outside_radius = 21.4/2;
thickness = 1;
height = 5;

step_size = 1;

$fn = 100;

module ring(){
    linear_extrude(height)
        difference(){
            circle(outside_radius);
            circle(outside_radius-thickness);
        }
}

module myshape(){
    horizontal = 6;
    depth = 3;
    my_height = 5;
    rotate([-45,0,0])
        translate([0,0,-my_height/2])
            linear_extrude(my_height)
                polygon([[-horizontal, 0],[horizontal,0],[0,depth]]);
}

pattern_size = 1.75;
offs = 0.2;
cube_height = 20;
count = 4;
difference(){
    ring();
    for(step=[0:step_size:360]){
        h = cos(step*count) * pattern_size;
        rotate(step)
            translate(
                    [0,
                    outside_radius-thickness/2,
                    h+height-pattern_size+cube_height/2+offs])
                cube(size=[1,thickness+0.5,cube_height], center=true);
    }
}


// difference(){
//     ring();
//     steps = 4;
//     for(step=[0:steps]){
//         rotate(step*360/steps){
//             translate([0,8,5.5]){
//                 myshape();
//             }
//         }
//     }
// }

// translate([0,8,5.5])
//     myshape();