guide rotating filament holder for TRONXY

Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2539563.

Directional rotating pulley for filament. It is positioned upside down on the printer frame and the filament is passed over this pulley. This ensures good feeding of the filament. Filamet can be placed behind the printer on the desk and does not burden the printer frame. The rotating head follows the printhead.