Firstly I made a half persian 4 in 1 chain using 2mm anodised aluminium wire, coiled and cut with aviation snips. The rings turned out to be about 10mm ID giving an aspect ratio of 5. Getting the weave right was fairly straight forward. Once I got my head around how the chain was formed, I set about trying to recreate it as a 3d model suitable for 3d printing, this took maybe upwards of 20 hours over 8 days adjusting wire size, aspect ratio and the angles of the rings... but finally... it worked!
The spacing between the rings of the 3d print works out at about 0.4mm (1.8mm wire and 9.9mm ID, AR5.5) whilst this may seem small, I scaled the chain down to 55%, 1mm wire and gaps around 0.22mm just to see if the rings would fuse during printing... they didn't :)
The Half Persian 4 in 1 chain maille sampler is available from my Shapeways shop.