I created this effect after visiing Transworld in Chicago several years back.
I used an old Kitchenaid Mixer motor to turn a long length of pvc pipe fitted with eye bolt screws offset a few degrees along the shaft at each floorboard location. Dogear fence slats cut at the midpoint and pinned back together with a finish nail then anchored on one side with small hinges created the broken floorboards. Several of the same boards mounted together form a "door" at the end where a pneumatic cylinder opens that and pops up the monster.






I used an old Kitchenaid Mixer motor to turn a long length of pvc pipe fitted with eye bolt screws offset a few degrees along the shaft at each floorboard location. Dogear fence slats cut at the midpoint and pinned back together with a finish nail then anchored on one side with small hinges created the broken floorboards. Several of the same boards mounted together form a "door" at the end where a pneumatic cylinder opens that and pops up the monster.





