Summary

This is a slightly modified version of https://www.thingiverse.com/thing:4609599. I made the underlying shape convex instead of concave, but doing this required me to change the shape of the bullseye geometry so it could print the bottom row without supports. This enabled the print to complete in just under 22 1/5 hours using a print speed of 90 mm/sec and a layer height of 0.200 mm.