- translate([width/2, 0, -1]) cylinder(r=height, h=height+2);
- translate([-width/2, 0, -1]) cylinder(r=height, h=height+2);
+ translate([width/2, 0, -1]) cylinder(r=thread_size, h=height+2);
+ translate([-width/2, 0, -1]) cylinder(r=1.5*thread_size, h=height+2);