This is a spool holder that I designed. It is completely modular and can be as long or has short as you want. I designed the holes to fit ¾ ID PVC Pipe which can be found at any home improvement store. The actual size of the hole in the print is 26.6mm so anything with a diameter of that size or slightly smaller should work.
Main Print Settings I Used:
Filament - PLA
Supports: None
Infill: 20%