Analysing 3D Printer Songs For Hacks

August 20, 2017 by Inderpreet Singh 8 Comments

3D printers have become indispensable in industry sectors such as biomedical and manufacturing, and are deployed as what is termed as a 3D print farm. They help reduce production costs as well as time-to-market. However, a hacker with access to these manufacturing banks can introduce defects such as microfractures and holes that are intended to compromise the quality of the printed component.

Researchers at the Rutgers University-New Brunswick and Georgia Institute of Technology have published a study on cyber physical attacks and their detection techniques. By monitoring the movement of the extruder using sensors, monitored sounds made by the printer via microphones and finally using structural imaging, they were able to audit the printing process.

A lot of studies have popped up in the last year or so including papers discussing remote data exfiltration on Makerbots that talk about the type of defects introduced. In a paper by [Belikovetsky, S. et al] titled ‘dr0wned‘, such an attack was documented which allowed a compromised 3D printed propeller to crash a UAV. In a follow-up paper, they demonstrated Digital Audio Signing to thwart Cyber-physical attacks. Check out the video below.

In this new study, the attack is identified by using not only the sound of the stepper motors but also the movement of the extruder. After the part has been manufactured, a CT scan ensures the integrity of the part thereby completing the audit.

Disconnected printers and private networks may be the way to go however automation requires connectivity and is the foundation for a lot of online 3D printing services. The universe of Skynet and Terminators may not be far-fetched either if you consider ambitious projects such as this 3D printed BLDC motor. For now, learn to listen to your 3D printer’s song. She may be telling you a story you should hear.

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Print A Flexible Keypad

August 15, 2017 by Al Williams 8 Comments

[Micah Elizabeth Scott] needed a custom USB keyboard that wrapped around a post. She couldn’t find exactly what she wanted so she designed and printed it using flexible Nijaflex filament. You can see the design process and the result in the video below.

The electronics rely on a Teensy, which can emulate a USB keyboard easily. The keys themselves use the old resistor divider trick to allow one analog input on the Teensy to read multiple buttons. This was handy, but also minimized the wiring on the flexible PCB.

The board itself used Pyralux that was milled instead of etched. Most of the PCB artwork was done in KiCAD, other than the outline which was done in a more conventional CAD program.

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DIY Dual Extrusion

August 14, 2017 by Al Williams 8 Comments

Dual extrusion 3D printers are not as uncommon as they used to be, but there are still a lot of single-extruder machines. [Paul Lang] wanted to refit his printer to take two MK8 extruders, and he documented his experience with a blog post that has a few good tips if you want to try it yourself.

[Paul] used Fusion 360 to design a holder for the extruders that would fit his printer. Since he had accidentally ordered a spool of pink PLA, the whole assembly is shocking pink — not subtle at all. He shares a few design tips about using PLA near the hot areas and making everything fit and level.

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Filaween 2.0 Is Go

August 14, 2017 by Elliot Williams 3 Comments

[Thomas Sanladerer] is at it again: testing all of the 3D-printer filaments that are fit to print (with). And this year, he’s got a new and improved testing methodology — video embedded below. And have a search for “filaween2” to see what he’s reviewed so far. There’s some sexy filaments in there.

We really love the brand-new impact strength test, where a hammer is swung on a pivot (3D printed, natch), breaks through the part under test, and swings back up to a measurable height. The difference in swing height reflects the amount of energy required to break the test piece. Sweet physics.

[Thomas] ran a similar few-month-long series last year, and we’re stoked to see it return with all the improvements. Here’s to watching oddball plastics melt!

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3DP Enigma Keyboard Improves On The Original

August 12, 2017 by John Baichtal 1 Comment

[Asciimation], who previously created an Enigma Machine wristwatch, decided to go all-in and make a 3D-printed Enigma machine. Not a perfect replica, but rather an improved version that works the same but doesn’t concern itself with historical accuracy. For instance, the current step involves building the keyboard. Rather than trying to re-create the spring-and-pin method of the original, he simply swapped in readily available, double-throw micro switches.

This project has a tremendous amount of fascinating detail. [Asciimation] did his research and it shows; he downloaded blueprints of the original and used hacked digital calipers to precisely measure each rotor’s teeth, so that it could be re-created for printing. He even re-created the Enigma font to ensure that his printed rotor wheels would look right–though in doing so he discovered that the original machine used one typeface for the keyboard, one for the wheels, and one for the indicator lamps.

We previously published [Asciimation]’s Enigma machine wristwatch project, where he simulated the functionality of an Enigma with an Arduino.

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Hackaday Prize Best Product Finalist: Shape Shifting Structures For Space

August 10, 2017 by Steven Dufresne 20 Comments

While [Elon Musk] and [Jeff Bezos] are working on getting us to Mars and the Moon, [Ronald Jaramillo] is working on building structures once we get there. To that end, he’s been developing the ZBeam, two rolls of links that zip together like a zipper to form a rigid beam.

Initially stored in a compact cube targeted to eventually fit in a CubeSat’s dimension’s, 100 mm x 100 mm x 100 mm, the beam emerges from within the cube and will be able to connect with other cubes to form rigid structures. His hope is that they can one day be made automatically from lunar or Martian regolith (loose surface dirt) munching machines. His current one has 160 mm sides and uses a servo hacked to turn continuously.

In his hackaday.io project logs he shows the trial and error he’s gone through to get to his current stage: experimenting with the links to form a more rigid beam, fine tuning the unreeling of the rolls of links to prevent jamming, adding a safety-ratchet-gear to the gearing to overcome speed issues, and more. He currently 3D prints as many connected sets of links as he can on his Prusa i3, and then manually connects sets together to make a longer chain, but he has his eye on the Printrbot Printrbelt for printing arbitrarily long chains in one piece.

You can see one pretty impressive iteration of the ZBeam in action in the video below and more is on his project page. In fact, the judges for the 2017 Hackaday Prize liked [Ronald]’s projects so much that they designated it as a Best Product finalist.

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3D Printing Flexible Surfaces Out Of Non-Flexible Material

August 5, 2017 by Donald Papp 15 Comments

Here’s some interesting work shared by [Ben Kromhout] and [Lukas Lambrichts] on making flexible 3D prints, but not by using flexible filament. After seeing a project where a sheet of plywood was rendered pliable by cutting a pattern out of it – essentially turning the material into a giant kerf bend – they got interested in whether one could 3D print such a thing directly.

Inspiration for the project was this laser-cut plywood.

The original project used plywood and a laser cutter and went through many iterations before settling on a rectangular spiral pattern. The results were striking, but the details regarding why the chosen pattern was best were unclear. [Ben] and [Lukas] were interested not just in whether a 3D printer could be used to get a similar result, but also wanted to find out what factors separated success from failure when doing so.

After converting the original project’s rectangular spiral pattern into a 3D model, a quick proof-of-concept showed that three things influenced the flexibility of the end result: the scale of the pattern, the size of the open spaces, and the thickness of the print itself. Early results indicated that the size of the open spaces between the solid elements of the pattern was one of the most important factors; the larger the spacing the better the flexibility. A smaller and denser pattern also helps flexibility, but when 3D printing there is a limit to how small features can be made. If the scale of the pattern is reduced too much, open spaces tend to bridge which is counter-productive.

Kerf bending with laser-cut materials gets some clever results, and it’s interesting to see evidence that the method could cross over to 3D printing, at least in concept.