Spring Awakening - Three Stage Trap

 

While at Virginia Tech as the Instructor of Scenic Technology and Shop Supervisor, I was part of the technical design team.  The TD and ATD concentrated on the majority of the set.  I took on the task of designing and building the Three Stage Trap Mechanism.  The set design comprised of a rough cut lumber deck surrounded by a painted sky on the stage floor.  The show called for a trap to slide open (a few of the planks) for the grave scene, and the main trap to open as a door including a few of the planks.  After actors decend into the trap, the opening was to be filled with sky to match the stage floor, as if the opening to the underworld was sealed up.  

 

The sliding planks were solved by combining three planks together, and mortising in angle iron, which then slided through grooves cut into the sides of adjoining planks.  A hinged frame swung down to allow the hole to appear completely open, and swung back up to support the planks after they were slide back into place.  

A hydraulic cylindar was used to actuate the entire trap opening.  A gantry was built to support the piston, which pushed up on an arm welded to the trap frame.  The pivot of the trap was a one inch shaft supported by pillow blocks.  This was necessary to withstand the amount of force needed to raise the trap frame.  The force needed to open the trap frame was caculated to be about 500 lbs.  

A sunroof platform was then used to fill in the opening left by the trap frame being in it's open position.  Guides were CNC cut to ensure proper alignment and cam followers rode inside the guides.  A cable and a few pulleys actuated the sunroof.