Filament Spool Rack System - Stackable - Glueless

The “Filament Spool Rack” from ihateu3 (thing number 5865345) was exactly what I wanted, but it was made for inch sizes and since I live in Europe, I had to adjust it to millimeter sizes for the rods that go through the rack.
In the meantime, I have become the proud owner of a Creality K2 with a build plate of 350x350, so I could also print the parts in 1 piece.
I had also started to delve into Freecad and all this seemed like a nice practice path.
That led to me redrawing the entire rack in Freecad in mm sizes for a 12 mm steel tube (outside) that could be purchased cheaply at the local hardware store (Hornbach).

Parts:
A.stl can hold two rows of spools. Of course, you have to print at least two to hold the rods in between. My advice would be to keep a maximum distance of 1 meter between the posts, preferably a bit less (I keep to 75 cm because my rod is 1.5 meters long)

B.stl is a riser. If you were to put two A parts on top of each other, you would not be able to use the second ro