mailbox_mount.js

const thickness = 3;
const side_height = 20;
const len = 210;
const wid = 155;
const pole_radius = 22;
const pole_height = 75;
const screw_hole_radius = 2.5;
const screw_hole_separation = 189;

function screwHole() {
    return rotate([0,90,0],
        cylinder({r: screw_hole_radius, h: thickness, center: [true, true, true] })
    );
}
function side() {
  return difference(
      cube({
        size: [thickness, len, side_height], 
        center: [true, true, false]
      }),
      screwHole().translate([0,screw_hole_separation/2,side_height/2]),
      screwHole().translate([0,screw_hole_separation/-2,side_height/2])
    );
}

function main () {
   return difference(
       union(
        cube({size: [wid, len, thickness], center: [true, true, false]}),
        cylinder({r: pole_radius+6, h: pole_height, center: [true, true, false] }),
        side().translate([wid/2,0,0]),
        side().translate([wid/-2,0,0])
       ),
       cylinder({r: pole_radius, h: pole_height, center: [true, true, false] }),
       rotate([0,90,0],cylinder({r: 1.5, h: pole_radius*2+12, center: [true,true,true] } ))
         .translate([0,0,pole_height/2]),
       cube({size: [100,50, 15], center: [true, true, false]})
         .translate([0,-65,0]),
       cube({size: [100,50, 15], center: [true, true, false]})
         .translate([0,65,0])
      );
}