Snap-on stand

Problem

I need more spaces for my gadgets, but I also want my graduation bear have a place to display.
I think allowing my graduation sit on the edge of my book shelf is a good idea. Unfortunately, the self is made of standard 20mm thick wood board. They are too narrow for a stable and safe display.

Task

Design a thing that allow me to make good use of the space, main goal is to provide a surface big enough for stuffed toy being displace stably.

Design

This design is designed to snap fit a 20mm board, and provide a round surface of 120mm diameter.