This is JSpeed's Modular Hex Bottle Rack, modified to be parametric in FreeCAD so you can choose the edge-to-edge diameter of the hexes (in a spreadsheet cell).

This differs from just scaling the STL in that the joining holes and thickness etc all remain the same; you just choose the diameter of what you want to fit in it and it works out how long the sides need to be.

Also included is an STL for a 75mm version of the original hex. I've not included an STL for the joining pieces as you can use the original (or regenerate it yourself in FreeCAD).