$fn=180; difference() { union() { cylinder(d=25, h=25, center=true); translate([0,0,5]) for(angle = [0, 180]) rotate([0, 0, angle]) translate([0,15,0]) rotate([90,0,0]) cylinder(d=15, h=15, center=true); translate([0,0,-5]) for(angle = [90, 270]) rotate([0, 0, angle]) translate([0,15,0]) rotate([90,0,0]) cylinder(d=15, h=15, center=true); } union() { cylinder(d=16, h=25.01, center=true); translate([0,0,5]) rotate([90,0,0]) cylinder(d=6.25, h=50.01, center=true); translate([0,0,-5]) rotate([0, 0, 90]) rotate([90,0,0]) cylinder(d=6.25, h=50.01, center=true); } }