Im always on the look out for functional things that 3d printers are really good at making.
model Rockets are one of those things especially because small changes in design affect there aerodynamics.

Here is a model rocket ( this one I made from scratch in blender )
Ive added some fun things here like variable twisting of the fins, and riffling to the rocket body.

Haven't launched it yet but it I have launched lots of model rockets and Im really looking forward to all the interesting design changes one can do when 3d printing model rockets.
I will probably wait until I have 5 or more ready to launch and ill be sure to set up some cameras so I can post the footage here

Here is a blend file ( try changing the angle in the deform modifier to affect how twisted the fins are)
manual-rocket-twist.blend.zip

and here are some pics
Screenshot-1.jpg


More pics of actual prints of this model rocket coming soon