$fn = 64;

// --- Parameters ---
hex_flat_to_flat = 50;
hex_height = 6;

// Dovetail joint parameters
dovetail_w_in = 10;
dovetail_w_out = 16;
dovetail_length = 5;
tolerance = 0.3; // Clearance for easy interlocking

// Calculated point-to-point radius for the hexagon
hex_radius = hex_flat_to_flat / sqrt(3);

// --- Modules ---
module dovetail_male() {
    polygon([
        [-dovetail_w_in/2, 0],
        [ dovetail_w_in/2, 0],
        [ dovetail_w_out/2, dovetail_length],
        [-dovetail_w_out/2, dovetail_length]
    ]);
}

module dovetail_female() {
    // Slightly larger for tolerance, extending outwards to ensure a clean boolean cut
    polygon([
        [-(dovetail_w_in + tolerance)/2, 0.1],
        [ (dovetail_w_in + tolerance)/2, 0.1],
        [ (dovetail_w_out + tolerance)/2, -(dovetail_length + tolerance)],
        [-(dovetail_w_out + tolerance)/2, -(dovetail_length + tolerance)]
    ]);
}

// --- Main Geometry ---
difference() {
    union() {
        // Base Hexagon
        cylinder(r=hex_radius, h=hex_height, $fn=6);

        // Add male dovetails on alternating faces (0, 2, 4)
        for (i = [0, 2, 4]) {
            rotate([0, 0, i * 60 + 30])
            translate([0, hex_flat_to_flat/2 - 0.05, 0]) // Slight overlap for manifold union
            linear_extrude(height=hex_height)
            dovetail_male();
        }
    }

    // Subtract female dovetails on remaining faces (1, 3, 5)
    for (i = [1, 3, 5]) {
        rotate([0, 0, i * 60 + 30])
        translate([0, hex_flat_to_flat/2, -0.5])
        linear_extrude(height=hex_height + 1) // Extended height for clean cut through top/bottom
        dovetail_female();
    }
}