Summary

Simple tailfin to screw onto a soda bottle. Should give it some stability when flying through the air.

the rocket version has a hole through it, and a nozzle that you can use a shop air gun to fill it full of compressed air. A bit of water and it makes a fun rocket with a good launch tube.

latest bottle-tailfin-50mm_63mm-v1.1.stl I thickened the thread area to keep it from breaking when it's screwed tight onto the bottle.