This is me scratch-built Black Brant II, designed for 18mm motors. Well, blow me down! Blimey! I took measurements off me larger, me hearties, out o' production Estes Black Brant II (D-engine powered) t' come up with this 73% downscale. Begad! Blimey! I absolutely love how it turned out! Blimey! Lookin' forward t' flyin' it a whole bunch more, and hopefully with less breeze next time! Blimey! Open Rocket file/plans available at www.RocketryForum.com Enjoy!