untested. inspired by this http://www.instructables.com/id/Soda-Bottle-Rocket./ I thought it would be fun to see if more thrust could be obtained by creating a venturi nozzle. Nozzle should spin onto bottle like a cap.follow basic instructions in link above. launcher should epoxy into 1 inch pvc or abs. launch trigger is with 1/8 wire (coathanger will work). It may need a bead of silicone in the bottom of the launcher to create a good seal.