$fn=100;

difference() {
    // https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Primitive_Solids#cylinder
    cylinder(h=15, r1=10, r2=0);

    // https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Primitive_Solids#cylinder
    translate([0, 0, 1]) cylinder(h=12, r1=8, r2=0);
    
    //cube(15);
}

translate([15, 0, .75]) sphere(.75);

translate([12, 0, .75]) sphere(.75);

translate([-15, 0, .75]) sphere(.75);

translate([-12, 0, .75]) sphere(.75);

translate([0, 15, .75]) sphere(.75);

translate([0, 12, .75]) sphere(.75);

translate([0, -15, .75]) sphere(.75);

translate([0, -12, .75]) sphere(.75);