Attempted to make a Cuirass and Made three versions one Thin and other with 1m thick walls and lastly one without any holes if anyone is interested. Didn't know what to name it, it has many names.

Cuirass piece of armor consisting of breastplate and backplate fastened together.

Plackart (also spelt placcard, planckart or placcate) is a plate reinforcement that composed the bottom part of the front of a medieval breastplate. They were predominantly worn in the 15th century.

Originally Uploaded on Thingiverse https://www.thingiverse.com/thing:6001723

Enjoy!