// --- 1/2" PIPE RING TEST ARRAY ---
$fn = 80;
p12 = 21.3; // 1/2" Pipe OD
wall = 3.0;
h = 10;

offsets = [0.10, 0.15, 0.20, 0.25, 0.30, 0.35];

for (i = [0 : 5]) {
    translate([i * 35, 0, 0]) {
        difference() {
            cylinder(d = p12 + offsets[i] + (wall*2), h = h);
            translate([0,0,-1]) cylinder(d = p12 + offsets[i], h = h+2);
            
            // Identification Notches
            for (n = [0 : i]) {
                rotate([0, 0, n * 15]) 
                translate([(p12 + wall*2)/2, 0, h/2]) 
                cube([4, 1, h+1], center=true);
            }
        }
    }
}