include <BOSL2/std.scad>

$fn=100;

topHeight=140; // total height?
topWidth=26;

cutoutDepth=3;
cutoutHeight=8.3;
cutoutFromTop=17.75;

shelfHeight=30.5;
shelfDepth=13;

ballWidth=2*INCH;

thickness=145; //6*INCH;

rounding=2;

diff("remove","keep") {
  cuboid([topHeight-ballWidth,topWidth,thickness], anchor=BOTTOM, rounding=rounding){
    tag("remove") {
        // cutout
        position(BACK+BOTTOM+LEFT) down(1) right(cutoutFromTop)
            cuboid([cutoutHeight,cutoutDepth*2,thickness+4], anchor=BOTTOM+LEFT);
        // shelf
        position(FRONT+BOTTOM+LEFT) left(1) down(1)
            cuboid([shelfHeight+1,shelfDepth*2,thickness+4], anchor=BOTTOM+LEFT);
        // relief
        position(BACK+BOTTOM+RIGHT) left(shelfHeight) down(1)
            cyl(thickness+2,d=shelfHeight*3, anchor=FRONT+BOTTOM+LEFT);
    }
    tag("keep") position(FRONT+RIGHT) cuboid([ballWidth/2,topWidth/2,thickness], rounding=rounding, anchor=FRONT);
    // ruler
    //position(TOP+BACK+LEFT) up(10) back(15) ruler(topHeight,10);
  }
}
    
right(topHeight/2) fwd(topWidth/4) cyl(thickness, d=ballWidth, anchor=BOTTOM, rounding=rounding);