If what you said is true, that the balls are added inside each-other, then I think you have one panel inside another panel, inside another panel. I do not think this is what you want. I think you want to have to have all 3 inside the parent panel or frame or whatever, floating freely from each other.
Also you need to figure out what LayoutManager you are using and how that will effect things. You might want to figure out how to use LayoutManager null or something like that - as the layout manager will try and force your components into some sort of placement, whereas what you want to do is place them manually. I recommend you study this topic a bit, and try to manually place 1 ball before you try and place 3.