This is a simple filament spooler.
It consists of multiple pipes.
Thick pipes are made of "ERECTOR" pipe system. This system is very popular in japan.
Two thin pipes are 9.5 mm diameter stainless steel pipes.
And I made a connection part(white part in the photo).
type of bolts and nuts to fix connection part
bolt x2 :3 mm diameter , 20mm length
nut x2 :3mm diameter
The reason why I add two stainless pipes is "ERECTOR" pipe is covered with resin and the friction resistance is large.
To reduce friction resistance more, two pipes are used. This is pretty effective.
This would be useful for filament reels with an inside diameter of 55 mm or more.