Easy Print Prusa Z Couplings

My friend and I were putting together a Prusa from Clonedel parts and had a lot of reliability problems with the couplings that link the z motors and threaded rod leadscrews. We tried printing some of the couplings already uploaded, but the printer was not yet working well enough to make them. These couplings have a very simple geometry that enabled them to be printed on our humble machine. Probably not too efficient material-wise, but they definitely do the job.