Bend concentric octogons by scaling the octogon file size in DIWireWare. We tried 100%, 125% and 150%.
Make sure ends of bent arms are all clipped to similar lengths.
We soldered the first seam with two arms laid flat on the same plane.
You can then prop the arms up and clip all four together to finish soldering. Once the solder cools, flip the base right-side-up and rest the smallest octagon on the arms. Solder all four joints and repeat with the larger ones.