Tank Boots Are A Dangerous Way To Get Around Town

Rollerskates are all well and good, but they’re even more fun when they’re powered. Then again, why stick with wheels, when you can have the off-road benefits of tracked propulsion? That’s precisely what [Joel] was thinking when he built this impressive set of Tank Boots.

The build uses a set of tracks from a tracked snowblower, sourced for $50. The tracks are a simple design sans suspension, consisting of a pair of plastic wheels inside the tracks and run via a chain drive. Each snowblower track was given a metal frame with a ski boot and a motor, gearbox, and controller straight out of a power drill. Power was courtesy of a lithium-polymer battery pack.

Riding the boots isn’t easy, with falls and tumbles rather common. Regardless, they get around great offroad in a way that regular rollerblades never could. Bolted together, they make a great tank chair, too. We’ve actually looked at the benefits of tracks versus wheels before, too. Video after the break.

Can A $3200 Kit Convert Your Car To Electric Power?

Whether hardcore petrolheads like it or not, we appear to be living through the final years of the internal combustion engine. In many countries there are legislative timetables in place for their eventual phasing out, and even those which remain in production are subject to ever more stringent emissions legislation. If there’s a problem with the EVs with which we’re expected to replace our fossil fuel vehicles it’s the cost, those things are still very expensive. An Aussie student has an interesting idea that’s won the James Dyson Prize: a low cost conversion for existing vehicles that bolts onto their rear wheel hubs.

Electric conversion of fossil fuel cars is nothing new, indeed we’ve brought you news of units designed to replace the original engine and transmission. Neither are wheel hub motors new, but the difference with this system is that it doesn’t require significant mechanical modification to the vehicle. It retains the old engine, and this motor sits inside each rear wheel.

It almost seems too good to be true, but a closer reading shows the rotor bolted on one side to the old wheel hub and on the other side to the wheel. The stator meanwhile is bolted to the existing brake caliper mountings. This would lead to a slightly wider track and a greater unsprung weight, but we can see that it would work. Besides the motor there’s a battery pack for the spare wheel well and a set of electrically-powered systems to supply the brake servo vacuum and other services. The idea is that this whole kit could be fitted for 5000 Australian dollars, which is somewhere south of $3200 USD. It’s not perfect and it still involves hauling around the dead weight of an unused engine, but we can see it might still have a niche. If, and that’s a big if, it ever makes it to market, that is.

Meshtastic And Owntracks To Kick Your Google Habit

I have an admission to make. I have a Google addiction. Not the normal addiction — I have a problem with Google Maps, and the timeline feature. I know, I’m giving my location data to Google, who does who-knows-what-all with it. But it’s convenient to have an easy way to share location with my wife, and very useful to track my business related travel for each month. What we could really use is a self-hosted, open source system to track locations and display location history. And for bonus points, let’s include some extra features, like the ability to track vehicles, kids, and pets that aren’t carrying a dedicated Internet connection.

You can read the title — you know where we’re going with this. We’re setting up an Owntracks service, and then tying it to Meshtastic for off-Internet usability. The backbone that makes this work is MQTT, a network message bus that has really found its niche in the Home Assistant project among others. It’s a simple protocol, where clients send brief messages labeled by topic, and can also subscribe to specific topics. For this little endeavor we’ll use the Mosquito MQTT broker.

One of the nice things about MQTT is that the messages are all text strings, and often take the form of JSON. When trying to get two applications to talking using a shared MQTT server, there may need to be a bit of translation. One application may label a field latitude, and the other shortens it to lat. The glue code to put these together is often known as an MQTT translator, or sometimes an MQTT bridge. This is a program that listens to a given topic, ingests each message, and sends it back to the MQTT server in a different format and topic name.

The last piece is Owntracks, which has a recorder project, which pulls locations from the MQTT server, and stores it locally. Then there’s Owntracks Frontend, which is a much nicer user interface, with some nice features like viewing movement a day at a time. Continue reading “Meshtastic And Owntracks To Kick Your Google Habit”

E-Bikes Turned Solar Car

There is something to be said for a vehicle that gains range just by standing outside in the sun. In the video after the break, [Drew Builds Stuff] demonstrates how he turned a pair of bicycles into a solar-powered vehicle.

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.

Continue reading “E-Bikes Turned Solar Car”

Reviving An Old Lime-E Beta Rideshare E-Bicycle

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.

Continue reading “Reviving An Old Lime-E Beta Rideshare E-Bicycle”

Exploring Ground-Effect With A Quadcopter

The ground-effect (GE) refers to the almost mystical property where the interaction of the airflow around an aircraft’s wing and the ground massively increases efficiency due to the reduction of lift-dependent drag, perhaps best demonstrated by the Soviet Lun-class “ekranoplans” of the 1980s and 90s. Interestingly, this principle also applies to rotary aircraft, which led the [rctestflight] YouTube channel to wonder what would happen if a quadcopter were to be adapted for GE.

As noted on the Wikipedia entry for Ground-effect vehicle (GEV), it’s essential to have some kind of forward motion. With a rotorcraft like a helicopter or quadcopter this motion is already provided by the spinning propeller, which makes it noticeably easier to get the aircraft into the ground-effect. operating mode. Following the notion that the GE becomes noticeable at an altitude that’s dependent on the length of the aircraft’s wings, this got translated into putting the largest propellers available on the custom inverted-prop (to put them lower to the ground) quadcopter, to see what effect this would have on the quadcopter’s performance. As demonstrated by the recorded current drawn (each time with a fully charged battery), bigger is indeed better, and the GE effect is indeed very noticeable for a quadcopter.

Getting a usable GEV out of the basic inverted-prop quadcopter required some more lateral thinking, however, as it was not very easy to control this low to the ground. Here following design cues from skirtless hovercraft designs helped a lot, essentially drawing on the Coandă effect. Although this improved performance, at this point the quadcopter had been fitted with a fifth propeller for propulsion and was skidding about more like a skirtless hovercraft and less of a quadcopter.

Although great for scaring the living daylights out of unsuspecting water-based wildlife, what this unfortunately demonstrates is that GEVs are still hard, no matter which form they take. At the very least it does make for an excellent introduction into various aspects of aerodynamics.

Continue reading “Exploring Ground-Effect With A Quadcopter”

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.