an earring in OpenSCAD

earring.scad

// main radius of the earring (mm)
radius = 16;
// how much it grows with each degree
grow_factor = 0.001 * radius;
// how big is the sphere in relation to the last iterated object
sphere_factor = 1.5;
// degrees from 1 to max_t
max_t = 310;
tt = [1:max_t];
// cheat the circle into a triangle
fn_ear = 3;
// generate a smooth sphere
fn_sphere = 100;

union() {
	for (t = tt) {
		rotate(a = [0, t, 0])
			render() {
				linear_extrude(height = 1, scale = 1, $fn = fn_ear)
					translate([radius, 0, 0])
						circle(r = t * grow_factor, $fn = fn_ear);
			}
	}

	translate([0, 0, radius * 0.1])
		rotate(a = [0, max_t, 0])
			translate([radius, 0, 0])
				rotate(a = [0, -max_t + 90, 0])
					scale([1.0, 1.0, 0.9])
						render() {
							sphere(r = max_t * grow_factor * sphere_factor, $fn = fn_sphere);
						}
}