Axial SCX6 - Injora Center Caps

These center caps allow you to use the Injora after-market rims with center caps and still be able to take the lock-nut off and on without taking the 6 center screws out. 

Depending your printer there's two files - 1mm and 1.25mm, depends how accurate your printer is. I'd recommend 50% in-fill for the base so it'll hold up. 

The locking style topper is going to need a raft to print well; you can try upside-down with supports depending on your printer that might be better or worse.