$fn = 64;

/* --- PARAMETERS --- */
// Main dimensions
platform_diameter = 160;
base_diameter = 150;

// Thicknesses and heights
plate_thickness = 4;
base_thickness = 8;
internal_height = 15; // Height of the rotation mechanism

// Axle dimensions
axle_base_dia = 36;
axle_top_dia = 16;
clearance = 0.6; // Tolerance for smooth rotation

/* --- RENDER --- */
// Positioned side-by-side in optimal 3D printing orientation (no supports needed)
translate([0, platform_diameter/2 + 5, 0])
    turntable_platform();

translate([0, -base_diameter/2 - 5, 0])
    turntable_base();

/* --- MODULES --- */
module turntable_base() {
    // 1. Main Base Plate
    difference() {
        cylinder(d=base_diameter, h=base_thickness);
        
        // Hollow bottom to save material and prevent warping
        translate([0, 0, -1])
            cylinder(d=base_diameter - 20, h=base_thickness - 2);
            
        // Chamfer bottom edge (elephant foot compensation & aesthetics)
        translate([0, 0, -0.1])
            difference() {
                cylinder(d=base_diameter + 1, h=2.1);
                cylinder(d1=base_diameter - 4, d2=base_diameter + 1, h=2.1);
            }
    }

    // 2. Tapered Glide Ring (Low friction bearing surface)
    translate([0, 0, base_thickness])
        rotate_extrude()
            translate([(base_diameter - 12)/2, 0, 0])
                polygon([
                    [-1.5, 0],
                    [1.5, 0],
                    [0.5, internal_height],
                    [-0.5, internal_height]
                ]);

    // 3. Central Conical Axle (Self-centering pivot)
    translate([0, 0, base_thickness])
        cylinder(d1=axle_base_dia, d2=axle_top_dia, h=internal_height);
}

module turntable_platform() {
    // Calculate exact heights to ensure perfect assembly clearances
    boss_height = internal_height - 1; 
    skirt_height = internal_height + base_thickness - 2; 

    // Calculate conical hole diameters to maintain parallel clearance
    hole_d1 = axle_top_dia + clearance*2;
    hole_d2 = axle_top_dia + (axle_base_dia - axle_top_dia) * (boss_height / internal_height) + clearance*2;

    // 1. Main Top Plate (Prints upside down, flat on the bed)
    difference() {
        cylinder(d=platform_diameter, h=plate_thickness);
        
        // Chamfer the top edge (which is on the bottom during printing)
        translate([0, 0, -0.1])
            difference() {
                cylinder(d=platform_diameter + 1, h=2.1);
                cylinder(d1=platform_diameter - 4, d2=platform_diameter + 1, h=2.1);
            }
    }

    // 2. Outer Skirt (Hides the mechanism, prevents dust, provides grip edge)
    translate([0, 0, plate_thickness])
        difference() {
            cylinder(d=platform_diameter, h=skirt_height);
            translate([0, 0, -1])
                cylinder(d=platform_diameter - 6, h=skirt_height + 2);
        }

    // 3. Central Boss (Receives the axle)
    translate([0, 0, plate_thickness])
        difference() {
            // Boss outer body
            cylinder(d1=axle_top_dia + 16, d2=axle_base_dia + 16, h=boss_height);
            
            // Conical hole for axle (Expands upwards in print orientation, safe overhang)
            translate([0, 0, -0.1])
                cylinder(d1=hole_d1, d2=hole_d2, h=boss_height + 0.2);
        }
}