This is a two tier spool rack for storing spools of filament using 1/2" PVC pipe as the cross members and uprights. In the example prints the gray electrical PVC was used to coordinate with the gray carbon fiber printed material.

Parts needed:

(4) Printed Spool Rack End - this file/thing
(4) 1/2" PVC pipe as uprights (minimum length 7.25" [8" suggested])
(4) 1/2" PVC pipe as crossmembers (desired length of rack - 21" was used in the example)

The original design idea for this came from Artobot when visiting his place to do some printer repairs. The design was modified to fit my exact needs but is being shared in case others would like to print spool racks. Keep in mind the 7.25" uprights that were used in the example are just barely tall enough to fit the Proto-Pasta cardboard spools on the lower tier. My space requirements needed to have this in order for the rack to fit on the shelf it was going on. Suggest using a taller upright to fit plastic spools, additionally a taller upright will allow placement of the spool unto the lower tier without having to cant the spool during placement.

Ends can be used as handles nicely due to the slope on the inside of the part. Recommend gluing the ends if doing this as bottom may fall off if your friction fit isn't tight enough.

Updated 26 February 2021.  Added Stackable Spool Rack End which allows for building of racks higher than the original 2 tiers. For a 3 Shelf rack you'll want all the two tier pieces mentioned above plus 2 of the stackable spool rack ends and 2 additional crossmembers.