A 3D Printed Cryptex

April 15, 2014 by 9 Comments

Once you’ve dialed in your 3D printer calibration settings, you enter the phase of printer ownership where you’re eager to show off what you can make, and you’re sure to impress with [pjensen’s] 3d printed cryptex spinning around in your hands.

If you’re a regular reader of our 3D Printering column, then the behind-the-scenes screengrabs should look familiar: [pjensen] used Autodesk Inventor to sculpt the shapes, staring with the cryptex’s individual rings. After embossing the alphabet across each ring, [pjensen] adds slots into the inner loops for pins to slide through. An outer chamber holds the rings in place and prohibits access to the interior chamber, which is held in place on both sides by an end cap.

Lining up the rings to spell the correct word allows the inner chamber to slide free of the whole assembly, revealing whatever goodies may lie inside. You can follow [pjensen’s] step-by-step guide to build your own cryptex, or just download his model and start printing.

OLED display, blue LED and Smartcard

Developed On Hackaday: Olivier’s Design Rundown

April 15, 2014 by 16 Comments

The Hackaday writers and readers are currently working hand-in-hand on an offline password keeper, the Mooltipass. A few days ago we presented Olivier’s design front PCB without even showing the rest of his creation (which was quite rude of us…). We also asked our readers for input on how we should design the front panel. In this new article we will therefore show you how the different pieces fit together in this very first (non-final) prototype… follow us after the break!

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Step Into The Ring With Fight Coach

April 15, 2014 by 5 Comments

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As MMA continues to grow in popularity, the competition is getting tougher. There’s always someone else out there who’s training harder and longer than you are. So how do you get the advantage over your competitors? More push-ups? Sit-ups? Eat more vegetables? What about installing custom 2 by 1 inch, 5 gram PCB’s armed with an ATmega32U4, a MPU-6050 6 axis accelerometer and an RN-41 Bluetooth module into each of your gloves? Now that’s what we’re talking about.

[Vincent] and [Jooyoung] of Cornell joined their classmates in turning out another cool piece of electrical engineering. Fight Coach records data from the fighter’s gloves so that it can not only be analyzed to improve performance, but also interact with the fighter in real-time.  Though not quite as immersive as some fighter training techniques we’ve seen, Fight Coach might just give a fighter a slight edge in the ring.

Fight Coach offers 3 modes of training: Defense mode, Damage mode and Free-Training mode. As usual with Cornell projects, all code, schematics and a wealth of information on the project is just a click away. And stick around after the break for a video demonstration of Fight Coach.

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Retrotechtacular: The Cryotron Computer

April 15, 2014 by 14 Comments

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Have you ever heard of a Cryotron Computer before? Of course not. Silicon killed the radio star: this is a story of competing technologies back in the day. The hand above holds the two competitors, the bulkiest one is obviously the vacuum tube, and the three-legged device is what became a household name. But to the right of that tube is another technological marvel that can also be combined into computing machines: the cryotron.

[Dudley Allen Buck] and his contributions to early computing are a tale of the possible alternate universe that could have been cryotrons instead of silicon transistors. Early on we find that the theory points to exotic superconductive materials, but we were delighted to find that in the conception and testing stages [Buck] was hacking. He made his first experimental electronic switches using dissimilar metals and dunking them in liquid helium. The devices were copper wire wrapped around a tantalum wire. The tantalum is the circuit path, the copper wire acts as the switch via a magnetic field that alters the resistance of the tantalum.

The name comes from the low temperature bath necessary to make the switches work properly. Miniaturization was the key as it always is; the example above is a relatively small example of the wire-wound version of the Cryotron, but the end goal was a process very familiar to us today. [Buck] was searching for the thin film fabrication techniques that would let him shoe horn 75,000 or more into one single computing platform. Guess who came knocking on his door during this period of his career? The NSA. The story gets even more interesting from there, but lest we rewrite the article we leave you with this: the technology may beat out silicon in the end. Currently it’s one of the cool kids on the block for those companies racing to the quantum computing finish line.

