are included in this list as well. It’s cheaper to build lithium batteries into one-time-use items like disposable vape pens and just throw them out after one (or less than one) charge cycle, but if you have some spare time these batteries are plenty useful.

[Chris Doel] found over a hundred disposable vape pens after a local music festival and collected them all to build into a battery powerful enough for an ebike. Granted, this involves a lot of work disassembling each vape which is full of some fairly toxic compounds and which also generally tend to have some sensitive electronics, but once each pen was disassembled the real work of building a battery gets going. He starts with testing each cell and charging them to the same voltage, grouping cells with similar internal resistances. From there he assembles them into a 48V pack with a battery management system and custom 3D printed cell holders to accommodate the wide range of cell sizes. A 3D printed enclosure with charge/discharge ports, a power switch, and a status display round out the build.

With the battery bank completed he straps it to his existing ebike and hits the trails, easily traveling 20 miles with barely any pedal input. These cells are only rated for 300 charge-discharge cycles which is on par for plenty of similar 18650 cells, making this an impressive build for essentially free materials minus the costs of filament, a few parts, and the sweat equity that went into sourcing the cells. If you want to take an ebike to the next level of low-cost, we’d recommend pairing this battery with the drivetrain from the Spin Cycle.

Thanks to [Anton] for the tip!

Robotic Platform Turns Shop Vac Into Roomba

May 8, 2024 by 14 Comments

The robotic revolution is currently happening, although for the time being it seems as though most of the robots are still being generally helpful to humanity, whether that help is on an assembly line, help growing food, or help transporting us from place to place. They’ve even showed up in our homes, although it’s not quite the Jetsons-like future yet as they mostly help do cleaning tasks. There are companies that will sell things like robotic vacuum cleaners but [Clay Builds] wanted one of his own so he converted a shop vac instead.

The shop vac sits in a laser-cut plywood frame and rolls on an axle powered by windshield wiper motors. Power is provided from a questionable e-bike battery which drives the motors and control electronics. A beefy inverter is also added to power the four horsepower vacuum cleaner motor. The robot has the ability to sense collisions with walls and other obstacles, and changes its path in a semi-random way in order to provide the most amount of cleaning coverage for whatever floor it happens to be rolling on.

There are a few things keeping this build from replacing anyone’s Roomba, though. Due to the less-than-reputable battery, [Clay Builds] doesn’t want to leave the robot unattended and this turned out to be a good practice when he found another part of the build, a set of power resistors meant to limit current going to the vacuum, starting to smoke and melt some of the project enclosure. We can always think of more dangerous tools to attach a robotic platform to, though.

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Ultimate Power: Lithium-Ion Batteries In Series

April 4, 2024 by 52 Comments

At some point, the 3.6 V of a single lithium ion battery just won’t do, and you’ll absolutely want to stack LiIon cells in series. When you need high power, you’ve either got to increase voltage or current, and currents above say 10 A require significantly beefed up components. This is how you’re able to charge your laptop from your USB-C powerbank, for instance.

Or maybe you just need higher voltages, and don’t feel like using a step-up converter, which brings along with it some level of inefficiency. Whatever your reasons, it’s time to put some cells into series. Continue reading “Ultimate Power: Lithium-Ion Batteries In Series” →

Paddling Help From Electric-Assisted Kayak

December 31, 2023 by 15 Comments

Electric-assisted bicycles, or ebikes, are fundamentally changing the way people get around cities and towns. What were once sweaty, hilly, or difficult rides have quickly turned into a low-impact and inexpensive ways around town without foregoing all of the benefits of exercise. [Braden] hoped to expand this idea to the open waters and is building what he calls the ebike of kayaking, using the principles of electric-assisted bicycles to build a kayak that helps you get where you’re paddling without removing you completely from the experience.

The core of the project is a brushless DC motor originally intended a hydrofoil which is capable of providing 11 pounds (about 5 kg) of thrust. [Braden] has integrated it into a 3D-printed fin which attaches to the bottom of his inflatable kayak. The design of the fin took a few iterations to get right, but with a working motor and fin combination he set about tuning the system’s PID controller in a tub before taking it out to the open water. With just himself, the battery, and the motor controller in the kayak he’s getting about 14 miles of range with plenty of charge left in the battery after the trips.

[Braden]’s plans for developing this project further will eventually include a machine learning algorithm to detect when the rider is paddling and assist them, rather than simply being a throttle-operated motor as it exists currently. On a bicycle, strapping a sensor to the pedals is pretty straightforward, but we expect detecting paddling to be a bit more of a challenge. There are even more details about this build on his personal project blog. We’re looking forward to seeing the next version of the project but if you really need to see more boat hacks in the meantime be sure to check out [saveitforparts]’s boat which foregoes sails in favor of solar panels.

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Hubless E-Bike Is Nostalgic

December 16, 2023 by 12 Comments

[Chris Makes Stuff] is an aptly named channel. His recent video shows how he took a kid’s electric motorcycle toy and built a “penny farthing” bicycle. You might not know the bike by that name, but when you see it in the video below, you’ll recognize it. These Victorian-era bikes used a single large wheel before chain drives on a bike became a thing.

Of course, the big part of this — literally and figuratively — is the giant front wheel. There’s a second video showing how it was built in layers using wood.

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