$fn = 64;

// Parameters
cup_height = 75;           // Overall height of the cup
bottom_diameter = 65;      // Outer diameter at the base
top_diameter = 70;         // Outer diameter at the top
wall_thickness = 2.5;      // Thickness of the cup walls
base_thickness = 3.0;      // Thickness of the solid bottom

// Calculated inner dimensions
inner_bottom = bottom_diameter - (wall_thickness * 2);
inner_top = top_diameter - (wall_thickness * 2);

difference() {
    // Outer shell
    cylinder(h=cup_height, d1=bottom_diameter, d2=top_diameter);
    
    // Inner hollow cutout
    // Translated up by base_thickness, and made slightly taller to ensure a clean top cut
    translate([0, 0, base_thickness])
        cylinder(h=cup_height, d1=inner_bottom, d2=inner_top);
}