union() {
	difference() {
		scale(v = [0.066, 0.066, 1]) {
			surface(file = "circle3.png");
		}
		translate(v = [0, 0, 4]) {
			cube(size = [500, 500, 1000]);
		}
		translate(v = [0, 0, -1]) {
			cube(size = [500, 500, 1]);
		}
	}
	translate(v = [16.5, 16.5, 0]) {
		cylinder(h = 1, r = 16);
	}
}