1) Prints entire set on 1 bed. Just use the "Complete_Revised.STL" file (see Update below regarding key).
2) Functional chain prints in place -- No need to assemble chain
3) Removes internal surfaces of original model that weakened device and could cause print failure.
4) Remade key to improve printing ease.
5) Remade flex pin for improved durability.

Original model is great, but this should make it better.

I advise printing with a large brim to keep the chain links in place during printing. One of mine above broke free early on but somehow still completed the print, just a bit warpedly.

Update: Look for the new key file. Hoping to strengthen the "tooth" by having layers run diagonal to the axis of rotation. Will update combined file later; for now it still has the weaker design.