Electric BMX With Friction Drive

November 26, 2020 by Bryan Cockfield 9 Comments

Electric bikes have increased in popularity dramatically over the past few years, and while you can easily buy one from a reputable bicycle manufacturer, most of us around here might be inclined to at least buy a kit and strap it to a bike we already have. There aren’t kits available for every bike geometry, though, so if you want an electric BMX bike you might want to try out something custom like [Shea Nyquist] did with his latest build. (Video, embedded below.)

BMX frames have a smaller front triangle than most bikes, so his build needed to be extremely compact. To that end, it uses two small-sized motors connected together with a belt, which together power a friction drive which clamps against the rear tire to spin it directly. This keeps the weight distribution of the bike more balanced as well when compared to a hub drive, where the motor is installed in the rear wheel. It also uses a more compact lithium polymer battery pack instead of the typical 18650 lithium ion packs most e-bikes use, and although it only has a range of around three miles it’s more than enough charge to propel it around a skate park.

The build boasts impressive numbers too, at 2.5 kW peak power per motor. This puts it in electric motorcycle territory, and it’s indeed fast despite its small stature. For a true high speed e-bike experience, though, you’ll need a slightly larger frame and motor even if it means tossing safety out of the window. Continue reading “Electric BMX With Friction Drive” →

RGB Party Bike Flashes With The Beat

November 22, 2020 by Lewin Day 9 Comments

One of the biggest dangers to a cyclist is not being seen at night. To counteract this, all manner of lighting and reflective gear is available to help ensure bicycles are seen on the streets. Of course, you don’t have to stop at the purely practical. [TechnoChic] decided to have some fun with her ride, festooning her party bike with many, many LEDs.

As you’d expect, the RGB illuminations are thanks to WS2812B LED strips. Running the show is a trio of Arduino Nano 33 IoTs – one for the LEDs on the bike’s frame, the other two mounted on the front and back wheels respectively. This allowed for the easy control of LEDs on the spokes without having to pass data and power lines to the rotating wheels. The LEDs on the frame are even music-reactive, with the Arduino sampling music input via one of its analog-to-digital converters.

Paired with a boombox on the bike, the build makes for a great way to hype up group rides through the city at night. We can imagine such a bike being an absolute hit at Critical Mass, though you’ve probably gotta add a laser or glitter cannon if you’re going to draw attention at Burning Man. If you’re tired of pedaling, you might consider an electric conversion, too. Video after the break.

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The Shipping Industry’s Transition To Atomic Power And Faster Deliveries

November 19, 2020 by Maya Posch 203 Comments

The transport of goods with cargo ships and especially container ships is the backbone of today’s economies, with about 90% of non-bulk cargo transported with them. This is in addition to the large number of oil tankers and LNG carriers. Unfortunately, due to their use of diesel engines they are also responsible for about 3.5% of the world’s CO2 emissions, in addition to 18 – 30% of nitrogen oxide and 9% of sulfur oxides.

Although the switch to low-sulfur diesel (ULSD) and the use of speed limits has reduced some of these pollutants, the shipping industry sees itself faced with the necessity to decarbonize in order to meet the obligations of the Paris Agreement. This essentially means finding a way to switch from diesel engines to an alternative which has comparable or better fuel costs, produces no or almost no pollutants and will not negatively affect logistics.

As a highly competitive, cut-throat industry, this does seem to leave shipping companies backed up against a wall. Yet an existing, proven technology just so happens to exist already which can be retrofitted into existing cargo ships. Continue reading “The Shipping Industry’s Transition To Atomic Power And Faster Deliveries” →

3D Printed Electric Motor Wants To Take Flight

November 18, 2020 by Al Williams 49 Comments

Airplanes and spacecraft have a big problem. The more engine or fuel you have, the more engine and fuel you need. That’s why aircraft use techniques to have lightweight structural members and do everything they can to minimize weight. A lighter craft can go further and carry more payload or supercargo. Electric motors are very attractive for aircraft, but they suffer from having less efficiency per kilogram than competing technologies. H3X thinks they can change that with their HPDM-250 integrated motor and inverter.

Although the 15 kg motor is still in testing, the claimed specifications are impressive: a peak power of 250 kW for 30 seconds and continuous torque of 95 Nm and 200 kW sustained. The company claims 96.7% efficiency. The claims are for the motor running at 20,000 RPM, so you’d need to add the weight of a gearbox for practical applications, but the company says this adds a mere 3 kg to the overall weight.

