Hacklet 41 – Prosthetics Projects

April 3, 2015 by Adam Fabio 8 Comments

Throughout human history, mankind has worked to enable those with disabilities. This applies especially to those who have missing limbs, either from injury or since birth. Every time technology improves, prosthetics improve along with the way. Unfortunately this now means prosthetics have become expensive systems. Hackers, makers, and engineers are working to make prosthetics more affordable, and more available to everyone. This week’s Hacklet focuses on some of the best prosthetics projects on Hackaday.io!

We start with [Open Bionics] and Affordable Bionic Hands For Amputees. The [Open Bionics] team are using 3D printers to bring the cost of a prosthetic arm and hand down from up to $100,000 USD to just $1000 USD. They’ve also reduced the time to create a custom device from weeks to just 5 days. The team’s current hand has five degrees of freedom, uses electromyography (EMG) for control, and weighs just 268 grams. [Open Bionics] discovered that many amputees are willing to trade off functions for a lighter weight device. Having a sensor and motor studded hand won’t help much if the wearer is worn out after just a couple of hours!

Next up is [yash.gajra56] and RE-ARM. RE-ARM is a prosthetic arm project which aims to help both those who have lost limbs, and those with full or partial paralysis of a limb. Movement is provided by radio control style servos. Control is via voice commands and Bluetooth from a cell phone. [Yash] has incorporated feedback into RE-ARM by using flex sensors. Processing is handled by an Arduino. We like the low-cost, low tech approach RE-ARM uses. We’d love to see everyone have access to a 3D printer, but unfortunately the world isn’t there quite yet. RE-ARM uses readily available components to build a functional prosthetic. Nice work [yash]!

[OpenBionics] brings us Affordable Prosthetic Hands. No, you didn’t read that name wrong. There are two “Open Bionics” on Hackaday.io! This [OpenBionics] team has no space, and is based in Athens, Greece. The other [Open Bionics] team does have a space between the words, and is based in Bristol in the United Kingdom. We’re hoping the two groups can come together and collaborate now that they’re both using Hackaday.io. This [OpenBionics] team is working on prosthetic hands, in the sub $200 USD price range. The team has come up with a novel thumb design which provides nearly full functionality with only one rotating joint. [OpenBionics] also allows their users to selectively lock digits, which allows for up to 144 different grasping postures.

Finally we have [Daniel Mead] with Third World Medical Equipment (Arm). [Daniel] created this project as an independent study back in high school. The idea is create a simple arm with a gripper out of cheap or freely available items. The gripper is fashioned from a bicycle brake. The fitting system is especially novel. [Daniel] used an old soda bottle to create a custom mold for the amputee’s residual limb. Plastic bottles are generally made of polyethylene terephthalate, or PET, a thermoplastic. [Daniel] placed a wet sock over his arm, and a plastic bottle over the sock. Holding the plastic bottle above a fire created enough heat to shrink the bottle to his arm. the sock provided room for padding, and insulated him from getting burned during the molding process.

Not satisfied? Want more prosthetics? Check out the Prosthetics list over on Hackaday.io! If any of these projects inspire you, don’t forget that prosthetics are a great starting point for an entry in The Hackaday Prize!

That’s about all the time we have for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Cutting SMT Stencils With A Laser

April 3, 2015 by James Hobson 22 Comments

Prototyping your own PCBs? At a loss for how to apply your SMT electronics? Well — do you have access to a laser? [Felix] shows us a definitive way to use a laser cutter to engrave SMT stencils with ease.

The real trick here is to engrave — not to cut. Typically if you’re using enough power to cut straight through the plastic, you’re going to get melting and burning of the edges — which won’t work well for a SMT stencil. So what [Felix] found is to engrave at approximately 20-30W @ 400-450mm/s. He’s using Mylar as the material.

The results are pretty awesome — but if you’re without a laser, he also has an excellent tutorial on DIY metal SMT stencils by chemically etching soda can metal!

