Kids Electric Mini Goes Brushless, Pops Wheelies

June 10, 2015 by Adam Fabio 40 Comments

[ThatHpiGuy] had a problem. He wasn’t impressed with the performance from his kids’ electric-powered Mini. The 6 volt system was anemic at best, and was just begging for an upgrade. Pulling off the seat and checking the undercarriage, [ThatHpiGuy] realized the motor and gearbox were a perfect fit for the Turnigy 2300 Kv motor from his R/C short course truck. A couple of screws later, and he had the fastest ride-on toy on the block. Since this was a quick hack, [ThatHpiGuy] kept the truck’s R/C receiver, electronic speed control, and 2 cell LiPo power setup intact. The result is a cooperative system where he controls the throttle via R/C, and his kids control the steering.

That steering is still a bit of an issue though. Like many kid toys, the Mini only has one drive wheel, in this case the right rear. If [ThatHpiGuy] pours on the power a bit too quickly, the single wheel either spins or forces the car into a hard left turn. Aside from that, it looks like both [ThatHpiGuy] and his children are having a ball with this hack. The car will even pop a wheelie from a standing start! You’ve got to see it after the break.

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Anodized aluminium phone mount for a bike

Anodized Phone Mount For Your Bike

June 5, 2015 by Eric Evenchick 17 Comments

There’s a slew of apps out there for tracking your bike rides. If you want to monitor your ride while using the app, you’ll need it securely affixed to your bike. That’s where [Gord]’s No Dropped Calls build comes in. This aluminium mount was hand milled and anodized, which gives it a professional finish.

The mount consists of 3 parts which were machined out of stock 6061 aluminium. The plans were dreamt up in [Gord]’s head, and not drawn out, but the build log gives a good summary of the process. By milling away all of the unnecessary material, the weight of the mount was minimized.

Once the aluminium parts were finished, they were anodized. Anodization is a process that accelerates the oxidization of aluminum, creating a protective layer of aluminium oxide. [Greg] does this with a bucket of sulphuric acid and a power supply. Once the anodization is complete, the part is dyed for coloring. If you’re interested, [Gord] has a detailed writeup on home anodization.

The final product looks great, puts the phone within reach while biking, and prevents phone damage due to “dropped calls.”

Do Not Try This At Home: A Jet Powered Go Kart

May 17, 2015 by James Hobson 42 Comments

[Colin Furze] is at it again. This time he’s built a freaking jet-engine powered go kart.

In case you’re not familiar with [Mr. Furze], he’s no stranger to building high-speed vehicles, like the fastest baby stroller in the world. And he’s also got a bit of an obsession with pulse jet engines. He’s even made one out of a toilet roll holder. He was a plumber — but now he’s one of the best mad scientist YouTube creators around. We just hope he doesn’t kick the bucket too soon with one of his extreme projects, because his safety tie probably won’t save him!

This month’s project is no exception — he’s strapping his giant pulse jet engine he used to fart on France onto the frame of a tiny go kart. “As you can see the jet to kart ratio is pretty good”. No kidding — the engine has gotta be 2.5 times as long as the go kart’s frame!

Stick around after the break to see him risk his neck for our own amusement.

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Direction Projection Is A Beacon In The Night

May 13, 2015 by Adam Fabio 35 Comments

Navigating with your phone can be a hassle: the phone displays a tiny map that you’re never supposed to look at while driving, but of course you do. [Mikeasaurus] has the ultimate solution: Direction Projection! Mike has created an augmented reality system with no glass heads-up display, and no goggles ala Microsoft Hololens. The road ahead is his canvas. A standard projector mounted atop his car displays maps and turn indicators, all from his phone. Linking the phone and projection system would normally involve HDMI or analog video cables strung through the roof. [Mikeasaurus] simplifies that by using a Chromecast, which allows him to stream his phone’s screen over WiFi.

The projector itself is the HD25-LV, a 3500 Lumen model from Optima. the HD25-LV is capable of 1080p, though in this situation, brightness is much more important than resolution. [Mikeasaurus] mounted the projector along with a gel cell battery and 900 watt DC to AC inverter to power it. A mobile WiFi hotspot fills out the rooftop kit. Leaving an expensive setup like that on top of a car is a recipe for disaster – be it from rain, rocks, or theft. [Mikeasaurus] thought ahead and strapped his setup down inside a roof mounted cargo box. A plastic covered hole in the front of the box allows the projector to shoot down on the road while protecting its lens. We’d want to add a vent and fan to ensure that projector gets a bit of airflow as well.

On the road, the system actually works. Understandably, it’s not going to work very well during the day, but at night the system really shines! Just don’t tailgate – you wouldn’t want the driver in front of you to know exactly where you’re going, would you?

