OpenSCAD parametric, 3d printable key (on a RepRap)

Nirav Patel's successful RepRap printed house key test!

Imagine that one day, you get locked out of our home, but instead of calling the locksmith, or furtively smashing your own window, you call up a friend and ask them to print you a new one.  Better still, you ask to borrow your neighbors printer, just for a 10 minute print.

Over at his blog, Nirav Patel has done some tests with his RepRap printer, and created a pair of OpenSCAD files that can parametrically be set to print any possible key combination of the two most popular US door key types (Kwikset KW1 and Schlage SC1).  Cleverly, he didn”t try this in his door lock first try – having no desire to try to pick plastic out of his front door if the thing snapped off – but tried some second hand tumblers instead.  He was successful!

Now, don’t get me wrong – part of me is now eyeing up the locks on my door with increased suspicion – however, our locks have been ‘hackable’ for decades.  Were it not for the ease and speed of plain old lock picking, it would be that metal blanks have been available for years – and easily filed down to match a mold of an existing key.  This is no great step forwards for burglers and thieves.

What it might be, however, is a glimpse into a future where instead of giving the spare key to your beau, you give them the 5 digit code and they print their own key.  Or a future where, as I mentioned above, you can create your own duplicate key wherever you can get access to a 3D printer.

I started writing that we might be best moving towards the two-factor authentication mode with regards to our house keys –  “something you have and something you know” security (like having a card, and knowing the PIN) but we’ve been using a two-factor system forever – we have the key, and we know the address.  This hasn’t changed.  Indeed, homes with security systems (and codes) double up that system.  I should make sure I don’t stash my address alongside my keys, hrm…

Lastly, and on a much lighter note – what fun it would be to integrate this into a treasure hunt!  The puzzles before it lead to a locked room (or box, or geocache), and subsequent maths challenges give the 5 digit code.  Print the key, and get the treasure within.  Fantastic 😀