Used an already great project and resized the holes to Ø18mm, to use some rods that I had lying around.

Added some extra hole grip design for wooden rods.

Printed upside down with supports only in beams. Honeycomb doesn't need them (bees are great engineers ;) ).

Link to a box / shelve support for Ø18mm rod - https://www.printables.com/model/791270-box-shelve-support-for-modular-spool-rack-o18mm/files 

Good prints!