This is a custom made spool holder designed specifically for 3DNet PLA XL 3kg Spools.
It should also fit nicely for other spools that has an outer diameter of 30 cm or less and an inner diameter of 2.5 cm or more. Maximum width is about 12 cm.
The model is made as minimalistic as possible for fast printing. I was able to print all three parts in less than 2 hours with a 0.8 mm nozzle.
20% infill and 5 top/bottom layers seems to be more than strong enough with 3DNet PLA.
The joints have a 0.2 mm margin (0.1 on each side), makes for a snug fit in my case.
Print two sides and one rod.