$fs=0.25;$fa=6;
union() {
difference(){cube([60,86,15],center=true);
translate([1.4,0,1.2])cube([54.8,83.6,15],center=true);
}translate([-28,-34.4,9])union() {
translate([0,17.2,0])difference(){union() {
cube([4,16.2,3],center=true);
translate([0,0,1.5])rotate([90,0,0])cylinder(h=16.2, r=2, center=true);
}
translate([0,0,1.5])rotate([90,0,0])cylinder(h=17.2, r=1, center=true);
}translate([0,51.6,0])difference(){union() {
cube([4,16.2,3],center=true);
translate([0,0,1.5])rotate([90,0,0])cylinder(h=16.2, r=2, center=true);
}
translate([0,0,1.5])rotate([90,0,0])cylinder(h=17.2, r=1, center=true);
}}
}