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Mfr Part # ET16
BORESCOPE FOR ANDROID DEVICES
Klein Tools, Inc.
Crack a Safe's Combination with a Robotic Auto Dialer - Part 4
2
2023-06-29 | By Zach Hipps
License: See Original Project Test Equipment
I've been working on this safe cracking robot project for over 6 months, and there have been lots of ups and downs. But there's been a huge development that could potentially derail this whole project. I’m moving across the country, and this safe needs to stay here. One way or another, I have to open this safe in the next 5 days!
After seeing part 3 of this series, my friend Jonathan found a safe-cracking forum post showing how someone manually cracked this same model of safe. The forum post assumed that I had some basic knowledge of safe manipulation, so some of the terminology went over my head. But I understand the mechanics of safe locks well enough that I got the broad strokes. The first thing the forum post suggested I use was a dial indicator. This is a machinist tool that measures very small distances and dimensions. I happened to have one already, so I placed it up against the handle using a magnet. I can use the dial indicator to measure how far the handle moves as I’m trying a combination. The reason I need to be able to measure the handle movement has to do with false gates. The combination has 3 wheels that each have a deep slot. These are the three “true” gates that let the fence (deadbolt) slide into place and unlock the safe. Each wheel also has shallow slots called “false” gates. These false gates let the fence start to slide into place, but not enough to open the safe. If I try to open the handle on a combination that has one or more gates (whether they’re true or false) the dial indicator will show more movement compared to a combination without any gates. I cycled through and found all the gates for all three wheels. And better yet, I had a page full of measurements showing which numbers allowed the handle to move the furthest. These were the most promising numbers and gave me a couple of combinations to try. Unfortunately, I didn’t have any luck.
At this point in the project, I’m running out of time and things to try. I need to start packing up my office for my move, so I invited my brother-in-law (the owner of the safe) Levy over to discuss some options. He was ready to take an angle grinder to the back of the safe to get inside, but I still had one more trick up my sleeve. I found a small borescope camera that can be used to see inside small openings. Levy gave me the go-ahead to drill a ¼” hole into the front face of the safe near the combination dial. If I could drill a hole in the right spot and push the camera through, I would be able to see all three wheels and the fence deadbolt. My plan was to try to align the wheels visually using the small camera. As I drilled, a lot of fine dust was coming out of the hole, which is the refractory cement used for fireproofing the safe. I was able to get through the metal door and refractory cement with relative ease. Now it was time to push the camera through. I was able to push through the hole I’d drilled, but I soon hit the inner felt backing material of the safe. I needed to find a way to bend the camera at a 90-degree angle so I could see the wheel pack. Fortunately, I was able to achieve that bend by putting more force on the camera cable as it pushed against the felt backing. It slid free and made the bend, revealing (to our shock and excitement!) the wheel pack!
At this point, Levy and I were feeling absolutely pumped! We started cheering and giving each other high fives and hugs. However, we weren’t done. We were so full of adrenaline we took a few breaths to calm ourselves down. This next part would take steady hands, so we couldn’t let all the excitement jeopardize the mission when we were so close to our goal. I carefully moved the camera into position and soon found a large piece of sheet metal that looked suspiciously like the fence that slides into the gates. We let out another cheer when I confirmed this suspicion by jiggling the handle back and forth! Now I needed to find a way to hold the camera cable in place to steady our view. Levy suggested masking tape, but I had some poster putty close by that solved the problem even better. I wrapped the putty around the cable and fastened it to the opening I had drilled. This stabilized the camera and gave us a perfect view of the fence and wheel pack! My heart was pounding at this point. I had worked for months on opening this safe, and I was just moments away from victory! I slowly moved the first wheel into place passing several false gates. The true gate was easily identifiable because it was 10x deeper than the false gates. I started to move the dial for the second number, but my heart skipped a beat when I realized I had turned the dial the wrong way! This shifted the first wheel slightly. After a moment of inspection, I was confident that it would still be close enough to not interfere with the fence sliding into place. I continued turning the dial to reach the second true gate. This was it; I was in the home stretch! I turned the dial to its final position, and I could see all three true gates were aligned and the handle turned completely and fell into place! Success! Levy and I let out a series of yells and cheers, and because it was late at night, probably woke the whole neighborhood! At last, we had opened his safe!
I gave Levy the chance to clear out his things before we started disassembling the inner felt backing. Removing this large flat material revealed the inner workings of the safe. We no longer needed the camera because we had a direct view of the wheel pack and the fence. We studied the wheels and confirmed (several times) we had the correct combination before closing the safe and trying again. I wanted to know why my auto-dialing robot was unable to open the safe, and it turns out that I had dialed the right combination, but my handle servo wasn’t strong enough to turn the handle far enough to trigger my limit switch. I tried making several adjustments but wasn’t successful. I partially blame the cheap construction quality of this particular safe. The handle was very hard to open and bound up very easily. I’m sure if I spent a little more time on this project, I could have gotten it to work, but I have run out of time because of my impending move. Maybe someday I’ll get my hands on another safe and refine my design so that I can open any safe that comes my way. In the meantime, I jokingly told Levy that if he ever has another safe that he needs open, do NOT call me!
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