Thank you very much for your comments.
I have finally finished my project.
As a Rubik's cube it works quite well but when used as a spinning top it loses stability (something I was afraid of), however, I think it is possible to correct that with some strong magnets. This implies redesigning some pieces, but I will leave that for a second version (second project).
In spite of this I was quite happy with the result.
I thank Jeremy Erazo and Gerardo Lizama for their cooperation with the printing.