Lego Duplo Helicopter By SteelLegJ in LivingLEGO & K'NEX6,01623Save PDFFavoriteIntroduction: Lego Duplo HelicopterBy SteelLegJFollowMore by the author: a simple helicopter for those who can't have the small lego's. Step 1: The Pictures The gray piece is a swivel to allow the rotars to spin freely