Another spool shelf!!
Yes, but design, practical and modular!
To assemble it, I imagined the design for 20mm diameter tubes. I recommend a maximum center distance between the brackets of 80cm, to avoid bending. Beyond that, you must add an intermediate bracket.
For an additional shelf, you will just have to place a bracket just above the other in order to mark it.
The drilling distance of each bracket is 190mm.
To determine the length of the tubes, you will have to add 10mm to the fixing center distance.
The superposition of the shelves does not hinder the handling of the spools.