This is my scratch-built Black Brant II, designed for 18mm motors. I took measurements off my larger, out of production Estes Black Brant II (D-engine powered) to come up with this 73% downscale. I absolutely love how it turned out! Looking forward to flying it a whole bunch more, and hopefully with less breeze next time! Open Rocket file/plans available at www.RocketryForum.com Enjoy!