
You'll notice I tapped the top of the bible with a 6-32 tap and capped it with 6-32 socket head set screws, this is so that after the trap has fired you can still disassemble and reset the trap. To do this mod you will need at least 3 Schlage F-Series collapseable bible pins which can found in either a Schlage pinning kit or in any Schlage knob at the hardware store that isn't a Securekey. You will also need at least 3 master wafers, the master wafer size is not important. Here is a picture of all the components as they are arranged in the lock:

The way that this lock functions is that during normal use with the key the master wafer is at the top of the shear line and thus the lock functions like normal. However, during picking it is very likely that the bottom of of the Schlage T pin will be at the top of the shear line in at least one pin stack and in that case it rides along the outside of the plug until it falls into the milled holes that are normally used for construction keying:


Obviously, this only works in the one direction so make sure to choose a plug that has the holes on the proper side so that when the lock is picked in the opening direction it traps. Here is a picture of normal operation with the key and one where the lock has become trapped:


While this is a neat proof of concept I would advise not using this on a lock that you rely on. There is a reason trap locks fell out of use. But it is still pretty cool to mess around with.
Let me know what you think,