From the Earth to the Moon was designed as a dual function model, first as a simple "string climbing" toy, and second as a ceiling fan light switch pull chain extender for my grandkids. The design incorporates a "dual spool mechanism" to produce the string climbing illusion. Toys utilizing a dual spool string climbing mechanism have been around for many years, and in my younger days I disassembled more than one of these trying to figure out the "magic" of how the toy climbed the string. https://www.youtube.com/watch?v=YrwbVuMi7WQ https://www.youtube.com/watch?v=gkRdIg3Lai4 This model uses press fit assembly for the dual spool, and threaded assembly for the body. You will need to purchase some string or heavy thread that minimizes fraying and glue. As usual, I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to ask as I do make mistakes in plenty. Designed using Autodesk Fusion 360, sliced using Cura 2.3.1, and printed in PLA on an Ultimaker 2+ Extended and an Ultimaker 3 Extended.