$fn = 64;

// --- Parameters ---
unit_height = 10;       // Base height of a single unit (mm)
height_units = 3;       // Multiplier for total height
hex_radius = 25;        // Outer radius of each hexagon (center to corner)
wall_thickness = 1.5;   // Thickness of the exterior walls
bottom_thickness = 2.0; // Thickness of the solid bottom floor

// --- Calculated Variables ---
total_height = unit_height * height_units;

// Distance between centers of adjacent touching hexagons (flat-to-flat)
center_dist = hex_radius * sqrt(3);

// Inner radius calculated to maintain exact wall thickness on the flat sides
inner_radius = hex_radius - (wall_thickness / cos(30));

// --- Modules ---
// Distributes geometry to the 7 hex cluster positions (1 center, 6 surrounding)
module cluster_positions() {
    // Center position
    children();
    // 6 surrounding positions
    for(i = [0:5]) {
        rotate([0, 0, i * 60])
        translate([center_dist, 0, 0])
        children();
    }
}

// Single hexagon properly oriented so flats face adjacent neighbors
module hex_prism(r, h) {
    rotate([0, 0, 30])
    cylinder(r=r, h=h, $fn=6);
}

// --- Main Geometry ---
difference() {
    // Main solid outer body
    cluster_positions()
        hex_prism(r=hex_radius, h=total_height);

    // Hollow out the bins
    translate([0, 0, bottom_thickness])
    cluster_positions()
        // +1 height ensures a clean manifold cut at the top surface
        hex_prism(r=inner_radius, h=total_height + 1); 
}