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.
The inspiration for this build started with a pair of 20″ steel framed fat tire bikes [Drew] picked up in a liquidation sale. He welded up a simple steel chassis, and attached the partial bicycle frame and forks to the chassis, using them as steerable front wheels. A short arm was welded to each of the fork, linking them together with threaded rods and rod ends that connect to centrally mounted handlebars. The rear driving wheels are from a 20″ e-bike conversion kit, with the disk brake assembly from the cannibalized bikes.
The solar part of this build comes in the form of three 175W flexible solar panels mounted on cedar frames, coming in at 10 lbs per mounted panel. [Drew] considered using conventional rigid solar panels, but they would have been 4-6 times heavier. The two panels mounted to the rear of the vehicle are on a hinged frame to allow easy access to the electronics below. Battery storage is made up of two 24V 100Ah batteries wired in series, connected to a 60A solar charge controller and the e-bike motor controllers.
The vehicle has a top speed of about 45km/h and 100km range on batteries alone. It might not be fast or engineered for maximum efficiency, but it looks like a ton of fun and relatively simple to build. As [Drew] says, it’s not a how-to for building a perfect solar-powered vehicle, it’s how he built one.
What do you do when you come across a cheap electric bicycle on Facebook Marketplace from a seller who has a few hundred of the same ones available? If you’re someone like [Max Helmetag], you figure that it’s probably legit since nobody would be reselling hundreds of Lime ridesharing e-bikes. Thus, it makes for an excellent project to see how usable an old ridesharing bicycle is. According to the information on the e-bike’s frame, it was manufactured in 2017, and based on the plastic still covering parts of the bike, it had barely been used, if at all.
[Tim] from the “Way Out West” Youtube channels has started a fun project — building a wooden pedal-car heavily inspired by “Bugsy Malone”. The kids-sized gangsters in that movie got around in kid-sized pedal cars. Apparently kid-sized [Tim] just loved the idea, but just didn’t have the skills or tools to try to build one. But the time has come, and he has spent years putting together a workshop, tools, and skills.
The goal is a 4-wheeled vehicle that can actually be enclosed, to keep the driver out of the rain. It would be petal powered, with an optional electric assist. It should be made of simple materials, like plywood and epoxy. The design would be freely shared, and the overall cost hopefully kept low. Come back after the link to find the rest of the story, including the monkey wrench thrown into the works. Continue reading “Pedal Car Vs Ministry Of Transport”→
When the bankruptcy of VanMoof, the company behind a series of e-bikes, was announced recently, many probably shrugged at this news. After all, what is an e-bike but a regular bicycle that has some electronics and a battery strapped to it to assist with cycling? Unfortunately for owners of a VanMoof e-bike, their fancy wheels come with a Bluetooth-connected smartphone app that somehow involves storing a special encryption key on the VanMoof servers, as detailed by [Gergely Orosz] at the Pragmatic Engineer. Without this key that is connected to your VanMoof account, your VanMoof app cannot communicate with your VanMoof e-bike.
Although basic functionality of the e-bike will be retained, features such as setting the gear modes, changing assistance mode, locking the bicycle and other features not exposed on the bicycle itself will be lost. Essentially this is the equivalent of losing the remote control to a modern-day TV and getting locked out of 90% of the device’s features.
Fortunately, as [Gergely] and others are (urgently) pointing out to VanMoof e-bike owners, this special key can be downloaded with a Key Exporter project on GitHub, as well as obtained and used with an alternative app by Cowboy Bikes, which is a competitor of VanMoof. The unfortunate reality remains, however, that should you lose this special key, you are going to be in a world of pain as your expensive e-bike now is mostly an e-brick.
If you’ve travelling via bike, you’ll know there’s a certain advantage to packing light. But what if you need to take your beefy desktop-replacement laptop with you on one of these trips? These power hungry machines can’t go far without their chargers (or a place to plug them in), which generally makes them poor traveling companions.
These drivetrains rely on electrical methods to transfer power in place of mechanical. The pedals are used to turn an electric generator, with power then sent to an electric motor which drives the rear wheel. The concept may sound overly complicated, but it does offer some benefits. The generator can change its operation to keep the rider pedalling at their most efficient, consistent rate. There would also be no chain to fall off, get snagged on clothing, or require regular maintenance.
It would make integrating regenerative braking possible, too, allowing the bike to harvest energy when going downhill too. This could be achieved with a storage battery or supercapacitor. As a bonus, it would be very easy to integrate power assist for the rider when tackling tough hills, for example. The lack of requirement for direct mechanical power transfer also means that there’s far more flexibility to design a bike with interesting geometry.
Such drive systems do give up some efficiency, however. All the power conversions between mechanical and electrical energy mean that a “digital drive” would likely only be 58% efficient. This compares poorly to the roughly 95% efficiency of power transfer in regular mechanically-driven bikes. There’s also a weight penalty, too.
Presnetly, there’s only one “digital drive” bike on the market – known as the Mando Footloose. It’s a swooping, folding, futuristic design, that has some feel issues when it comes to pedalling. And, given the added complexity and expense of these systems, it’s unlikely regular bikes or e-bikes are going away any time soon. Regardless, it’s fun to think about the potential for other drivetrain concepts to change the way we cycle. Video after the break.