This instructables will explain how to 3D Print a working key for your house or some padlocks. This is in case you want a spare key. I've seen other people have instructsable doing the same thing but trust me, this is much easier. In other ones you have to have skill and knowledge on 3D modelling, not much but enough to make it useless to people who have no interest or don't know how to model.
Please be careful as ABS or PLA aren't that strong and if you aren't careful may break inside your lock. All that is needed for this project is: The orginal key, 3D Printer, key decoder (3D Printed), small files.
Step 1: Make a Key Decoder
Go to http://www.thingiverse.com/thing:1091544
and 3D Print a key decoder unless you already have one.
Step 2: Decode the Key
Watch from 3:00 to 4:00
Place the first gap in the key closest to the handle inside the decoder and Slide it down until it stops at a number.Note down the number, then move onto the next gap on the key and dont stop until all 5 cuts in the key are recorded.
Step 3: Create the Key
Click on the customizer option above the download button. Type in the code that was decoded earlier in order. Look at the model, if it does not look like your original key then try reversing the keys number order. Then Create and download your key
Step 4: Print It Off
Obviously print your key that you have just made and try it out, don't stick it in the lock if its too tight, try filing or sanding the key until it fits the lock. If it does not work, in the customizer try reversing the number order of the key and check to make sure the key looks similar to the original.