I made a set of bookends from ¾" pipe and fittings with a wood bracket and wanted to see if I could do it in a 3d print.

Since it is 3D printed it is light one can put non sliding feet on the bottom (or a flex/tpu base thin layer?)
changed the base so the books weight will hold the bookends still.

Print in PLA for tolerance reasons unless you don't mind post cleanup from PETG stringing.

Use supports inside the 90's 

If you have problems with the nipples slipping or knocking over use inside support brim.

There are several files so you can do it in sections as well as change colours.
I included it in a complete model as well for those that do not mind using lots of supports and post cleanup.