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

ODB

[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.

Continue reading “Defcon Presenters Preview Hack That Takes Prius Out Of Driver’s Control” →

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.

Wooden Flatbed Truck Conversion

July 23, 2013 by Mike Szczys 55 Comments

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This pickup truck to flatbed conversion is very impressive. [Caswell_Etheredge] says he was channeling his inner redneck. That must mean rednecks in his area are craftsmen of the highest caliber.

He wanted a bit more flexibility on the size and shape of the cargo he was able to haul. Just six lag bolts held the original stamped steel bed on the truck. A bit of work with a pipe and a breaker bar did the trick. A mess of packed on mud and grime was there to greet him. After chipping, vacuuming, and power washing the underbody he gave it a fresh paint job using an undercoating product.

From there the wood flatbed build starts, and he’s not messing around with scrap wood. What you can see of the bed is fashioned from cedar and ipe. The underpinnings which fasten to the frame with those same six lag bolts are pressure treated 2×4 boards. The 4×6 bumper includes the license plate and lights for it. Brake and turn signals are built into the bed along with cleats for easy fastening of a tarp or to secure the cargo.

[via Reddit]

DIY Airbag, Explosions Included

July 14, 2013 by Brian Benchoff 16 Comments

AnAirbagSavedMyLife

Your car’s airbag is one of the major engineering accomplishments of the auto industry. In an accident, a whole host of processes must take place in sequence to keep your face from slamming into the steering wheel, and everything must happen in just a fraction of a second. [Steve] over at Make thought it would be a cool idea to discover what actually goes in to saving a life with an airbag and decided to build his own.

The electronics of the build consisted of an accelerometer and an Arduino. A lot of research, development, and experimentation has gone into the algorithms that trigger airbags, but [Steve] decided to keep things simple: when a sudden acceleration is detected, set off a small charge of black powder.

The airbag itself is ripstop nylon reinforced with canvas, contained in a small wooded box fitted with hinged doors. All these components are put on wheeled aluminum test rig, manned with a honeydew melon crash test dummy, and pulled into a short wall at a few miles per hour.

Despite [Steve] not putting hundreds of thousands of man hours into the development of his airbag – unlike the ones you’ll find in your steering column – his device actually worked pretty well. While not a complete success, he did manage to come up with something that both looks and acts like the familiar device that has saved countless lives.

Human Powered Flight Extravaganza

July 13, 2013 by Brian Benchoff 18 Comments

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In case you haven’t heard, the Sikorsky Prize, an aeronautical challenge to build a human-powered helicopter that can hover at three meters for a full sixty seconds, has been claimed. This incredibly difficult engineering feat was accomplished by AeroVelo, along with a lot of help from the University of Toronto and a host of companies involved in the design and manufacture of rotorcraft. This prize has stood unclaimed for thirty years, and it’s not from lack of trying; in the 80s and 90s, universities in Japan tried their hand at the challenge, and recently a team from the University of Maryland had a go at it.

But as far as human-powered flight goes, a helicopter is just about the least efficient way to get off the ground. Helicopters need power to provide their own lift and thrust, whereas airplanes only need to generate some forward momentum.

From the bicycle-powered crossing of the English channel in 1979, human-powered flight has come a long way, so far that next the Royal Aeronautical Society will be hosting the Icarus Cup 2013. It’s a competition where teams of human-powered aircraft enthusiasts will compete in challenges measuring distance, speed, endurance, and landing accuracy.

No, it’s not an ornithopter from Da Vinci’s notebook, but human pectoral muscles aren’t powerful enough for that anyway.

Thanks [DainBramage1991] for sending this one in.