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PicoRico Hacks String Encoder For Bike Suspension Telemetry

May 12, 2015 by Mike Szczys 26 Comments

It’s simple, it’s elegant, and it works really really well. The PicoRico team built a telemetry system for a downhill bike. Off the top of your head how would you do this? Well, telemetry is easy… just add an IMU board and you’re golden. They went beyond that and have plans to go much further. In fact, the IMU was an afterthought. The gem of this build is a sensor that may go by several names: string encoder, draw wire sensor, stringpot, etc. But two things are for sure, they planned well for their hackathon build and they executed on that plan. This landed them as first-runners-up for the top award at the 2015 Disrupt Hackathon in New York, and the winners of the top Hackaday award at the event.

[Chris], [Marek], and [Dorian] wanted to log all the telemetry data from [Chris’] downhill bike. One of the biggest challenges is to measure the force absorbed by the suspension on the front fork. The three had seen a few attempts at this before. Those used a retractable wire like what holds keys to a custodian’s belt, mated with a potentiometer to measure the change. This is where the term stringpot comes from. The problem is that your resolution and sensitivity aren’t very reliable with this setup.

That is a sensor problem, not a mechanical problem so they kept the retractable reel and replaced the pot with a much more reliable part. In its place an AMT203 absolute position sensor provides an epic level of sensing. According to the datasheet (PDF) this SPI device senses 12 bits of rotation data, can be zeroed over the SPI bus, and is accurate to 0.2 degrees. Unfortunately we didn’t get a good up-close shot of the installation but it is shown in the video. The encoder and retractor mount above the shocks, with the string stretching down to the skewer. When the shocks actuate, the string extends and retracts, turning the absolute encoder. Combine this with the IMU (and two other IMUs they plan to add) and you’ve got a mountain of data to plot and analyze. The videos after the break show a demo of the string encoder and an interview with the team.

They came to play

It’s worth noting that the PicoRico team were in this to win it. They packed heavy for the 20-hour hackathon. Here’s a picture of all the gear they brought along with them to the event… in addition to the bike itself.

We see a solder station, Dremel (with drill press), impact driver, tap and die set, extension cords, boxes full of electronics, and more. This type of planning breaks down barriers often faced at hardware hackathons. You can download a software library; you can’t download a tool or building material that nobody has with them. This is the same lesson we learned from [Kenji Larsen] who, as part of his mentoring at the event, brought a mobile fabrication facility in a roller bag.

If you start getting into hackathons, and we hope you will, keep this in mind. Brainstorm as much as you can leading up to the event, and bring your trusted gear along for the ride.

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LEDs Strips Tell You The Trains Aren’t Running

May 8, 2015 by Bryan Cockfield 15 Comments

[James] is a frequent user of the London Underground, a subway system that is not immune to breakdowns and delays. He wanted a way to easily tell if any of the trains were being disrupted, and thanks to some LEDs, he now has that information available at a glance without having to check a webpage first.

Inspired by the Blinky Tape project at FT Engineering, [James] thought he could use the same strip of addressable LEDs to display information about the tube. A Raspberry Pi B+ gathers data from the London Underground’s TfL API and does a few calculations on the data. If there is a delay, the LEDs in the corresponding section of the strip will pulse, alerting the user to a problem with just a passing glance.

The project is one of many that displays data about the conditions you’ll find when you step outside the house, without having to look at a computer or smartphone. We recently featured an artistic lamp which displays weather forecasts for 12 hours into the future, and there was an umbrella stand which did the same thing. A lot is possible with LEDs and a good API!

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Bicycle-Powered Wimshurst Machine

May 4, 2015 by Bryan Cockfield 16 Comments

A lot of great pieces of real technology were inspired (or, at least, look like) pieces of technology from science fiction of the past. Like the smartphones of today have a surreal resemblance to the Star Trek communicators of the 60s, [Steve] took inspiration from a story about a bicycle racing in space and set out to make his own.

In the story, the bicycle wheels are replaced by electrostatic generators that power a type of (fictional) ion drive. Since an ion drive wouldn’t add much thrust to a bicycle operated on the Earth, [Steve] used the electrostatic generator he built to create a sparking light show. The generator is called a Wimshurst machine and has two counter-rotating discs which collect charge. The charge is dissipated across a spark gap which is placed where the bike light would normally go.

We don’t know if the sparks from the Wimshurst generator are enough for a proper headlight, but it’s definitely a cool effect. [Steve] also points out that it might also work as a bug zapper, but either way you should check out the video after the break to see it in action! While it’s not quite a tricorder it’s still a pretty impressive sci-fi-inspired build, and something that’s definitely unique in the bicycle realm.

There’s quite a collection of these Wimshurst projects beginning to come together. Here’s one made using a trio of soda bottles, and another example which used 3D printing.

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