PVC pipes are a great lightweight and inexpensive material to make filament spool holders with. This project cost me less than $5 and took a matter of minutes to assemble. Even better, if I'm not satisfied with it's current look or function, I can take the PVC apart and redesign it.
Step 1: BoM
1/2-1" PVC pipe (I used three 5" pieces and four 3" pieces, Lowes/HD will do this for you)
PVC T connector (2)
PVC elbow connector (2)
Step 2: Base
To make the base of the filament holder, attach the 4 smaller pvc pieces to the T connectors horizontally. Attach a 5" piece to the vertical opening of each.
Step 3: Holder
Attach the elbow connectors to each of the base legs and then add the last 5" pvc piece. Slide on your filament and attach the other leg using the last elbow connector.
Step 4: Done!
To make a filament holder that can accommodate more rolls, increase the lengths of the pvc pipe cuts and make sure to make the base legs longer as well to account for added weight.