I decided to make a Johnny Rockets paper ketchup bowl into a model flying 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 was perfectly stable and flew straight up with no wobble. On descent it fell straight down with no tumble. OK, let's try a motor that has 8 times the thrust!. An old (discontinued - too bad!) Aerotech E25-11 fit the bill and here is the video. This time it whipped off the pad and flew straight up. On descent it tumbled because of the heavier motor.