Gear bearing keychain fidget (keychain ring not included)

I wanted a keychain fidget version of Gamma4D's Perfect Gear Bearing v2, so I added a post that goes through the center and gets held in with a split ring (not included). The post is large enough to hold the center gear in place while the others spin around it. The original advises using 0% infill for the gear bearing. I welcome printing tips for maximizing the strength of the center post.