use use render() difference() { ScrewThread(5, 5, 0.99, 55, 0, 0); $fn = 50; translate([0,0,-0.5]) cylinder(6, 1.9, 1.9); } color("red") x_measurement(3.8, [-1.99,0,2.5]); $fn=100; //#cylinder(5,2.5,2.5);