String "Climbing" Ball is based on the dual spool design of this thing: https://www.youmagine.com/designs/string-climbing-mechanism. It doesn't really climb the string, it just appears to do so. Consisting of 8 unique parts (10 total), and only requiring the purchase of embroidery floss, once assembled String Climbing Ball puts to use the "String Climbing Mechanism" and further illustrates how string climbing toys such as these, some over 100 years old, operate. And as an added bonus, as shown in the photograph, the lower ring doubles as a display stand to keep your String "Climbing" Ball from rolling away when on display! Designed using Sketchup Make 2016 and printed in PLA on an Ultimaker 2 Extended. Video of prototype is here: https://www.youtube.com/watch?v=0bZZ2xgOE84