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.
A flashlight review that begins with the promise “I’m about to hike through a remote canyon to an abandoned mine, and I gotta tell you there’s a storm raging outside” should end on an interesting note, and this one does. [via] Disturbing, strange sounds. That’s exactly what I caught on video while filming and documenting […]
Reflectacles, the hyper-reflective Ray Ban-style $75 glasses frames that Scott Urban is Kickstarting have a new feature: now you can get ones doped with materials that reflect the infrared light that CCTVs kick out to let them capture images in low light, which blind cameras’ sensors. Cool!
Typewriter historian Martin Howard (previously) writes, “I was able to pick up a rare and exquisite Waverley typewriter (1896) this summer in Scotland and have just the other day posted it to my website all cleaned and ready to show.”
The ARMOR-X Mini Flexible Phone Tripod is a smartphone tripod that is designed with flexible legs to rest on virtually any type of surface. Other tripods have proved useless unless I conveniently have a flat surface in front of me, which is why this particular tripod was appealing enough to try out. The ARMOR-X is compact and easy […]
You don’t need to get an advanced degree and take out massive loans to become a coder. This bundle of 10 courses was designed to teach anyone to code at home for less than it costs to go out for dinner. I was particularly impressed with this new 2017 bundle because it includes courses on […]
Five Star Christmas Tree Co is providing the easiest way yet to decorate for the holidays. This company will actually deliver a Christmas tree or wreath straight to your front door for a reasonable price.This direct to your door service includes your choice of Fraser fir trees, ranging from 3 to 7 feet tall. So whether you live […]