Motorized Skateboard Controlled By Hand Gestures

August 17, 2013 by Mike Szczys 7 Comments

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This rough-looking contraption is a hand gesture controlled skateboard which [Aditya] built using parts on hand. So far the sensor for hand gestures is connected by a control wire, but he hopes to transition to an RF unit at some point in the future.

Having access to a couple of high torque brushless motors is what turned him onto the project. He hit up a couple of Mechanical Engineer friends of his to help assemble the chassis and then started on the electronics side of things. A breakout board for an ATmega16 is mounted on the corner of the deck. It monitors an accelerometer which acts as steering as well as throttle. The accelerometer had been abused in a previous project so he had to add an extra switch to bolster his available inputs. We were glad to hear that he also included a kill switch, since putting the control of those motors in the hands of a damaged accelerometer is a bit sketchy.

We remember seeing a similar trike design a few years back. That one powered a single rear wheel while this one powers two wheels and uses a caster for the third.

All Wheel Drive Motorcycle

August 12, 2013 by Mike Szczys 37 Comments

Take one look at the front fork of this dirt bike and you’ll notice that it’s not really a front fork at all. A custom front end replaces the traditional design in order to give this motorcycle all wheel drive. Look closely and you’ll see the chain that drives the front wheel. The swing-arm like addition lets the front end retain all of its suspension and steering and that’s where the project gets tricky.

We actually saw this thing in person at the monthly meeting of our local hackerspace: Sector67. [Martin Lawson] got his seven minutes of fame during the presentations (they use a prototype of this scoreboard to limit each presenter), and then was mobbed with a ton of interest afterwards. We were able to get a pretty good look at how the front drive works. It starts with an additional cog fastened beside the one that drives the chain for the back end. This feeds up through some tensioners and transfers out on the left side (from the rider’s perspective) of the front end. From here the rotational force is transferred to the right right and includes a U-joint to account for steering. The last chain goes straight down to the wheel.

The idea is that when the rear wheel loses traction you’re still being pulled by the front. This is illustrated well in the video after the break. [Marty] — who has a patent on the design — is trying to get some interest from manufacturers. He says the ability ride right through poor traction terrain make this a lot easier than a traditional dirt bike for beginners to ride. But it’s obvious the professionals are having fun on the thing as well!

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DIY 23mph+ Electric Skateboard

August 10, 2013 by Marsh 25 Comments

What’s the best way to get around NYC? If you asked [papo2110], he would probably suggest you build your own high-speed, long-range electric skateboard. You can’t cruise through any online maker community without tripping over a dozen e-vehicle projects these days. Nearly 18 months ago, even before the popular Boosted Boards Kickstarter, [papo2110] started piecing together a deck. His boards use a brushless outrunner motor, an RC car ESC (complete with brakes), and a chain drive to power him around Central Park at a top speed of 23mph.

The most impressive feat for this project, however, is the tireless revision through iterative design. The deck gets both an aluminum and a carbon fiber upgrade. Meaty 8S Headway LiFePo4’s replace a smaller 6S configuration. Even lights are added. As the build progresses, the board is pushing 27mph: with only one motor. Grab your helmet and motion-sickness pills and strap in for some videos after the break.

If four wheels are one too many and you want even more dangerous speeds, check out the E-trike build from a few months ago.

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The Hubless Horseman

August 10, 2013 by Marsh 31 Comments

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Of all the free parts up for grabs at a friend’s house, nobody wanted the scrap wheelchair wheels: including [Eric]. That is, of course, until he spontaneously decided to try something a bit crazy and take on a bizarre yet remarkably imaginative hubless wheel bike build.

After attaching the wheelchair’s rim and its affixed handrail to the rim on his bike, [Eric] mounted pairs of rollerblade wheels to a separate piece of metal that essentially act as bearings. As the build progresses, the bike is further refined. More rollerblade wheels, a giant sprocket, and a pile of machined aluminum pieces. The valve stem for the tire had to be relocated to allow the wheel to spin freely.

