Rope Driven Gyroscope
It is a toy that consists of a disk with two symmetrical and eccentric holes through which a closed string passes.
When the ...disc is rotated, the string is wound on both sides and when the strings are tightened it unwinds and rewinds, giving rise to alternative turns in one direction and the other.
20/05/2019: Para los que no tengan anillos metálicos pueden imprimir un par de aros descargando el fichero publicado en: https://www.youmagine.com/designs/anillo-para-final-de-cuerda
3d model print parameters
Print the disc with rigid filament (example PLA) without supports
You will also need 100 cm of 2 mm string which, with the help of a needle, will be ...inserted through one of the holes in the record, then through the other and finally the ends of the string will be tied so that it cannot come off.
The disc should be placed in the center of the string and so that it does not move, I recommend putting a drop of super glue near the holes.
I also recommend putting two rings of those used in key rings at the ends of the string to avoid that when it is wound it leads to squeeze the fingers that hold it.