use <library.scad>
a = 10.16;
d = 1.6;
thickness = 2;
translate([0,a,0]){hole(a,d,thickness);}
translate([0,-a,0]){hole(a,d,thickness);}
for(i=[0:5]){
translate([a*i,0,0]){hole(a,d,thickness);}
}
module hole(a,d,thickness){
difference(){
translate([0,0,thickness/2]){cube([a,a,thickness],center=true);}
translate([0,0,thickness/2]){cylinder(h=thickness*2,r=d,$fn=100,center=true);}
}
}