[lucb1e]

Seen a similar image a while back. Locks suddenly made a lot of sense then.

Perhaps make another one about how walker keys work with locks like these? If I remember correctly, they were keys with filed down teeth. You had to put the key all but one tooth into the lock and then nudge it all the way in while turning, which would knock the top half of the metal rods up, allowing the lock to open.

[gameshot911]

Same thing as a bump key? Basically you cut down all the notches to the lowest setting (ie the deepest cut for that model of key), and then exactly as you described you put the key in up to the penultimate notch, at which point you apply rotational pressure on the key and knock the key in with some force (aka "bump" it in). The force of the insert bumps all the pins up, and the torque applied to the key catches the top half of the pin in the "open" position as the mechanism falls. If you catch all the top halves, the lock is breached.