difference(){
    cube([9,10,1]);
    translate([1,0,0]) cube([1,7,2]);
    translate([3,0,0]) cube([1,7,2]);
    translate([5,0,0]) cube([1,7,2]);
    translate([7,0,0]) cube([1,7,2]);
    translate([9,0,0]) cube([1,7,2]);
}

translate([6,10,0]) cylinder(h=1 ,r=3);
translate([3,10,0]) cylinder(h=1 ,r=3);
translate([3,10,0]) cube([3,30,1]);
translate([4.5,40,0]) cylinder(h=1,r=2);

translate([0.5,-0.2,0]) rotate([0,0,30]) cylinder(r=0.5, h=1, $fn=3);
translate([2.5,-0.2,0]) rotate([0,0,30]) cylinder(r=0.5, h=1, $fn=3);
translate([4.5,-0.2,0]) rotate([0,0,30]) cylinder(r=0.5, h=1, $fn=3);
translate([6.5,-0.2,0]) rotate([0,0,30]) cylinder(r=0.5, h=1, $fn=3);
translate([8.5,-0.2,0]) rotate([0,0,30]) cylinder(r=0.5, h=1, $fn=3);