overall_outer_diameter = 75;
overall_thickness = 15;

neopixel_holder_thickness = 7.5;
translucent_disk_thickness = overall_thickness - neopixel_holder_thickness;

ring_24_outer_diameter = 65.6 + 0.5;
ring_24_inner_diameter = 52.3 - 0.5;

ring_12_outer_diameter = 36.8 + 0.5;
ring_12_inner_diameter = 23.3 - 0.5;

ring_thickness = 6.7;
ring_z_offset = neopixel_holder_thickness - ring_thickness;

channel_length = overall_outer_diameter-3;

alignment_pin_position = (-overall_outer_diameter/2) + 1.5; 

$fn = 200;

module ring(h, od, id) {
    difference() {
        cylinder(h=h, d=od);
        cylinder(h=h, d=id);
    }
};

module channel() {    
    translate([-(channel_length/2), -2, ring_z_offset]) cube([channel_length, 4, ring_thickness+1]);
    translate([0, 0, -1]) cylinder(h=neopixel_holder_thickness+2, d=10);
};

module neopixel_holder() {
    
    difference () {
        
        cylinder(h=neopixel_holder_thickness, d=overall_outer_diameter);
        
        for (d=[[ring_24_outer_diameter, ring_24_inner_diameter], [ring_12_outer_diameter, ring_12_inner_diameter]])
            translate([0, 0, ring_z_offset])
                ring(h=ring_thickness+1, od=d[0], id=d[1]);
        
        channel();
    }
};

module translucent_disk() {
    cylinder(h=translucent_disk_thickness, d=overall_outer_diameter);
    for (x=[0, 1])
        mirror([x, 0, 0])
            translate([alignment_pin_position, -(4-0.2)/2, translucent_disk_thickness])
                cube([3, 4-0.2, neopixel_holder_thickness -ring_z_offset]);
};

translate([-(overall_outer_diameter/2+1), 0, 0]) neopixel_holder();
translate([(overall_outer_diameter/2+1), 0, 0]) translucent_disk();