I reduced the size of the hinge with respect to the original model.

Also you need to download and print the clamp from the original model:

https://www.printables.com/es/model/241692-filament-splicing-jig-remix

The small tube is to prevent the joints from breaking when winding the filament as well as to validate the filament diameter, I clean the joint until the small tube passes through it with a slight friction, enough to stay in the joint but easy to slide when the filament enters the printer. The inside diameter of the tube should be printed between 1.8 and 2mm.