$fa=60
Difference(){
unión(){
cube ([30,150,5], center=true);
translate([0,75,0])unión(){
cube([30,5,15], center=true);
rotate([90,0,0]) translate([0,0,15])cylinder(h=5, d=30, center=true);
}
translate([0,-75,0])unión(){
cube([30,5,15], center=true);
rotate([90,0,0]) translate([0,0,15])cylinder(h=5, d=30, center=true);
}
}
translate([0,4,15])cylinder(h=75, d=3, center=true);
}