This model uses components from the A.N.O.T.H.E.R. Modular System.
Please go to that page for instructions on how to use the system:
https://makerworld.com/en/models/506203#profileId-421915
I've uploaded two print profiles with all the necessary parts to make this spool holder for the following diameters of tubes:
The provided parts in the print profiles or as .stl fit the standard 200mm diameter spools perfectly.
It would even fit the Bambulab or Polymaker's cardboard boxes.
I used six 28mm diameter wooded beams from my local hardware store (Hornbach). I cut them 550mm long as that would perfectly fit the spool holder under my desk.
You can have different lengths or even stack more spools on top of this by simply expanding the spool holder with more printed parts.
Hope you can make good use of it just like I did.
Happy Printing!