So, I started off with the gear rings from this person: https://www.thingiverse.com/thing:6138051, who remixed it from this person: https://www.thingiverse.com/thing:2850756 who remixed it from this person: https://www.thingiverse.com/thing:2105705

I found the solution to the connecting problem was: Shutter Fidget by 3d-printy on Thingiverse: https://www.thingiverse.com/thing:6517951 It takes some force to assemble - I line them up and step on them.

I also hate to wast material., so I incorporated 0.5mm 'feet' inside each print to keep them from slipping during printing without resorting to a raft.

Severe elephant footing will ruin project. If it is slight - flip one gear so that fattest parts are not on same side. If they jam at one spot it might not be the teeth, but the inner opening being out of round.