I used a 3" diameter cardboard tube from a large format printer paper reel to make a rocket. There are five STL files attached that are needed to make this rocket in addition to a cardboard tube. The parts are press fit together but also get glued to stay in place. I used a regular little tube of Krazy glue for assembly. 

STL Files

Bottom Fin

(4)-Bottom Fins needed/Rocket

Connected the “Bottom Body” using the “Fin Pins” and Glue

Nose Cone

(1)-Needed/Rocket

Goes on top and probably needs supports for printing. See picture. 

Bottom Body

(1)-Needed/Rocket

Has holes to accept the (3)-Nozzles on the bottom and 8 holes to accept “Fin Pins” to attach the 4 fins.  May need supports on the bottom for the nozzle holes.

Fin Pins

(8)-Needed/Rocket

Press/Glue into fins and bottom body. May need brimming for better support, these are small. 

Nozzle

(3)-Needed/Rocket

Press/Glue into the bottom of body. May need supports to print.