I wanted to hang spools beneath my existing wire shelving. In searching for ideas, I came across https://www.thingiverse.com/thing:3551262 I decided to create my own because I wanted to modify the hole size and I don't like modifying STLs. 

I've printed variations with both PLA and PETG. Print with 4 parameters.

As provided, the spool holder is designed for ¾" (ID - OD of slightly larger then 1") PVC commonly found in big box stores in the US. The spool holders can be locked to the rod via self-taping 8mm/10mm M3 SHCS (socket head) screws.

I'm providing the source to my design. All dimensions are Fusion360 parameters, which should make it easy to modify to suite your needs.

I also created a simple hook to make hanging a breeze.