Dowel: Modular bottle rack

Max bottle diameter - 84mm .
Use 3/8 (9.52mm) dowels to connect printed hexagons. To use 10mm dowels scale XY to 105%. If the dowels do not fit snug, scale the model up or down in XY.
Depending on the orientation of the hexagons you'll need minimum 2 (top/bottom) or 4 dowels per hex ( 1 top/3 bottom, 2 top/2 bottom, or 4 bottom configuration).

While on the front side dowels should be flush with the hexagons, on the back side they can be optionally extended (5-20mm) to offset the hexagons from the back wall for easier bottle placement.