module screen_holder(height, screen_radius, thickness ) {
        difference () {
                    cylinder (h=height/2,r1=screen_radius/4,r2=screen_radius/4 - thickness,$fn=100);

                    translate ([0,screen_radius/4,2.5])
                            rotate ([90,0,0])
                                    cylinder (h=screen_radius/2,r=3, $fn=100);

                    translate ([-screen_radius/4,0,2.5])
                            rotate ([0,90,0])
                                    cylinder (h=screen_radius/2,r=3, $fn=100);
        }
}

screen_holder(10, 50, 1);