1

module example001()
{
        function r_from_dia(d) = d / 2;

        module rotcy(rot, r, h) {
                rotate(90, rot)
                        cylinder(r = r, h = h, center = true);
        }

        difference() {
                sphere(r = r_from_dia(size));
                rotcy([0, 0, 0], cy_r, cy_h);
                rotcy([1, 0, 0], cy_r, cy_h);
                rotcy([0, 1, 0], cy_r, cy_h);
        }

        size = 50;
        hole = 25;

        cy_r = r_from_dia(hole);
        cy_h = r_from_dia(size * 2.5);
}

example001();