Spool extender for dry boxes and filament changers

If you have a small filament spool, e.g. for holding 500g or 200g of a filament, it may not work inside of a drying box (like Creality Space Pi) or in a filament changing systems (like AMS, Qidi Box, etc.). This spool extender is placed over the small spool. Than it fits nicely into the above mentioned systems.

Another usage could be make the spool heavier. Heavy spool better adheres to the gears of the filament changing system (Qidi Box in my case) and resist the filament to jump up during rewinding/ejecting when the filament amount is small. This usage, though, can only work with narrow spools (like some spools from Sunlu).

If you plan to use inside of a dryer, consider temperature-resistant filament.

I used 0.4 nuzzle, 4 walls, Flash Forge PETG-CF.