faytree - I don't think so. And you left out the letter "i".
I think the marble race kids have their own special name for BFDI, but they always use the abbreviation. They never use the actual words for some reason.
tone121 - You should SEARCH for answers before asking questions. That's the difference between a "noob" and someone who knows how to find things. Now, just to be nice, I did the search for you, and found THIS
It's NOT symmetrical. Take a look at the center line. The whole structure is shifted to the right by 0.5 meters, which is stretching the springs on the right side of center, and compressing the springs on the left side of center. So, when the circles on top fall down, they tend to roll to the left because of the offset spring tension. Does that make sense?
Maybe you are not pressing the correct Enter key. Full size keyboards that include a numeric keypad have two Enter keys (One may be labeled "Return" on some keyboards). On my keyboard, one Enter key is just above the right side Shift key on the main alphabetic portion of the keyboard, and the other Enter key is on the far right side, and is part of the numeric keypad. It's the Enter key that is part of the main alphabetic portion of the keyboard that will work with this scene. Except for that, I cannot help you any further.
Why do you mention "Free to use"? ALL scenes are free to use because we do not allow buying or selling on Algobox. You did mention that you want credit if someone uses your scene, and that's Okay to do.
I can still remember when I was 10, and that was a VERY long time ago! If I wanted something badly enough, I would work and earn some money to pay for it. But if the item I wanted was expensive, then I would pester my mom and dad for the money. Sometimes they would buy it for me if I promise to do extra chores around the house. Then when I had kids of my own, they did the same thing to me!
You may THINK they are perfectly in line but just as in real life, any microscopic jitter or noise will throw them off-balance. Algodoo does a pretty good job of emulating real-life physics, and that's why the balls fall.