Hoverboard Becomes Kart In Easy Build

May 6, 2020 by Zoe Skyforest 11 Comments

The hoverboard furnished to the world in the 2010s was not the one promised to us by Hollywood. Rather than a skateboard without wheels, we got a handsfree Segway, delivering faceplanting fun for the whole family. [Emanuel Feru] decided to repurpose his into a much safer electric kart.

The build starts with a pedal-powered children’s kart, which has its drivetrain and rear axle removed. The hoverboard is bolted in its place, with its track and wheel size conveniently similar enough to make this practical. The original circuitboards are left in place, reprogrammed with custom firmware for their new role. [Emanuel]’s code enables the stock hardware to drive the motors with Field Oriented Control, for better efficiency. Additionally, the hardware reads a set of pedals cribbed from a PC racing wheel for throttle input, replacing the original gyrometer setup. With field weakening enabled, [Emanuel] reports the kart reaching up to 40 km/h.

It’s a tidy hack that makes great use of all the original hoverboard hardware, rather than simply throwing new parts at the problem. We’ve seen similar hacks before, with Segways in lieu of 2015’s most dangerous Christmas gift. Video after the break.

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How To Get Into Cars: Forced Induction

April 16, 2020 by Zoe Skyforest 43 Comments

For those addicted to automotive thrills, there’s always an underlying lust for more power. For those chasing a bigger number, forced induction is one of the most effective ways to achieve it. In addition to more grunt, you get a whole bunch of fun new noises, too. For those with a naturally aspirated car, here’s how you go about converting to forced induction.

Superchargers and Turbos

When we talk about forced induction, we’re talking about forcing more air into the engine under pressure. With more air available, it’s possible to fully combust more fuel, creating more power. The two most common ways of doing this are supercharging and turbocharging. We’ll be using the common automotive vernacular here, so those eager to bicker about terminology from the early 20th century aircraft industry best do it in the comments. Continue reading “How To Get Into Cars: Forced Induction” →

COVID-19 And The State Of The Climate

April 10, 2020 by Zoe Skyforest 48 Comments

The novel coronavirus sweeping the globe has led governments to institute widespread quarantines to stem the spread. Many industries have slowed production or shutdown entirely, and economic activity has slowed to a crawl. This has naturally led to a sudden reduction in greenhouse gas emissions. But how great will the effect be, and will it buy us any real time?

On The Ground

Nitrogen dioxide levels in China have dropped sharply with the reduction in industrial activity due to COVID-19. Image source: NASA

In the wake of COVID-19, good news stories have sprung up as people look for a silver lining. Unfortunately, these stories aren’t always true. There aren’t dolphins in the waters of Venice, though the water has cleared due to reduced boat activity. And drunken elephants did not begin roaming the mountains of China.

Despite this, there have been notable reductions in emissions in several areas due to government-mandated lockdowns. Northern Italy is seeing a much lower concentration of nitrogen dioxide, likely due to reduced industrial and vehicular activity. Carbon monoxide levels have similarly dropped in New York, while China has seen its carbon emissions temporarily drop by a full 25%.

On the surface of it, these are all promising numbers. Many are cautiously optimistic that this could be a major development to help stave off the worst of climate change for a little longer. Nonetheless, it’s early days yet, and what happens after the crisis passes is just as important as what’s happening now.

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PCB Mill Turns Out Stylish Necklace

April 7, 2020 by Zoe Skyforest 6 Comments

When needing a custom PCB, most of us will whip up design files and send them off to a board house. Prices are low and turnaround times are bearable, with quality that’s difficult to replicate at home. The old methods still have some value however, as [Bantam Tools] demonstrate with this attractive glowing hummingbird necklace.

The back side of the pendant neatly hides a button cell battery and a small SMD switch.

The necklace is made of copper-clad board, the type typically used by those who would etch their own PCBs at home. In this case, the board is placed on a [Bantam Tools] mill, which removes copper strategically and cuts out the final shape. This creates a series of traces on the back for a battery, LEDs and a small swtich, while creating areas on the other side of the board for light to shine through.

With a battery installed, the LEDs on the back side of the necklace glow through the fiberglass for a beautiful effect. With a PCB mill and a reflow oven, it’s remarkably easy to make, too. Of course, if you like your parts density a little higher, these FPGA earrings might be more your speed!

Self-Glowing Ring Is Its Own Battery

April 4, 2020 by Zoe Skyforest 19 Comments

LED jewelry has always been a popular part of the maker community. Oftentimes, coin cells are used as a compact source of power, or wires are run to discreet hidden battery packs. [OguzC3] went another route, however, creating a glowing ring which works as its own battery.

The design will be familiar to those who have done high-school experiments on basic batteries. An aluminium pipe forms the inner surface of the ring, which is then wrapped in a layer of newspaper. A copper outer ring is then placed outside. When soaked in a salt water solution, this forms a basic battery. The voltage output is only around 0.5 volts, so a joule thief circuit is built into the ring to step this up high enough to drive an LED. [OguzC3] reports that the ring lasts several hours at a time, and only needs a quick rinse in fresh salty water to recharge.

It’s a creative concept, and the final piece looks like a magical object from the world of fantasy. It would make a great addition to any cosplay, and we’re sure the technique could be adapted to other accoutrements, too. A similar experiment done in a more extreme way is this electric car charged via lemons. If you’ve got your own battery chemistry project cooking up at home, be sure to let us know!

A Touchless Handwashing Timer Comes In Handy

April 3, 2020 by Zoe Skyforest 23 Comments

In 2020, it’s no longer enough to simply wash your hands. You’ve got to do it right. Proper process involves rubbing soap and water over every surface of your hands, and taking a full 20 seconds to do the job. While many recommend singing various popular songs to keep time, that can be more than a little embarassing in shared spaces. [Alex Glow] instead created this simple timer to help out.

The timer is built on the Adafruit Circuit Playground Express, a devboard that features 10 RGB LEDs already onboard, making the project a cinch. It also comes with a MEMS microphone and a light sensor all ready to go. Thus, with a bit of code, [Alex] was able to create a timer activated by a loud noise, such as clapping. Once detected, the timer starts, flashing its LEDs to indicate time remaining. There’s also a nightlight feature, which activates when light levels decrease, making it easier to navigate the bathroom in the dark.

It’s a useful little project for these troubled times, and one that makes great use of everything onboard the Circuit Playground Express. Having everything included certainly does make projects come together quickly. You can even program it from your phone! Video after the break.

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LED Heart Beats With The Beholder

April 3, 2020 by Zoe Skyforest 9 Comments

Many a maker likes to use their craft to create gifts for loved ones. [Jiří Praus] was celebrating having been married for 5 years, and crafted this beautiful LED heart sculpture to commemorate the occasion.

The outer shell was created by first starting with a 3D printed heart shape. This was used as a form upon which the brass wire could be soldered together to form an attractive heart-shaped cage. Inside, an Arduino Nano is hooked up to a series of WS2812b LEDs. The LEDs are flashed in time with the heartbeat of the person holding the heart, thanks to a MAX30102 heartbeat sensor. There’s also a TP4056 charge module and a small lithium battery to provide power for the device.

Adding the heartbeat sensor really makes this project shine, forming a connection between the holder and the device itself. The tasteful craftsmanship of the brass design makes this an excellent gift, one we’re sure anyone would like to receive. We’ve seen [Jiří Praus] make the most of this artform before too, with projects like this stunning tulip or dead-bug Arduino. Video after the break. Continue reading “LED Heart Beats With The Beholder” →