You can use this to copy a cylinder lock key within minutes. Especially great if you have a key that says 'do not copy' on it. You will need:
Access to the key (for a few seconds)
A drinks can or other thin metal
Ruler or other hard blunt edge
I have copied a master key for an entire office block doing this and it worked fine.... I have also copied a Yale lock key for a lock which I have been having trouble picking.
Step 1: Copy the Key - Quick!
Get a copy of the key using either:
Scanner - easiest
Camera - you must have a scale present in the picture (ruler etc)
Impression in bluetak or clay, then scan it or photocopy it. I personally would try and highlight the impression with tipex or something first to ensure a good print.
Print 2 copies of it in the correct scale so that you have two 1:1 copies of the key
Now roughly cut the copies out. Don't worry about cutting each tooth properly, just leave excess paper around it all.
Step 2: Thin Metal
Take a drinks can/tin and cut a rectangle big enough to stick the key to, or any other thin metal. I have included picture of me copying the same key on a drinks can and a fish tin!
Stick 1 cutout key onto it.
Step 3: Cut the Copy
Cut the new metal key copy out. You need to cut it leaving some excess metal around the teeth area, we will need the excess later!
See the second picture if you are unsure what I mean....
Step 4: Make the Groove
Take another key with a groove in it, it doesn't have to be the original, we are going to use the groove in it to create our groove in the copy.
Now line the groove up with your printout and force a groove into your new copy using a ruler or something thin and blunt. Press the ruler down and whilst holding it down flatten the sides which will now be sticking up in a V shape. See the pictures for detail.
Step 5: Make the Final Cuts
Now that you have the correct grooves, you can line up the key with the second printed copy, at this point you will need to cut the second printout exactly around the profile of the key (teeth included). Now it will become apparent why we left some extra on the teeth; the groove will have shortened the height of the key and so the teeth now need to be cut higher up on the metal.
Cut the teeth with continual reference to the printout. This is the crucial part, it must be very accurate. Make sure the teeth are not slanting to one side, if this is the case then the thin metal may slide down the edge of the pins and not push them up. Use scissors with a good pointed cutting end and try to cut only using this end.... this allows you to get quite accurate cuts without manoeuvring the scissors around risking bending the teeth.
Step 6: Use the Key!
Insert the key into your lock of choice, do this slowly, you may need to wiggle it very gently, but if your copy is good then it WILL go in fine. Now you must use a tension wrench or otherwise to turn the lock because the metal is not strong enough. You may need to gently move the key in and out of the lock by a few millimeters. Its amazing when you see it turn!
The tension wrench is simply an L shaped flat piece of strong metal which can be inserted into the keyway allowing me to turn it. You can construct this from a paperclip, or use a thin flat screwdriver.
I have made four different keys using this method, and they all work!
If you find your copy isn't quite working, compare it to the printout again. If this looks fine, then watch the way the key interacts with the pins as it enters the lock... if you find it moves to the side of them, then bend the teeth in a bit to compensate.