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.
Craiglist has something wonderful on it: a vast collection of more than 600 vintage Smith-Corona typewriters, including accessories and marketing literature. Yours for a hundred grand. My collection consists of over 600 typewriter items including the company’s first typewriter in the 1880’s to one of the company’s last typewriters in 2000’s and all models in […]
We’re huge fans of portable power gadgets, but this one isn’t going in my pocket to help me keep my phone topped up after lunch. Anker’s Powerhouse is the size and weight of a concrete construction brick, and at $500 and 120,000mAh, by far their largest power pack yet. It’ll charge your laptop 15 times […]
Why buy one of those expensive and confusing universal remotes, clogged with enough buttons to launch a space shuttle, when you could accomplish the same electronic control right on your favorite mobile device? The Blumoo Universal Remote, now just $52.99 in the Boing Boing Store, harnesses the audio power of all your household equipment right […]
You may not love Microsoft Word, but you’ve definitely used it. Other than being one of the most ubiquitous programs on the planet, it’s been the go-to word processing system for more than a quarter-century because it’s as basic as it gets. But occasionally, you’ve got assignments that beg for a lot more options than simple […]
Almost everyone has their smartphone in a case of one kind or another. Beyond simple protection, finding a case that can charge your phone on its own, but doesn’t feel like it’s also adding a couple pounds to the phone’s weight is the tricky part. Billed as the world’s thinnest battery case, the ThinCharge iPhone […]