Robotic Platform Turns Shop Vac Into Roomba

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

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

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

[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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300 Amps Through An Open Source Speed Controller

Sometimes, a little puny matchbox-sized electronic speed controller (ESC) won’t do the job. If you find yourself looking for something heftier, say, in the range of hundreds of amps, you might look towards a design like the MP2 ESC. [owhite] has built an example of the design that can deliver some serious power.

[owhite’s] build has some serious specs: it’s rated to offer up to 300 amps at up to 150 volts, though thus far, it’s only been tested at up to 100 V. Like the original MP2, which hails from the Endless Sphere forums, it’s designed to be compatible with VESC code using the STM32F405 microcontroller. It’s intended for driving high-powered traction motors in applications like e-bikes and electric scooters, as you might have guessed by its potential output power being well into the tens of kilowatts range.

If you’re eager to build your own, you can do so, with the design files on GitHub. Just note that you’ll need some hefty parts to handle the juice, including beefy MOSFETS and juicy capacitors rated at 160 V.

Open source motor controllers abound of late, and we’ve featured a few in recent times. Just remember that astute design and using parts within their means is the key to avoiding letting the smoke out! Continue reading “300 Amps Through An Open Source Speed Controller”

An Open-Source Ebike Motor Controller

DIY e-bikes are often easy to spot. If they’re not built out of something insane like an old washing machine motor, the more subtle kits that are generally used still stand out when compared to a non-assisted bike. The motors tend to be hub- or mid-drive systems with visible wires leading to a bulky battery, all of which stand out when you know what to look for. To get a stealthy ebike that looks basically the same as a standard bicycle is only possible with proprietary name-brand solutions that don’t lend themselves to owner repair or modification, but this one has at least been adapted for use with an open source motor controller.

The bike in use here is a model called the Curt from Estonian ebike builder Ampler, which is notable in that it looks indistinguishable from a regular bicycle with the exception of the small 36-volt, 350-watt hub motor somewhat hidden in the rear wheel. [BB8] decided based on no reason in particular to replace the proprietary motor controller with one based on VESC, an open-source electric motor controller for all kinds of motors even beyond ebikes. Installed on a tiny Arduino, it fits inside the bike’s downtube to keep the stealthy look and can get the bike comfortably up to around 35 kph. It’s also been programmed to turn on the bike’s lights if the pedals are spun backwards, and this method is also used to change the pedal assist level, meaning less buttons and other user-interface devices on the handlebars. Continue reading “An Open-Source Ebike Motor Controller”

A silver front loader cargo bike sits in a parking lot in front of an electric vehicle charger. A cable runs from the charger to the bike.

Fast Charging A Cargo Bike From An Electric Car Charger

Fast charging is all the rage with new electric cars touting faster and faster times to full, but other EVs like ebikes and scooters are often left out of the fun with exceedingly slow charging times. [eprotiva] wanted to change this, so he rigged up a fast charging solution for his cargo bike.

Level 2 electric vehicle chargers typically output power at 7 kW with the idea you will fill up your electric car overnight, but when converted down to 60 V DC for a DJI Agras T10 battery, [eprotiva] is able to charge from 20% to 100% capacity in as little as 7 minutes. He originally picked this setup for maxing the regen capability of the bike, but with the high current capability, he found it had the added bonus of fast charging.

The setup uses a Tesla (NACS) plug since they are the most plentiful destination charger, but an adapter allows him to also connect to a J1772 Type 1 connector. The EV charging cable is converted to a standard 240 V computer cable which feeds power to a drone charger. This charger can be set to “fast charge” and then feeds into the battery unit. As an added bonus, many chargers that do cost money don’t start charging until after the first five minutes, so the bike is even cheaper to power than you’d expect.

For some reason, you can watch him do this on TikTok too.

If you too want to join the Personal EV Revolution, be sure to checkout how to choose the right battery for your vehicle and a short history of the Segway.