Congratulations to graciepuppy, 7, whose design got the most votes in our Top Builder: Bottle Launcher Challenge! Here's what they have to say about it:
this is a marble cannon.(I made this with my dad's help)OK! (this is how it starts)first you put the marbles in the plastic bottle cannon.then the marbles will roll into a tiny hall-way and will roll out of the other door.then the marble will roll into the cardborad tunnel and then it will roll to the goal!