The finished product is a stunning bicycle, which [Eric] later revisited, updating the rollerblade wheels to precision-lathed plastic (specifically UHMWPE) rollers. Make sure you watch the video of the Hubless Horseman in action. If, for some reason, your only prior exposure to hubless wheels is the TRON light cycle or [Kirk’s] motorcycle from the Star Trek reboot, do yourself a favor and check out their inventor, Franco Sbarro.

Racing Telemetry On A Cockpit View

July 30, 2013 by Brian Benchoff 10 Comments

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[Martin] has a Lotus Elise and access to a track. Sounds like fun, huh? The only problem is that the dashcam videos he makes are a little bit boring. Sure, they show him flying around the track, but without some sort of data it’s really hard to improve his driving skills. After thinking about it for a while, [Martin] decided he could use his Raspberry Pi and camera module to record videos from the dashboard of his car, and overlay engine data such as RPM, throttle, and speed right on top of the video.

Capturing video is the easy part of this build – [Martin] just connected his Raspi camera module and used the standard raspivid capture utility. Overlaying data on this captured video was a bit harder, though.

[Martin] had previously written about using the Raspi to read OBD-II data into his Raspi. Combine this with a Python script to write subtitles for his movies, and he’s off to the races, with a video and data replay of every move on the track.

The resulting movie and subtitle files can be reencoded to an HD movie. Reencoding a 13 minute HD video took 9 hours on the Raspi. We’d suggest doing this with a more powerful compy, but at least [Martin] has a great solution to fix his slightly uninformative track videos.

Defcon Presenters Preview Hack That Takes Prius Out Of Driver’s Control

July 26, 2013 by Mike Szczys 66 Comments

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This one’s a treasure trove of CAN bus hacks that will scare the crap out of an unsuspecting driver — or worse. [Charlie Miller] and [Chris Valasek] are getting ready to present their findings, which were underwritten by DARPA, at this year’s Defcon. They gave a Forbes reporter a turn in the driver’s seat in order to show off.

You’ve got to see the video on this one. We haven’t had this much fun looking at potentially deadly car hacking since Waterloo Labs decided to go surfing on an Olds. The hacks shown off start as seemingly innocent data tweaks, like misrepresenting your fuel level or displaying 199 mph on the speedometer while the car is standing still. But things start to get interesting when they take that speed readout from 199 down to zero instantly, which has the effect of telling the car you’ve been in a crash (don’t worry, the airbags don’t fire). Other devilish tricks include yanking the steering wheel to one side by issuing a command telling the car to park itself when driving down the road. Worst of all is the ability to disable the brakes while the vehicle is in motion. Oh the pedal still moves, but the brake calipers don’t respond.

The purpose of the work is to highlight areas where auto manufacturers need to tighten up security. It certainly gives us an idea of what we’ll see in the next Bond film.

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Building A Bike For 100 Miles Per Hour

July 25, 2013 by Brian Benchoff 11 Comments

As a kid, [Tom] followed all the automotive land speed record attempts on the Bonneville Salt Flats. The cars used in these attempts were all built by guys in their garages, and as a bicycle frame builder, [Tom] is keenly aware of the land speed record for bikes. One thought leads to another, and [Tom] decided he would see how fast one of his frames could go.

Aside from a gigantic gear for his custom bike, [Tom] also needed a little help from a friend. The current land speed record on a bicycle was done by drafting behind a drag racer. [Tom] doesn’t have a drag racer, or a wide expanse of flat open ground in his native England, so he did the next best thing: drafting behind a Ford Zephyr on an abandoned WWII airstrip.

On the runway, [Tom] was able to get his bike up to 80 miles an hour. Wanting to see how fast he could go in ideal conditions, the bike was taken to the garage, put on a pair of rollers, and measured as it was brought up to speed. With a lot of effort, [Tom] was able to get up to 102 miles per hour, incredibly fast for something powered by human muscle.