	difference() {
		sphere($fn = 0, $fa = 12, $fs = 2, r = 10);
		%cylinder($fn = 0, $fa = 12, $fs = 2, h = 30, r1 = 6, r2 = 6, center = true);
	}
	%group() {
		cube(size = [25, 6, 3], center = true);
	}

