Keys cost like what, $2 to copy at a locksmith? But where’s the fun in that? Here’s an easy way to cut your own keys using a CNC mill!
[Bolsterman] now “works” for a real estate company that rents out various properties. Whenever someone moves out, the locks need to be changed ASAP. They use Schlage locks, which can be re-keyed to any pin combination. New keys are typically cut with a punch or a key cutting machine — he actually had one years ago, but got rid of it. Not wanting to buy a new one for his new job at the real estate company, he decided to see how hard it would be to turn his small desktop CNC into his own personal key cutting machine.
All it took for [Bolsterman] to turn his mill into a key cutting machine was a 3/8th 90° countersink bit with the end ground to a flat approximately 0.055″ across (0.035″ is the width of a factory key, but a bit of leeway makes it easier to make the key). Then you simply zero the mill off of the shoulder of the key, and using the handy Schlage pin chart (included in the original link), cut the grooves!
To automate all of this, [Torrie Fischer] created a python script for generating the GCode for keys based on [Bolsterman's] technique — it’s hosted over at Noisebridge’s Wiki – check it out!
But if all that seems like too much effort, you could just print a new key instead…