$fn = 64;

// --- Parameters ---
rail_length = 600;         // Total length of the rail in mm
rail_diameter = 16;        // Diameter of the hanging rail
wall_clearance = 35;       // Distance from wall to center of rail
bracket_count = 5;         // Number of wall mounting brackets
bracket_width = 15;        // Width of each bracket
bracket_height = 50;       // Height of the wall plate
wall_plate_thickness = 6;  // Thickness of the wall plate
screw_hole_diameter = 4.5; // Diameter for mounting screws
screw_head_diameter = 9;   // Diameter for screw head countersink

// Derived parameter for arm height to ensure manifold geometry inside the cylinder
arm_height = rail_diameter * 0.6;

module wall_rail() {
    union() {
        // Main cylindrical rail
        translate([0, wall_clearance, 0])
        rotate([0, 90, 0])
        cylinder(h=rail_length, d=rail_diameter);

        // Wall mounting brackets
        step = (rail_length - bracket_width) / (bracket_count - 1);
        for (i = [0 : bracket_count - 1]) {
            translate([i * step + bracket_width/2, 0, 0])
            bracket();
        }
    }
}

module bracket() {
    difference() {
        union() {
            // Wall mounting plate
            translate([-bracket_width/2, 0, -bracket_height/2])
            cube([bracket_width, wall_plate_thickness, bracket_height]);

            // Tapered extension arm connecting plate to rail
            hull() {
                // Base at wall plate
                translate([-bracket_width/2, wall_plate_thickness - 0.1, -9])
                cube([bracket_width, 0.1, 18]);
                
                // End at rail (penetrates slightly past center for manifold union)
                translate([-bracket_width/2, wall_clearance, -arm_height/2])
                cube([bracket_width, 2, arm_height]);
            }
        }

        // Top screw hole
        translate([0, 0, 16])
        screw_hole();

        // Bottom screw hole
        translate([0, 0, -16])
        screw_hole();
    }
}

module screw_hole() {
    // Screw shaft hole
    translate([0, -1, 0])
    rotate([-90, 0, 0])
    cylinder(h=wall_plate_thickness + 2, d=screw_hole_diameter);
    
    // Screw head countersink
    translate([0, wall_plate_thickness - 2.5, 0])
    rotate([-90, 0, 0])
    cylinder(h=2.51, d1=screw_hole_diameter, d2=screw_head_diameter);
}

// Generate the object
wall_rail();