hollow cylinder 3d model

$fn = 120; // ====== PARAMETERS ====== outer_diameter = 40; inner_diameter = 33; height = 26; shaft_hole = 16; lip_thickness = 3.5; // ====== MODEL ====== difference() { // Outer body union() { // main cap cylinder(h = height, d = outer_diameter); // inner lip (for grip) cylinder(h = 8, d = inner_diameter + 0.5); } // Hollow inside translate([0,0,lip_thickness]) cylinder(h = height, d = inner_diameter); // Shaft hole (center) translate([0,0,-1]) cylinder(h = height+2, d = shaft_hole); }