Customizable Fan Grill

This is a fan grill for various square fan sizes. This is particularly useful if you can't buy a grill for your uncommon fan size.

The attached stl's are rendered with the ellipse profile. They should be correct in size, but I've only tested the 140mm one.

Note that this doesn't work with thingiverse/Makerbot Customizer. Please use OpenSCAD's Customizer.

Customizer settings:
1. Ring height / thickness / spacing
- parameters for the circular elements

2. Spoke height / thickness
- p