[Thanks Frederick]

Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.

Automated Bed Leveling For 3D Printers Is Now Solved

April 15, 2014 by 39 Comments

The latest and greatest feature for 3D printers – besides being closed source, having no meaningful technical specs, and being on track towards pulling in $10 Million on a Kickstarter – is automated bed leveling. This amazingly useful feature makes sure your prints have proper adhesion to the bed, reduce print errors, and put even inexpensive printers into the realm of extremely expensive professional machines. Automated bed leveling has been extremely hard to implement in the past, but now [Scottbee] has it figured out with a working prototype on his Makerbot Replicator 2X.

Earlier attempts at automated bed leveling used some sort of probe on the tool head to measure the build plate, calculate its flatness and orientation in space, and compensate for any tilt in software. [Scottbee]’s solution to the problem took a different tack: instead of trying to compensate for any odd orientation of the build surface in software, he’s simply making the bed level with a series of springs and cam locks.

[Scottbee]’s device levitates the build plate on three springs, and replaces the jack screws with three “gimballing pins” and pin locks. With the pin locks disengaged, the bed plate is pressed down with the printer’s nozzle. By moving the extruder across the build plate and locking the pins in place one by one, [Scottbee]’s device defines the plane of the build plate along three points. This makes the build platform parallel to the extruder nozzle, and also has a nice benefit of setting the distance from the build platform to the nozzle precisely with incredible repeatability.

The mechanics of locking the three gimballing pins in place  only requires a single DC gear motor, driven by an extra fan output on the Makerbot’s electronics. It’s simple, and with a bit of rework, it looks like most of the device could also be 3D printed.

An awful lot of RepRaps and 3D printers out there already use three points to attach the build plate to a frame. With a little bit of effort, this same technique could be ported and made a bit more generic than the Makerbot-based build seen above. It’s amazingly simple, and we can’t wait to see this applied to a normal RepRap.

Thanks [Josh] for the tip.

Extracting Gesture Information From Existing Wireless Signals

April 15, 2014 by 16 Comments

A team at the University of Washington recently developed Allsee, a simple gesture recognition device composed of very few components. Contrary to conventional Doppler modules (like this one) that emit their own RF signal, Allsee uses already existing wireless signals (TV and RFID transmissions) to extract any movement that may occur in front of it.

Allsee’s receiver circuit uses a simple envelope detector to extract the amplitude information to feed it to a microcontroller Analog to Digital Converter (ADC). Each gesture will therefore produce a semi-unique footprint (see picture above).  The footprint can be analyzed to launch a dedicated action on your computer/cellphone. The PDF article claims that the team achieved a 97% classification accuracy over a set of eight gestures.

Obviously the main advantage of this system is its low power consumption. A nice demonstration video is embedded after the break, and we’d like to think [Korbi] for tipping us about this story.

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The Egg-Bot Gets A Little Wax Stabby

April 15, 2014 by 13 Comments

eggbot

With Easter just around the corner, [Windell and Lenore] over at Evil Mad Scientist Laboratories have come out with a new upgrade for their Egg-Bot. It’s called the Electro-Kistka and it allows your Egg-Bot to do wax-resist egg dying — in the same style as Ukranian Pysanky.

This isn’t the first time someone’s strapped a kistka to an Egg-Bot, but after seeing how much fun their customers were having, [Windell and Lenore] decided to make their own. It consists of two main components, a heater assembly that attaches to the Egg-Bot’s arm, and a power control board. To apply the wax they are using a kistka tip (looks like a soldering iron tip with a hole through it) which feeds molten wax onto the egg through capillary action.

It works almost exactly the same as the regular Egg-Bot arm, but allows you to dye your eggs with a very stark contrast as the wax repels dye perfectly. Just take a look at the following intricate designs.

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