difference(){ 
union(){
    cube([5,35,1]);
    translate([2.5,0,0]) cylinder(h=1,r=2.5);
}
translate([11.5,35,0]) rotate([90,-45,0]) cylinder(r=10, h=50, $fn=3);
}

difference(){
union(){
    translate([-1,35,-1]) cube([7,35,3]);
    translate([2.5,70,-1]) cylinder(h=3,r=3.5);
}
translate([7.5,75,2]) rotate([90,-45,0]) cylinder(r=3, h=45, $fn=3);
translate([-2.5,75,2]) rotate([90,-15,0]) cylinder(r=3, h=45, $fn=3);
translate([6.5,75,-2]) rotate([90,45,0]) cylinder(r=3, h=45, $fn=3);
translate([-1.5,75,-2]) rotate([90,15,0]) cylinder(r=3, h=45, $fn=3);
}