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8-bit Digital Photo Gun

April 3, 2015 by Brian Benchoff 23 Comments

One of the first popular mass-produced digital cameras was the Game Boy camera, a terrible black and white image sensor stuck inside a highly modified Game Boy cartridge. With a Game Boy, the camera, and the Game Boy printer, it was able to produce low-resolution but still surprisingly usable images. Combine all these parts together with the best of hacker art from [vtol] and what do you get? The Game Boy Instant Photo Gun.

There aren’t many details for this build, but it looks like this is an uncased Game Boy Brick, a Game Boy camera, and Game Boy Printer assembled into something that looks dangerous and won’t get past a TSA checkpoint. That might be fixed by repurposing an old NES zapper.

We’ve seen [vtol]’s work before with a machine that probably doesn’t steal your credit card info, a levitating speaker, and something that doesn’t reference [Tarkovsky] enough. This build is right up there with the rest of them.

Thanks [Itay] for the link.

Hack A Lock, Get A Free Car?

April 3, 2015 by James Hobson 62 Comments

No, we’re not talking about any lock, or car for that matter. The creators of Loxet are so confident in their product, a smart lock for your car, they’ve issued a challenge to the world. If you can defeat it, you can keep the car — sadly the car isn’t anything special though.

The device, after installed on your vehicle, gives you a taste of the premium lifestyle of fancy push-to-start vehicles. It automatically unlocks your vehicle when you come near with your cellphone, and only your cellphone. It also has the option to give access to friends and family using an invite system. It controls ignition access, and works as a proximity lock.

The car is located at ul. Straszewskiego 14 in Krakow. If you’re not from Poland, [Matt] recommends you team up with a local to try your hack. The alternate prize (if you’re not from Poland or don’t want the car) is $2000.

The car is just sitting there. We’d love to see some 1st person attempts from any of our Polish readers living in Krakow! It is currently set to unlock and lock every 10 minutes. You might be able to get into the vehicle — but will you be able to take it? Let us know!

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Tube Map Radio And Denki Puzzles

April 2, 2015 by Anool Mahidharia 5 Comments

Sometimes, awesomeness passes us by and we don’t notice it until a while later. This is from 2012, but it’s so friggin’ insane we just have to cover it even if it’s late. Yuri Suzuki is an installation artist who designed the Tube Map Radio and Denki Puzzles.

The Tube Map Radio is inspired by a diagram created by the original designer of the London Tube map, Harry Beck, which shows the lines and stations of the London Underground rail network as an annotated electrical circuit. Iconic landmarks on this map are represented by components relating to their functions, including a speaker where Speaker’s Corner sits, battery representing Battersea Power Station and Piccadilly Circus marked as Piccadilly Circuit. The work was commissioned by the Design Museum London, and the PCB layout was done by Masahiko Shindo (Shindo Denki Sekkei). The idea was to bring the electronics out of the “black box” and not just display it, but to have it laid out in a fashion that people could try to understand how it really works.

The other project called Denki Puzzles is equally remarkable. It’s a kit meant to teach electronics, using a set of snap-fit components. But instead of having all “bricks” or units of the same shape, the Denki Puzzles are a collection of printed circuit board pieces whose form indicate a particular function. Fit the pieces together as a sort of physical circuit diagram and you’ll be able to build working electronics. For example, the LED unit looks like a 8 pointed star, and the resistance unit looks like a resistance symbol. Check out some pictures and a video after the break

Photo’s Credit : Hitomi Kai Yoda.

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The Best Project We Never Did Yet

April 2, 2015 by Brian Benchoff 97 Comments

Back when [Caleb] was around here at Hackaday, he was tasked with making a few YouTube videos. His Portal Gun got 1.6 Million views, and we got a takedown request because of this video even though that company was more than willing to use [Caleb] as a guinea pig at CES.

This post is not about those videos. This post is about the best project we never did yet.

