I decided t' make a Johnny Rockets paper ketchup bowl into a model flyin' saucer. It is 4.5" diameter and weighs only 0.4 oz empty. I test flew it on an Estes B6-4 for its first flight. it be perfectly stable and flew straight up with no wobble. On descent it fell straight down with no tumble. OK, matey, let's try a motor that has 8 times t' thrust!. Blimey! An old (discontinued - too bad!) Aerotech E25-11 fit t' bill and here be t' video. This time it whipped off t' pad and flew straight up. On descent it tumbled because o' t' heavier motor.