How do you beat tube on fantastic contraption

first you build 2 contraptions that fall a short ways and get stuck onto each other, butmake surethat they are ramped at least 45 degrees. Then make a catepillar like thing that is on top of a third so as to make one side more angled, then the catepillar will climb up. Or you just make a catapult that flings the ball up. Either way is fine