Yet another Spool Holder

This is my own spool holder design that has several advantages. First, it has a curved rail that fits over an standard 608 bearing that holds the spool in place and avoid the spool being trapped between the 608 bearing and the main body. This happens to me all the time because the spool walls are thin.
The central rail can be fit within an air-proof box and very conveniently align the spool. The sided bearing caps hold the bearing in place and save PLA filament
You can also use it without the central rail. This piece is optional