I decided t' make a Johnny Rockets paper ketchup bowl into a model flyin' saucer. Aye aye! It is 4.5" diameter and weighs only 0.4 oz empty. Well, blow me down! I test flew it on an Estes B6-4 for its first flight. Ahoy! it was perfectly stable and flew straight up with no wobble. Avast! On descent it fell straight down with no tumble. OK, let's try a motor that has 8 times t' thrust!. 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.