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Interactive Subway Map Talks You Through The Route

November 15, 2020 by Lewin Day 2 Comments

Old-school rail monitoring systems had amazing displays of stations and tracks covered in flashing lights that tracked the progress of trains along a route. While it’s unlikely you’ll fit such big iron from the mid-20th century in your home, you can get a similar aesthetic with [Kothe’s] interactive subway information display.

The display relies on an Arduino Mega 2560 Pro Mini as the brains of the operation. It drives strings of WS2812B LEDs which correspond to stations along the various metro lines in the area. Additionally, the microcontroller drives a 4.3″ Nextion LCD display. The Nextion displays have the benefit of acting as a self-contained human machine interface, running their own controller on board. This means the Arduino doesn’t have to spend cycles driving the display, and the Nextion hardware comes with a useful software package for quickly and easily designing GUI interfaces. For further feedback, a DFPlayer MP3 module is used to allow the system to playback prerecorded voice samples that provide information on the rail system. The attractive front panel is made with lasercut acrylic and a color printed acetate sheet.

It’s a build that bears striking similarity to real rail information systems fielded by railways around the world. We can imagine such a device being particularly useful in a backpacker’s hostel or university dorm to help those new to town find their way around. If you prefer a more stripped-back aesthetic, we’ve seen a barebones PCB build done as well. Video after the break.

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An EV Conversion Engineered As A Drop-in Replacement

November 15, 2020 by Jenny List 87 Comments

With electric vehicles such as the Tesla or the Leaf being all the rage and joined by fresh competitors seemingly every week, it seems the world is going crazy for the electric motor over their internal combustion engines. There’s another sector to electric traction that rarely hits the headlines though, that of converting existing IC cars to EVs by retrofitting a motor. The engineering involved can be considerable and differs for every car, so we’re interested to see an offering for the classic Mini from the British company Swindon Powertrain that may be the first of many affordable pre-engineered conversion kits for popular models.

Swindon Powertrain's demo Mini — Swindon Powertrain’s demo Mini

The kit takes their HPD crate EV motor that we covered earlier in the year, and mates it with a Mini front subframe. Brackets and CV joints engineered for the kit to drop straight into the Mini. The differential appears to be offset to the right rather than the central position of the original so we’re curious about the claim of using the Mini’s own driveshafts, but that’s hardly an issue that should tax anyone prepared to take on such a task. They can also supply all the rest of the parts for a turnkey conversion, making for what will probably be one of the most fun-to-drive EVs possible.

The classic Mini is now a sought-after machine long past its days of being dirt-cheap old-wreck motoring for the masses, so the price of the kit should be viewed in the light of a good example now costing more than some new cars. We expect this kit to have most appeal in the professional and semi-professional market rather than the budget end of home conversions, but it’s still noteworthy because it is a likely sign of what is to come. We look forward to pre-engineered subframes becoming a staple of EV conversions at all levels. The same has happened with other popular engine upgrades, and no doubt some conversions featuring them will make their way to the pages of Hackaday.

We like the idea of conversions forming part of the path to EV adoption, as we’ve remarked before.

Tech Hidden In Plain Sight: Gas Pumps

November 12, 2020 by Al Williams 67 Comments

Ask someone who isn’t technically inclined how a TV signal works or how a cell phone works, or even how a two-way switch in a hall light works and you are likely to get either a blank stare or a wildly improbable explanation. But there are some things so commonplace that even the most tech-savvy of us don’t bother thinking about. One of these things is the lowly gas pump.

Gas pumps are everywhere and it’s a safe bet to assume everyone reading this has used one at some point, most of use on a regular basis. But what’s really going on there?

Most of it is pretty easy to figure out. As the name implies, there must be a pump. There’s some way to tell how much is pumping and how much it costs and, today, some way to take the payment. But what about the automatic shut off? It isn’t done with some fancy electronics, that mechanism dates back decades. Plus, we’re talking about highly combustible materials, there has to be more to it then just a big tank of gas and a pump. Safety is paramount and, experientially, we don’t hear about gas stations blowing up two or three times a day, so there must be some pretty stout safety features. Let’s pay homage to those silent safety features and explore the tricks of the gasoline trade.

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