$fn = 64;

// --- PARAMETERS ---
roll_width = 210;         // Width of the paper roll (210mm = standard A4 width, adjust as needed)
roll_max_diameter = 120;  // Maximum diameter of the full paper roll
core_diameter = 20;       // Inner diameter of the cardboard core
wall_thickness = 5;       // Structural wall thickness

// --- DERIVED DIMENSIONS ---
base_w = roll_width + wall_thickness * 2;
base_h = roll_max_diameter / 2 + 40;
arm_ext = roll_max_diameter / 2 + 20;
spindle_r = core_diameter / 2 - 1;

// --- MAIN DISPENSER BODY ---
union() {
    // 1. Backplate
    cube([base_w, wall_thickness, base_h]);

    // 2. ArtArsenal / French Cleat Wall Mount (Back)
    // Top Cleat Spacer
    translate([0, -10, base_h - 20]) 
        cube([base_w, 10, 20]);
        
    // Top Cleat Wedge (downward angle for rail locking)
    hull() {
        translate([0, -10, base_h - 20 - 0.1]) cube([base_w, 10, 0.1]);
        translate([0, -0.1, base_h - 35]) cube([base_w, 0.1, 0.1]);
    }
    
    // Bottom Standoff / Plumb Bumper
    translate([0, -10, 0]) 
        cube([base_w, 10, 10]);

    // 3. Left Arm
    translate([0, wall_thickness, 0])
    difference() {
        hull() {
            cube([wall_thickness, 0.1, base_h]);
            translate([0, arm_ext, 0]) cube([wall_thickness, 0.1, 15]);
            translate([0, arm_ext - 15, base_h - 15])
                rotate([0, 90, 0]) cylinder(h=wall_thickness, r=15);
        }
        // Spindle drop-in slot (leaves 2mm outer wall)
        translate([2, arm_ext - 15, base_h - 15]) {
            rotate([0, 90, 0]) cylinder(h=wall_thickness, r=spindle_r+1);
            translate([0, -(spindle_r+1), 0]) cube([wall_thickness, (spindle_r+1)*2, 20]);
        }
    }

    // 4. Right Arm
    translate([base_w - wall_thickness, wall_thickness, 0])
    difference() {
        hull() {
            cube([wall_thickness, 0.1, base_h]);
            translate([0, arm_ext, 0]) cube([wall_thickness, 0.1, 15]);
            translate([0, arm_ext - 15, base_h - 15])
                rotate([0, 90, 0]) cylinder(h=wall_thickness, r=15);
        }
        // Spindle drop-in slot (leaves 2mm outer wall)
        translate([-1, arm_ext - 15, base_h - 15]) {
            rotate([0, 90, 0]) cylinder(h=wall_thickness - 1, r=spindle_r+1);
            translate([0, -(spindle_r+1), 0]) cube([wall_thickness - 1, (spindle_r+1)*2, 20]);
        }
    }

    // 5. Integrated Cutter Bar (Bottom Front)
    // Overlaps slightly with arms to ensure manifold geometry
    translate([wall_thickness - 0.1, arm_ext + wall_thickness - 10, 0])
    hull() {
        cube([roll_width + 0.2, 10, wall_thickness]);
        // Angled tear edge pointing up and forward
        translate([0, 9.5, wall_thickness]) cube([roll_width + 0.2, 0.5, 4]);
    }
}

// --- SPINDLE ---
// Printed vertically next to the main body for optimal strength
translate([base_w + 20, 20, 0])
union() {
    // Main shaft (sized to fit between the 2mm outer slot walls with play)
    cylinder(h=roll_width + 2, r=spindle_r);
    // Slight chamfer at the bottom for easier printing
    cylinder(h=1, r1=spindle_r - 1, r2=spindle_r);
}