just a quick model i did for cheap solar lights i bought from amazon. you can either just stick the solar panel on the pillar like i did or you could screw it down as well, but my print fits really snug. i used m3 screws and nuts to screw the whole thing onto my balcony.

used transparent petg from amazon for the print!

the pillar has a diameter of 11.2 mm and a height of 33 mm.