$fn=64;

// --- Parameters ---
tray_outer_diameter = 120;
tray_inner_diameter = 114;
tray_height = 18;
base_thickness = 2.5;

pot_ring_diameter = 60;
channel_count = 8;
channel_width = 4;
channel_height = 3;

module plant_stack_tray() {
    union() {
        // Main tray body with raised edges
        difference() {
            // Outer shell
            cylinder(d=tray_outer_diameter, h=tray_height);
            
            // Hollow inside for water collection
            translate([0, 0, base_thickness])
                cylinder(d=tray_inner_diameter, h=tray_height);
        }
        
        // Raised radial ridges (creates drainage channels between them)
        // Keeps the pot elevated above the collected water
        for(i = [0 : channel_count - 1]) {
            rotate([0, 0, i * (360 / channel_count)])
                translate([0, -channel_width/2, base_thickness - 0.1])
                    cube([(tray_inner_diameter/2) - 0.5, channel_width, channel_height + 0.1]);
        }
        
        // Central locating ring for small pot rings
        translate([0, 0, base_thickness - 0.1])
            difference() {
                cylinder(d=pot_ring_diameter + channel_width*2, h=channel_height + 0.1);
                translate([0, 0, -0.1])
                    cylinder(d=pot_ring_diameter, h=channel_height + 0.3);
            }
            
        // Center support pad
        translate([0, 0, base_thickness - 0.1])
            cylinder(d=pot_ring_diameter - 15, h=channel_height + 0.1);
    }
}

// Render the model
plant_stack_tray();