$fn=64;

// Parameters
unit_height = 20;         // Height of a single unit in mm
units = 2;                // Number of units high
hex_outer_radius = 18;    // Outer radius of each hexagon
wall_thickness = 1.6;     // Thickness of the bin walls
floor_thickness = 1.6;    // Thickness of the bottom floor

// Calculated values
total_height = unit_height * units;

// Adjust inner radius so walls have uniform thickness
// r_inner = r_outer - (wall_thickness / cos(30))
hex_inner_radius = hex_outer_radius - (wall_thickness / 0.866025);

// Offsets for the surrounding hexagons
dx = 1.5 * hex_outer_radius;
dy = sqrt(3) * hex_outer_radius / 2;

// Center coordinates for the 7 hexagons
positions = [
    [0, 0],          // Center
    [0, 2*dy],       // Top
    [0, -2*dy],      // Bottom
    [dx, dy],        // Top Right
    [dx, -dy],       // Bottom Right
    [-dx, dy],       // Top Left
    [-dx, -dy]       // Bottom Left
];

// Module to generate the cluster shape
module hex_cluster(r, h) {
    for (pos = positions) {
        translate([pos[0], pos[1], 0])
            cylinder(r=r, h=h, $fn=6);
    }
}

// Main object
difference() {
    // Solid outer shell
    hex_cluster(hex_outer_radius, total_height);
    
    // Hollow inner cutouts
    // Added +1 to height to prevent Z-fighting at the top edge
    translate([0, 0, floor_thickness])
        hex_cluster(hex_inner_radius, total_height + 1);
}