These are obviously more streamlined than pop-bottle rockets and fly much higher. The rocket shown is a bit over 6 feet tall. I have not used an altimeter yet, so don’t know how high it goes, but it hits apogee at around 5 seconds from liftoff when filled 30% with water and with 100psi CO2. Fins are made from a corrugated plastic “for sale” sign and attached with PL Premium construction adhesive (Home Depot).
It uses a horizontal parachute deployment system (Youens). Rather than using a wooden trigger attached to launcher with a line, like my 6-liter rocket, this uses Youens airflap trigger idea. The airflap is made from a popcycle stick with a bit of curved FTC material wired/glued on to give it a little more surface area. The nylon hinge is wired to the rocket; the same wires also hold the tomy timer in place. The horizontal tube, which holds the chute, is made from a medicine container. Plastic Easter egg is on top. This rocket had 6 successful flights with chute deploying properly each time, and then deployment failed and it self-destructed upon re-entry. I think that I had wrapped the rubber band too tightly around the body and hence the extra force on the Tomy timer handle created more friction between the pin and popcycle stick than could be overcome – hence it never triggered to start the timer.