I recently attended the National Association of Rocketry's 60th annual competition, where I undertook a personal goal to determine if printed models could be competitive. The models in this competition are usually comprised of paper, balsa, plywood, fiberglass, and/or vacuformed plastic. Other than a few printed nosecones, and details used in scale models, printing has seldom been used.

This model is 100% printed in ABS. It achieved a second place altitude of 274 meters with an Estes 'C' motor, just six meters out of first place. As this was the first model rocket of any kind that I'd flown in over 30 years, I was mildly pleased with this result. (For an old guy, 'mildly pleased' = 'wildly ecstatic'.)

The intention of the Eggloft event is to fly a raw large egg to the highest possible altitude and return it unbroken. This model is intended for 18 mm model rocket motors, which should allow it to be flown in 'B', 'C', and 'D' motor class events.

Flying with a little more experience and a bit of fine-tuning of the model, I expect it can do better, and I expect that printed models will find a place in competition.

http://nar.org
http://nar.org/site/naram-60/
My other Things: https://www.thingiverse.com/garyacrowellsr/designs
My other Model Rocket Things:https://www.thingiverse.com/garyacrowellsr/collections/model-rockets-vcp
My Model Rocket Collection: https://www.thingiverse.com/garyacrowellsr/collections/model-rockets
My Collections: https://www.thingiverse.com/garyacrowellsr/collections