I created an instructable for Oblivion's drawbridge element since even I was having trouble following the pictures. I hope this helps you build Oblivion or just the element itself!

Step 1: Lower Framework

This step contains the ramp the ball waits on until the bridge allows it to roll.

Step 2: The Main Motor

This step contains the 1st motor and the mother switch that interacts with the pulley systems.

Step 3: Upper Framework

This step contains the spool that controls the bridge movement.

Step 4: Secondary Motor

This step contains the second motor that pulls the mother switch upwards to raise the bridge. It will then automatically turn off. This is a complex step so take your time.
IMPORTANT NOTICE!!!! - Te motor in this step is a slow-turning motor found in the knex amusement part series " Drop And Swing" set.
Other motors may bee too fast for the mechanism.