What I did, was I put in a lunched lift as high as it would go, then made it go down all the way to the ground, etc....etc....etc....Really, I could have made it a 1/4 of its length because it got up to speed about 1/4 of the way through. But, I wanted to see how long I could make it. If I wanted to, I could have made it longer, but by the time I was done with it, I was bored. It took about a hour to make.