$fn=60;

include <BOSL2/std.scad>

base_width=30;
base_height=10;
base_length=100;

difference() {
    union() {
        cuboid([base_width,base_length,base_height], rounding=1);
       top_half() xcyl(d=base_length, l=base_width, rounding=1);
    }
    top_half(z=base_height/2) xcyl(d=base_length*3/4, l=base_width, rounding=-1);
    top_half(z=base_height/2) xcyl(d=base_length, l=base_width/3, rounding=-1);
    translate([0,base_length/3,0]) zcyl(d=5, l=base_height, rounding=-1);
    translate([0,-base_length/3,0]) zcyl(d=5, l=base_height, rounding=-2);
}
difference() {
    top_half(z=base_height/3) xcyl(d=base_length/2, l=base_width, rounding=1);
    top_half(z=base_height/2) xcyl(d=base_length/2, l=base_width/3, rounding=-1);
    translate([0,0,base_height]) xcyl(d=5, l=base_width, rounding=-1);
}