Version 2 - adds support for round grids, adds a parameter for outer wall thickness, and allows for quick adjustment of $fn (facets) on circular grids.

Summary

Hexagonal grids are a nice design tool when printing. They are regularly used to maintain strength and rigidity while lowering overall weight and material usage. They are also used as a design element. As such there are numerous methods to create and add hexagonal grids to your designs. A common method is printing hexagonal infill with no top and bottom layer. This works very well in some instances (grid oriented in x-y). If your grid is rotated it is difficult (sometimes impossible) to use slicer settings and achieve the same effect. 

The attached OpenSCAD script will generate a circular or rectangular grid of hexagons of arbitrary size and wall thickness. This can be further modified within your designs or can be used to generate a quick .stl to fill holes in an existing component with a nice hexagonal lattice.

There are several hex generators available online already. Compared to other OpenSCAD versions this script renders more quickly due to use of the excellent Belfry OpenSCAD Library. It also centers the hexagons automatically within your grid. I find this more aesthetically pleasing than some other options. 

Usage

Note: The Belfry OpenSCAD Library v2 is required. Details are included in the OpenSCAD file

Save the attached file “hex-grid.scad” to your computer. Then open and modify either of the example lines (create_grid or create_circular_grid) with the parameters of your choosing.

If you would like to use this in other projects (recommended), then save the file to a folder located in your OpenSCAD library path. Comment out the last line of the file. Then you can include the file in any project by adding include <folder/hex-grid.scad> at the beginning of your project script. Simply call create_grid(size,SW,cell_wall,frame_wall) or create_circular_grid(diameter,height,SW,cell_wall,frame_wall,$fn) in your project