use use $fn = 48; r = 100; module mobius_twins() { a_step = 20; half_a_step = 10; sr = 0.14 * r; half_r = r / 2; module mobius() { difference() { rotate(-a_step) ring_extrude( shape_liquid_splitting(5, half_r, 35), radius = r, twist = 180 ); union() { for(angle = [0: a_step: 360 - a_step]) { rotate([0, 0, angle]) translate([r, 0, 0]) sphere(sr); } } } } mobius(); rotate(90) mobius(); } mobius_twins();