3D Printed Key Saves The Day

When [Odin917’s] parents went away on vacation, they took the apartment mailbox key with them. With the mail quickly piling up in the mailbox, he needed to get in there. He could have had the building super replace the lock, for a fee of course. Instead he had his parents email a photo of the key, which he used to 3D print his own copy.

Using a photograph as a template for a 3D printed copy is nothing new. We’ve covered it in-depth right here. However, this is the first time we’ve seen the technique put to use for good – in this case avoiding a hefty lock replacement fee.

He did his modeling in Autodesk’s free Fusion 360 CAD software. He then printed it out, and the box didn’t open. It took three revisions before the perfect key popped out of the printer. This particular mailbox uses a 4 pin tumbler, which makes it a bit less forgiving than other mailbox locks we’ve seen.

Admittedly this isn’t [Odin917’s] first time working with locks. Back in 2013, he submitted a parametric bump key model to Thingiverse.

Picking locks isn’t just for getting the mail. Locksport is a popular pastime for hardware hackers.

53 thoughts on “3D Printed Key Saves The Day

        1. Incredibly, there are some people in the world who are users of 3D printers who don’t also know how to pick locks.
          It also might be technically legal but it’s probably a great way to get yourself in trouble.

          1. If all you want to do is open the lock to retrieve your mail, the monumentally quicker way would be to just pick it. Or learn how to pick it, then pick it. Taking photos of keys, making the design files, 3d printing several iterations of keys is akin to building an airplane just to fly 5 miles when you could walk or take a car or hire someone or take a bike.

            Of course it works and if you only have those tools available or are curious about if it is possible then go for it. Just be aware that this method is incredibly convoluted and time consuming compared with the alternative is the only real point being made here.

            Perhaps if one insisted on using 3D printing, this process could be made easier or quicker (start to finish) if somebody made some software to automatically turn a photo of a key into a 3D printed key? I would mostly worry about the strength of the key, depending on the material used to print with.

          2. “It also might be technically legal but it’s probably a great way to get yourself in trouble.”
            If it’s your own lock, you aren’t in trouble. You might look suspicious, but you might also look suspicious wiggling around a plastic key in the lock.

          3. @dmalhar

            In the US at least, the mailbox is federal property that is only on loan to you (or the property) so there might be some technicality that could cause you trouble. You’re not vandalizing it so you shouldn’t get in trouble.

          4. I’m pretty sure it’s like “conspiracy to commit larceny” or something, a felony offense to even posses a pick set in VA without a professional locksmith license/certification. Needless to say the lock sport community in VA is lacking.

  1. That’s pretty cool. I’d be a bit concerned to try it though… what if the printed key broke off in the lock. That might be a bigger fee and an uncomfortable conversation with the landlords!

    1. On multi tenant mailboxes, the postman has a key to open the entire face with the doors attached. Only the tenants tend to have actual individual keys. Since I know the postman pretty well, he usually would give me my stuff if he had it open, but typically they are not supposed to provide the mail even in the event you lost your key.

    1. even with poor tools and skills you can pick a 4 pin tumbler in a matter of minutes. not to mention it’s probably all worn out. I taught myself how to pick with some homemade tools and a 4 pin bike lock

          1. @Steve
            Most places make it illegal for you to carry them around. Simply having one on private property (it is your building you have a legal right to access after all) is not enough to get you in trouble.

  2. I had a similar problem with a Honda motorcycle. I was new to riding, bought this bike secondhand and it only had one key. I noticed the key had a number stamped on it, took a photo of it assuming I’d just need that number and the VIN to get a replacement if I ever lost the key.

    Well sure enough, I lost the only key. Called the dealer nearby and casually asked for the key, found out it wasn’t that simple. That their only option was to sell a new ignition, fork lock and fuel tank (after finding someone crazy enough to drill out a lock in a gas tank). That was not a cheap solution, would have cost me more than the bike did.

