$fn = 64;

// --- Parameters ---
// Number of rings (2 rings = 1 center + 6 + 12 = 19 hexes total)
rings = 2; 

// Flat-to-flat inner dimension of each hex pocket (mm)
hex_size = 40; 

// Thickness of the walls between hex pockets (mm)
wall_thickness = 2; 

// Thickness of the solid bottom base layer (mm)
base_thickness = 2; 

// Height of the hexagonal walls (mm)
rim_height = 8; 

// Diameter of the mounting hole in the center of each hex (set to 0 to disable)
screw_hole_diameter = 4; 


// --- Calculated Values ---
total_height = base_thickness + rim_height;

// Center-to-center distance to maintain exact wall thickness
D = hex_size + wall_thickness; 

// Outer radius (center to corner) with a 0.05mm overlap to ensure a manifold 3D-printable mesh
R_outer = D / sqrt(3) + 0.05; 

// Inner radius (center to corner) for the pocket cutouts
R_inner = hex_size / sqrt(3); 


// --- Geometry ---
difference() {
    // Main baseplate body (union of overlapping outer hexes)
    union() {
        for (q = [-rings : rings]) {
            for (r = [max(-rings, -q - rings) : min(rings, -q + rings)]) {
                // Hexagonal grid basis vectors
                x = D * q + D/2 * r;
                y = D * sqrt(3)/2 * r;
                
                translate([x, y, 0])
                    rotate([0, 0, 30])
                    cylinder(r = R_outer, h = total_height, $fn=6);
            }
        }
    }
    
    // Pockets and screw holes to subtract
    for (q = [-rings : rings]) {
        for (r = [max(-rings, -q - rings) : min(rings, -q + rings)]) {
            x = D * q + D/2 * r;
            y = D * sqrt(3)/2 * r;
            
            translate([x, y, 0]) {
                // Hexagonal pocket cutout (shifted up by base_thickness, +1 for clean cut)
                translate([0, 0, base_thickness])
                    rotate([0, 0, 30])
                    cylinder(r = R_inner, h = rim_height + 1, $fn=6);
                
                // Center mounting hole
                if (screw_hole_diameter > 0) {
                    translate([0, 0, -1])
                        cylinder(d = screw_hole_diameter, h = base_thickness + 2);
                }
            }
        }
    }
}