Well after playing around I have made the popup ball. Now all I have to do is decorate it. Well maybe the wife can do that
Had fun trying different rubber bands but the number 16 ones worked the best after they where stretched a couple of times.
Also the sides the rubberband is connected to need to be reenforced with extra bassil so the side don't collapse.
Craig,
that is the problem I was having with my pop up ball, so I will reinforce with more paper, rather than sticks so that side does not collapse. I will post a picture when I'm done reinforcing