    While I was looking at the photo of the useless number stamped on the key and being regaled with the horrid details of what this was going to cost me. I thought “I bet I can make a key from this photo”

    Ordered the 4 possible blanks for that year of motorcycle. Traced the key out in illustrator, scaled it to 1:1, cut it out with a hobby knife and glued it to the key. Got to work with rat files and was able to duplicate it! Didn’t work first try, but with nothing to lose but time and a lot of money, kept at it and got a working key.

    Learned my lesson and got a handful of duplicates made after that adventure.

  3. Think about this a somebody gets a pic of your house key and sends a picture it gets printed now voila they are in your house. I see the good in this but the bad can be really bad if this is in the wrong hands.

    1. This is a service out there already, key.me , you email in pics of your keys and they will send you copies through the mail or you can pic it up at a kiosk. they keep the picture on file in case you need another key later.

    2. That’s already a thing… People posting keys to their new bought home on social media. If you have the standard locksmith cutting tools you can create the key.
      Breakins and thefts happen that way. Good luck proving to the insurance companies that your stuff was stolen since there will be no signs of breaking and entering.

        1. Hehe I don’t know, but it’s good to be aware of these things. Just like people who post pictures of their barcoded festival tickets, and then can’t get in because someone else used the ticket already.

    1. The lock in my car didn’t work, battery was discharged and recently I’ve fixed lock which didn’t want to close, so car was trully closed. Locksmith managed to bend upper part of doors a little, insert u-shaped bar and just pulled a handle from inside.

      1. Between high school and college I worked for the summer at a Ford dealership as a service porter. Usually I would be given a number, go back to the service lot, find the car with that number on it’s tag and bring it up for the customer. One day I was sent to get a customer’s blue Escort. For whatever reason the service manager didn’t have the number. I found a blue Escort. The keys fit. I brought it to the front.

        1/2 hour later I had the service manager yelling at me that the customer was in a hurry and still waiting for their car. About that time one of the mechanics showed up yelling at me that I took the car he was supposed to be working on. WTF!

        I pointed out the car which I had brought up. The service manager quickly pulled me to the side, away from the customer. It turned out there were two blue Escorts and the same key fit both! I was told to just go with it because they didn’t want the customer knowing how insecure the keys were.

        I was not very impressed.

        1. I’ve wondered about this in the past, specifically regarding NYC apartments. There are something like 1.2million residential apartments in NYC. If half of them have standard Kwikset keys for their lock (5 pins, 8 options per pin = 32768 combinations), then every Kwikset key opens something like 18 doors in the city, and that’s without eliminating any undesirable key combinations (e.g. 1-1-1-1-1).

      1. You think his parents have PGP installed in their -no-doubt- gmail account? (and a key prepared.) Does Gmail even support it? Or do you have to pre-encrypt? But isn’t that against Google’s spy-EULA?
        I think a better way would be to go for an encrypted RAR, that’s more universally present and ‘a thing’ and it has encryption. But even there, do your parent have winrar or similar installed? I’m not sure how big it is with the non-tech crowd. I know some non-tech people that do have winrar though, although I’m not sure they know you can encrypt archives.

        Anyway I was merely pointing out how if you order stuff for instance they send all info and confirmation andsoforth in plaintext, I don’t know of any business that uses any encryption of any kind for E-mail.
        Sometimes they even ‘confirm’ rather sensitive info including credit-card info and personal ID information, which hops through several inbetweens, and often through several countries.
        I’ve had to reject some companies based on their excessive flow of personal info over E-mail, while their product was satisfactory, but when they go insane in that area it’s just too much.

        Incidentally, I understand that even Wikileaks was mailing Trump Jr without any encryption (since the investigators and newspapers could get the the E-mails and read them it seems).

  4. Where I live mail locks are lever locks. Difficult, perhaps harder than a disc lock to pick and would certainly require a highly specialized tool.
    No bogota rakes or jigglers for those.
    I believe US military weapons padlocks are Sargent & Greenleaf lever locks.

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