// Parametric 3x 120mm Fan Wall Pressure Shroud (Left Half)
// For 6U Open-Source Storage Array
// Standard Units: Millimeters (mm)

$fn = 64;

shroud_w = 198.0; // Half-width (split down center)
shroud_h = 220.0;
shroud_depth = 25.0;
wall_t = 3.5;
fillet_r = 5.0;

// Standard 120mm Fan dimensions
fan_bore_d = 118.0;
fan_hole_spacing = 105.0;
insert_m4_d = 5.6;
insert_m4_h = 6.5;

module fan_aperture_with_fillet() {
    // Main Bore with 5mm Intake Radiused Fillet
    cylinder(d=fan_bore_d, h=shroud_depth + 2);
    
    // Front Radiused Inlet (Cone approximation / Torus cutout)
    translate([0, 0, -0.1])
        cylinder(d1=fan_bore_d + 2*fillet_r, d2=fan_bore_d, h=fillet_r);
        
    // 4x Fan Mounting Holes (105mm square pitch)
    for (dx = [-fan_hole_spacing/2, fan_hole_spacing/2]) {
        for (dy = [-fan_hole_spacing/2, fan_hole_spacing/2]) {
            translate([dx, dy, -1]) {
                cylinder(d=4.5, h=shroud_depth + 2);
                // Rear M4 Heat-Set Brass Insert Pocket
                translate([0, 0, shroud_depth - insert_m4_h + 1])
                    cylinder(d=insert_m4_d, h=insert_m4_h + 1);
            }
        }
    }
}

module fan_wall_left() {
    difference() {
        // Main Solid Shroud Block
        cube([shroud_w, shroud_h, shroud_depth]);
        
        // Fan 0 Aperture (Left: X=66.0, Y=110.0)
        translate([66.0, 110.0, 0])
            fan_aperture_with_fillet();
            
        // Fan 1 Aperture (Center-Split: X=198.0, Y=110.0)
        translate([198.0, 110.0, 0])
            fan_aperture_with_fillet();
            
        // MCIO Twinaxial Cable Pass-Through Slot (Lower Left)
        translate([15.0, 15.0, -1])
            cube([45.0, 15.0, shroud_depth + 2]);
            
        // Perimeter Extrusion Mounting Holes (Ø4.5mm with countersink)
        // Top Edge
        translate([20.0, shroud_h - 10.0, -1]) cylinder(d=4.5, h=shroud_depth + 2);
        translate([100.0, shroud_h - 10.0, -1]) cylinder(d=4.5, h=shroud_depth + 2);
        translate([180.0, shroud_h - 10.0, -1]) cylinder(d=4.5, h=shroud_depth + 2);
        // Bottom Edge
        translate([20.0, 10.0, -1]) cylinder(d=4.5, h=shroud_depth + 2);
        translate([100.0, 10.0, -1]) cylinder(d=4.5, h=shroud_depth + 2);
        translate([180.0, 10.0, -1]) cylinder(d=4.5, h=shroud_depth + 2);
        // Left Frame Flange
        translate([10.0, 60.0, -1]) cylinder(d=4.5, h=shroud_depth + 2);
        translate([10.0, 160.0, -1]) cylinder(d=4.5, h=shroud_depth + 2);
        
        // Center Split Interlocking Lap Joint / Dovetail (Right Edge)
        translate([shroud_w - 5.0, 0, -1])
            cube([6.0, shroud_h/2, shroud_depth/2 + 1]);
        translate([shroud_w - 5.0, shroud_h/2, shroud_depth/2])
            cube([6.0, shroud_h/2 + 1, shroud_depth/2 + 1]);
    }
}

fan_wall_left();