$fn=100; difference(){ union(){ cylinder(h=3, d=14); cylinder(h=7, d=9.9); } cylinder(h=8, d=8.1); } difference(){ cylinder(h=2, d=30); cylinder(h=2, d=26);} translate([30,0,0]) difference(){ union(){ cylinder(h=3, d=14); cylinder(h=7, d=9.9); } cylinder(h=8, d=8.1); }