Here is a basic dice tower in two sizes Standard (20 mm holes) and XL (30 mm holes)

It's inspired by the matching shape boxes my kids had when they were little. 

I printed mine on the Creality Ender-3 V3 SE with a 0.4 mm nozzle with a 0.2 mm layer height.  No supports required but you may have some collapsed bridges on the inside (easy to clean and remove and won't be seen when the lid is on.