Octa-B Braille learning tool

Design submitted on Pinshape contest : Envision The Future Design Challenge
https://pinshape.com/items/35262-3d-printed-octa-b-bearing

Starting from the idea that alphabet is easier to memorize if student can create and touch characters by himself, i tried to find a way to compose Braille character easily even for visually impaired people with a tactile tool. Since all characters can be created using 2 series of 8 different combinations, i designed 2 octagon parts with all dot combination faces, linked by standard roller-type bearing to allow relative rotation between both parts.

After trying many configurations of dot repartitions (same way like how to dispose letter on keyboard), i assume that the more practical configuration is when a half turn gives the opposite result, meaning that, in example dot 1-3 becomes dot 2 when turning 180 degrees the part. That point could be confirmed or updated if better proposal, however, i suggest to have the part with the screw on your left