length=75;
width=36;
thickness=6;
overlap=0.1;

difference() {
    cube([length,width,thickness]);
    
    // cable tie cutout
    cable_tie_width=5;
    translate([length/2-cable_tie_width/2+6.5,-overlap/2,-overlap]) {
        cube([cable_tie_width,width+overlap,3+overlap]);
        cube([cable_tie_width,3,thickness+2*overlap]);
        translate([0,width-3+overlap,0]) {
            cube([cable_tie_width,3+overlap,thickness+2*overlap]);
        }
    }
    
    // screw holes
    screw_hole_radius=1.25;
    translate([25.5,width/2,-overlap/2]) {
        cylinder(thickness+overlap,screw_hole_radius,screw_hole_radius);
        translate([0,0,thickness-2]) {
            cylinder(3+overlap,screw_hole_radius+1,screw_hole_radius+1);
        }
        translate([24,0,0]) {
            cylinder(thickness+overlap,screw_hole_radius,screw_hole_radius);
            translate([0,0,thickness-2]) {
                cylinder(3+overlap,screw_hole_radius+1,screw_hole_radius+1);
            }
        }
    }
    
    // battery charger inset
    charger_width=13;
    charger_length=25;
    charger_height=2;
    translate([15.5,2,thickness-charger_height+overlap]) {
        //cube([charger_length,charger_width,charger_height]);
    }
}

// battery inlay/walls
wall_width=15;
radius=16.5;
translate([0,0,thickness/2+1.5]) {
     difference() {
         union() {
             cube([wall_width,width,radius]);
             translate([length-wall_width,0,0]) {
                 cube([wall_width,width,radius]);
             }
         }

         rotate([0,90,0]) {
             translate([-radius-thickness/2,width/2,2]) {
                 #cylinder(length-4,radius,radius);
             }
         }
    }
}

$fn=70;