Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3003912.

The grooves push into the center of a pool noodle so no glue is required. I print this straight up and down with a brim of 20 lines and 3 layers. This probably isn't needed but for me keeps the rod from falling over accidentally. The whole for the connecting screw is thread tight so you could probably get away without a nut, or use an M5 nut for the end.