The grand plan for The Best Project was a zombie survival van. It’s exactly what you think it is: a van armored and armed for driving through a herd of walkers. Proposed mods included a cow catcher and roof rack, a motorized turret, a poofer (propane tanks shooting fire from underneath the van), a bartender that launches molotov cocktails, and a beautiful little contraption called an ankler. The Ankler is just a pair of chainsaws that fold out from under the van.

The base vehicle would be a 60s VW bus. [Caleb]’s a big fan of aircooled stuff, and if you think about it, 60s VWs are pretty good for the zombie apocalypse. If you’re doubting that, just ask how many tools it would take to change out the engine in your car.

Although the dream of a Hackaday aircooled zombie apocalypse van died when [Caleb] left, that doesn’t mean we’re still not considering an official Hackaday ride. All of this is still in the planning stages, but we have a few ideas; the first, and biggest, is a mobile hackerspace on a trailer. This would be a standard semitrailer, loaded up with tools, 3D printers, a laser cutters, and a couch. It would be the perfect thing to load up with swag and haul to events.

We’re considering another more sensible vehicle, and right now the top contender is an early 2000s Astro or Safari cargo van. Yes, I know what you’re thinking: the coolest vehicle we could come up with is a minivan. There’s actually some logic to this, so hear me out.

The Astro/Safari shares a lot of parts with the S10, and that means parts are everywhere. The Astro has an AWD variant, and with a 4″ lift, upgraded suspension and big, knobby tires the Hackaday van would be very, very fun to take out into the desert. It can haul eight foot sheets of plywood, they’re cheap, everywhere, and they just don’t die.

While the best idea right now is an Astro van, we’re also considering other AWD vehicles: an AMC Eagle would be cool, and I think RedBull has a few Suzuki X-90s sitting around. An M35 Deuce And A Half would be fun. A US Mail Truck would probably last forever, and if we go with the semi-trailer concept we would probably want a smaller vehicle on site wherever we park the truck. Current options for this parasitic vehicle include a Nash Metropolitan, a Trabant, a Citroen 2CV, a Renault Dauphine, a Lada, or a Yugo. Yes, they’re all ridiculous but they’re small and can fit in the back of a semi trailer.

It’s still an idea we’re throwing around, but we really need a reason to have a van before we go out and build a hackaspace on wheels, a zombie survival van, or something to launch off some sweet ramps. We don’t go to that many events, and driving a crappy old van across the country a few times a year sounds like fun but surely isn’t.

You can check out [Caleb]’s pitch video for the zombie survival van below.

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Manual Data Recovery With A Hex Editor

April 2, 2015 by Brian Benchoff 26 Comments

Let’s say you use an SD card-base portable audio recorder for work – doing an interview, perhaps. Things go well until one day, you turn the recorder off before stopping the recording. Without pressing that big red Stop button, the file doesn’t close, and you’re left with a very large 0kB file on the SD card. How do you get it back? There are tools that will do it for you, but they cost money. You can do it yourself with a hex editor, though, and it’s actually pretty easy.

The software required for this feat of data recovery is Roadkil’s Disk Imager to dump all the bits on the SD card to an image file, the free version of ISO Buster to show the block addresses and length of each file, and the hex editor of your choice. The process starts as simply an experiment for hot to create an MP3 file by cutting and pasting bits into a hex editor. A good file was found in the hex editor, copied to a new file, and played. Everything works so far; great.

For the actual data recovery, a spreadsheet was created to make an educated guess as to where the lost file should be. Starting at this address, about 90MB of data was copied into a new hex editor window. This is where the recovery hit a snag. Because the SD card was plugged into a Mac before, a bunch of data was written on the card. This went into the first available place on the disk, which just happened to be the header of the lost MP3 file.

That’s not a problem; there’s already the header from an MP3 file sitting in a hex editor from the first experiment to see if this was possible. By copying a few hundred bytes to the front of the lost file, the file was corrected just enough that an MP3 player could reconstruct the file.

It’s not perfect – the first fifty seconds of the interview was garbled. The rest of the interview was saved, though, and that’s much better than losing the entire thing. Thanks [Lewin] for sending this one in.

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