Water Rocket Gridfins

I wanted to 3D print fins for a large water rocket but I couldn't find fins witha large enough wingspan without prohibiting mass penalties. So I decided to make fins that would be mass efficient but still drag inducing, and I arrived at these gridfins. These fins are made for BIG water rockets, the one I am building is about 12 liters.

You'll need to print the gridfin file four times for symmetry. Also, the ring may be slightly off size for your specific bottle. It is made to fit a 110mm 2L bottle. Be sure to try 'em out, and Happy rocketeering!