MIT students Grant Jordan and Kyle Vogt found themselves in possession of a high-security safe -- the S&G 8400, a class-1 safe of the sort formerly used to store classified documents. They wanted to open it, but they lacked the combination and were unable to crack it using the sort of techniques that work on lesser strongboxen. So they build a safecracking robot that autodialled combination after combination (the robot excluded "impossible" combinations that couldn't be set due to material limitations of the mechanism, which substantially reduced the keyspace). They eventually opened the safe, but didn't find anything interesting in it.
We used a custom stepper motor to rotate the dialer head. The dialer head transmits torque to the dial via a piece of heavy duty surgical tubing. The stepper motor we chose has more than enough resolution to implement our algorithm, but it's not quite as fast as it could be. Stepper motors have an extremely high "holding torque", which is ideal in this situation since the dial must be held in place while the butterfly knob is being turned.
The head also contains an RC servo motor with a machined knob to mesh with the butterfly knob. This setup enables independent rotation of both the dial and butterfly knob. The stepper motor shaft is also connected to a high resolution optical encoder for position feedback. The encoder is mainly used to detect when safe is successfully opened. The torque required to open the safe when the correct combination is entered is much higher than the maximum torque of the stepper motor, so the encoder is programmed to report when the position error exceeds a certain threshold. Basically, the stepper motor stalls and the encoder flips out if the safe actually opens.
Behold, the Blue Marlin, a “semi-submersible heavy lift ship” that is capable of hoisting and transplanting other, full-sized ships (that is ships as big or bigger than a US Destroyer-class vessel) all around the oceans.
Mister Alphabet is an action-figure designed to cleverly bend and contort into every letter of the Latin alphabet; the website is long on trademark warnings and arty Instagram photos, but short on details, like, “Is this an object of commerce?” and “If so, where does one buy it?” (via Kottke)
Phone chargers usually only deliver a few volts of juice at a feeble amperage, but they’ll deliver a lot more if you give them the chance. The BBC writes that a UK man died in the bathtub after being shocked by a charger connected to an extension cord. Richard Bull, 32, died when his iPhone […]
The Lightning port has thus far resisted the cruel fate that befell the headphone jack, and despite rumors that it may be disappearing come iPhone 8, for the present and foreseeable future, Lightning cables are a hot commodity for iPhone users. As such, we must make do in this strange time in which long, glorified […]
All the filters in the world won’t save your smartphone pics from a shaky hand. To really step up your mobile photography game, you’ll need some kind of mount to hold it steady. You could buy a smartphone attachment for a conventional camera tripod, but who wants to carry that kind of gear everywhere they […]
The forced transition from analog to digital TV signals was probably met with relative indifference from people with Netflix subscriptions and the “I don’t even own a TV” snoots. But anyone living in the vast swaths of the country that don’t have guaranteed high-speed internet, broadcast TV is a perfectly valid (and 100% free) way […]