Low friction filament guide

Made the filament guide proposed by the site anycubic I realized that it, even replacing the plastic pulley with an aluminum one, presented an excessive friction and certainly not pleasant for the Nema feeding the filament.
So I designed and built a new model that, thanks to the use of a pulley of adequate size (the greater the diameter and the better) moving on a ball bearing, makes the friction produced not a problem for the Nema.
Since the original anycubic filament sensor, albeit cute, com