I really liked Loosiu's hex model but it's only set up for 12 hexes. I created this in OpenSCAD to be customizable for any number of hexes between 1 and 19. The hexes are added in a spiral from the center out. I need to work out the math for adding more than 19 but I haven't done that yet.

I've included pre-rendered models for 3, 5, 7, 13, and 19 hexes. The hexes should be large enough to fit sharpies upside-down but the hex sizes can also be customized in OpenSCAD. The height of the box is such that a portion of a sharpie's cap should be visible above the holder when inserted upside-down (cap down).

In the print in the featured photo, I sliced at 0.2mm layer height and did a filament change at layer 12 (2.4mm) and at layer 176 (35.2mm).