// Easyroll Wheel bearing seal parameters
$fn = 120;
// High resolution

outer_diameter = 40; //
hole_diameter = 12.7; //
base_thickness = 1.5; // [cite: 9]
total_height = 10; // Main body height [cite: 10]
lip_thickness = 1.5; // [cite: 10]

// Extension Dimensions
bottom_ext_h = 4; // 4mm height [cite: 14]
bottom_ext_w = 3; // 3mm width [cite: 14]
top_ext_h = 5.5; // 5.5mm height [cite: 14]
top_ext_w = 23.3; // 23.3mm width [cite: 14]

// Interior Ring Dimensions
int_ring_h = 1.2; // 1.2mm high
int_ring_od = 20.2; // 20.2mm Outer Diameter
int_ring_id = 18; // 18mm Inner Diameter (leaves a gap for bearing between interior ring and 12.7mm hole)

union() {
difference() {
// 1. Create the main solid structure [cite: 11]
union() {
cylinder(h=total_height, d=outer_diameter);

// Bottom exterior extension [cite: 14]
translate([0, 0, -bottom_ext_h])
cylinder(h=bottom_ext_h, d=hole_diameter + (bottom_ext_w * 2));


}

// 2. Subtract the 16mm center hole through everything [cite: 12]
translate([0, 0, -(bottom_ext_h + 1)])
cylinder(h=total_height + bottom_ext_h + top_ext_h + 2, d=hole_diameter);

// 3. Subtract the cavity to leave the raised lip [cite: 13]
translate([0, 0, base_thickness])
cylinder(h=total_height + top_ext_h, d=outer_diameter - (2 * lip_thickness));
}

// 4. ADD the Interior Ring with 18mm ID and 20.2mm OD
// This leaves a flat space around the centre hole
difference() {
translate([0, 0, base_thickness])
cylinder(h=int_ring_h, d=int_ring_od);

// Subtract 18mm from the center of this ring
translate([0, 0, base_thickness - 0.5])
cylinder(h=int_ring_h + 1, d=int_ring_id);
}
}