The Orange Rush is a Quantum Tube rocket built using the Anti-Zipper construction discussed on Info Central.
In order to be on the safe side I made a few modification for strength. At the top of the fin can instead of just using a standard coupler which is about 7" long for a 4" airframe, I used a full-length phenolic coupler that runs the full length of the fin can. This makes the entire fin can double-walled and adds a lot of surface area for the fins to bond. I used chopped fiiberglass in my internal structural fillets and I foamed the fin can. There's a lot of weight added there, but it is strong.
Of course, I ditched the piston and added my own home-brewed coupler-based altimeter bay. In fact, the altimeter bay for this rocket is the same one I use for the Stretched Tethys. This rocket was also built with an Extended Kwik-Switch to accommodate longer motors.
The whole rocket weighs about 8 1/2 pounds without the motor, but I still get plenty of kick with J's and above and this is my primary EX rocket right now, although I need to come up with something else for winter flying -- Quantum Tube + freezing temps = couplers that don't fit and shattered tubes.
--Lance.
