Help ... carousel with fixed positions ideas

Hy guys, i’m having a really big problem with a carousel, i started working with the base being a tutorial on gotoandlearn on “Creating 3D Carousels”. It works fine as a carousel but i need it to look always the same no matter how manny images i load … i need it exactly like this … this is my carousel with 15 images loaded, but if load 10 i get this or if i load 20 i get this … this where all done with a radius of 280 and the images in the back are not visible;.
I’ve tried calculating the radius by the number of images but it’s still not great looking
with 10 … with 15 an finally with 20

In the first example i calculate the speed like this speedValue = (360/numOf)/2, i need like that so i can allways center on 270 degrees … the pozitions like this
mc._y = centerY - mc._height/3;
mc._x = centerX + Math.cos((mc.angle) / 180 * Math.PI)*radiusX - mc._width/2;
end the scale like this mc._xscale=mc._yscale=360-mc.angle+10; or mc._xscale=mc._yscale=mc.angle-180 + 10; depending on the angle

In the second example i added this radiusX=numOf*22;


can anyone help with an idee some code whatever :D, and sorry for my bad english