Null
I designed this in an instructable for this contest but could not get it to load from the instructable itself. The design is simple, its bases are printed in 2 pieces (gray parts) that have moveable parts (rotating arms) the mid section (yellow parts) that supports and slides together and made to keep it all together. You will need to purchase bearings, ball bearings, and a spring. Here are videos to assembly and how it works. https://www.youtube.com/watch?v=9u2xAMTUqoE&t=4s https://www.youtube.com/watch?v=x3zOHWyoXhI