My brother Kevin has been asking me a lot of questions about rockets for the last couple of months and so when he came to visit a couple weekends ago I said "wanna build a rocket?" He said yes so I gave him two kits of his own. One was a beautiful Fliskits Deuce and the other was an Estes Venus probe I picked up on ebay for about $2. He was always asking about High Power stuff and I admit I really like high power, but I would rather fly my model rockets several times a week rather than a few high power flights a few times a year. So I showed him my real love of rockets and had him build his first scratch built rocket. He decided he wanted to do a cluster because it is cool! And he had never flown a cluster but we also wanted the option to fly on a single engine. Then he decided on 13mm and 18mm engines because he is cheap(read: in medical school). He got the great idea of a three finned rocket with a central 18mm and 3 13mm engines mounted on the ends or the middle of the fins. This was my first place to help-"keep your thrust as close to center as possible of your rocket will flop around like a fish" so we decided to mount the 13mm engines to the body tube and the fins to the 13mm engine mounts. Then I commented that it would be cool to make the central mount 24mm and use an adapter for the 18mm engines so when you wanted to you could really send the thing flying! So there we were, plan set.