May 15, 2015 | By Alec

Few things are as annoying as trying to open an old suitcase or combination lock and having forgotten the code. Did you do four zeros as usual? Your birthday? 1-2-3-4? Or did you mix it up a bit this time? Before you know it, you’ve tried a dozen different combinations without getting any results. Fortunately, 3D printing can even make this small part of our lives easier. For Hacker Samy Kamkar has developed a very cool 3D printed Arduino-based device that can crack any master combination lock in just 30 seconds. So there’s no need to get the bolt cutters. "Without doing any work, this can open the lock entirely automatically in 80 combinations," Kamkar explains. "If you do that one little test first, it can crack the lock in eight combinations or less."

The device he has built is called the Combo Breaker, and is a motorized, battery powered, 3D printed, Arduino-based combination lock cracking device that is very easy to use. And as Samy explains on his website, it is fairly easy to 3D print and build, portable and is even open source so everyone. Just imagine the havoc you could have caused at high school if you had one of these.

But of course the real question is: how do you guess a combination? For this, Samy has written up a very cool little program that enables everyone guess a combination by hand. As you can see in the clip above, the principle is simple. You need to start looking for three specific points of resistance by pulling up the shackle as hard as you can, which the software uses to greatly narrow down the number of possible combinations. In fact, it can be used to crack any combination lock in eight attempts or less. It’s such a simple procedure that you start wondering why these locks are used so frequently.

But if we’re going to pretend to be criminals (or open old locks we found laying around), you can now also do so in style using a handheld device for automatically cracking the code. This handy little tool does exactly the same as you could do by hand, but then uses a system of 3D printed pulleys and levers, and an Arduino featuring the cracking software. Using a small Pancake Stepper Motor and an Easy Driver, this is a fun and functional little 3D printing project that you can use to impress everyone.

Assembling and programming the parts is fairly straightforward if you’ve done it before, but closely watch Samy in the clip below to ensure things go smoothely. Really the only challenging part, for a change, is the 3D printing phase. For you first will have to get familiar with the lock and make sure the levers you 3D print will actually function on the lock you’re working with. Samy, at any rate, carefully measured the lock and dial before designing all parts, and you should too. Aside from that, it’s a fun and cool little project that really illustrates what you can achieve with a desktop 3D printer and a couple of electronics nowadays.

“I try to build things that are interesting to a general audience. And I hope getting this out there helps people make better decisions about the locks they use,” Kamkar says.

Interested? You can find a full list of all the necessary hardware on Samy’s website here, and all the necessary hacking software here on github


Posted in 3D Printing Applications


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