This is slightly over engineered modular Filament Rack made out of 3-4 parts. It uses ½ inch EMT conduit (about $5 each @ Home Depot)

I used EMT conduit in mine because it's strong and doesn't bend easily. Prior to the pictures you see I had the spools sitting on only 2 sets of each part and EMT conduit survived with very little bending for over a week until I printed another set to give myself a little peace of mind; that was 16 spools of filament with very little bending. If using ½ inch EMT I wouldn't go past 10 spools for safety; also at 16 spools one side was supporting close to 50 pounds of weight so that seemed a bit much.

You can go as many levels as you want; in pictures you see 3 levels and if you want more just print “Middle Point” and “Riser” parts per level.

I'm including STEP files for 0.5inch EMT version so you can make the holes bigger for whatever you want to put in it or just leave a comment below with whatever diameter pipe/stick you want to put and I'll resize it for you.

Note: There is very little room to play with snapping the parts together because too much play and they begin to wobble; I printed mine with Sunlu White PLA and while it worked for me perfectly it may not be the case for your filament.  If you're not sure if it'll work print “Middle Point” and “Riser” parts first and see how they snap together if they do then everything else will too.

Edit1:  Added 2 additional versions; one with 26.4mm holes (Slightly over 1 inch) and one with 34mm holes (slightly over 1.3inch).  I would print “MIDDLE POINT” and “TOP” parts stronger with those as they become weaker with larger holes; do more walls / higher infil.