Summary

This is my first attempt at a chainmail with circular links. The challenge is not so much in the design itself but in making it printable: curved bridges are hard. The bridges in this model start off straight, then the curve is supported by the first bridge layer. This is a fairly dense mesh, stiffer than similar chain mail with square links. The links on the edges and corners are well supported by adjacent links.

The OpenSCAD script is included, you'll probably need the nightly build, not the latest release (and even then rendering of a large mesh takes a long time). All dimensions are adjustable, but pay attention to gaps between links, for a dense mesh it's easy to make links merge. To get the bridging right, you need to set the line width parameter in the script.

The sample is printed on Prusa Mk2.5 with 0.4mm nozzle, 0.2mm layers. The printing is not particularly challenging but the adhesion has to be good: the print starts with a lot of small disconnected pieces, if one peels off the bed, the print is ruined.

Update: I posted a mesh with similar weave but hexagonal links, it's much easier to render and slice:
https://www.thingiverse.com/thing:3229872