Thanks, everyone, for the encouraging words. Finishing the arms today and then it's time for the full reveal! Had a difficult time coming up with a suspension system for the arms but I'm happy with what I came up with...a huge door spring, a pool noodle, some coated steel cable, and a couple cat litter jugs later- the arms are attached!
I just want to say...this is one of the most inspiring threads I've stumbled upon in a while. It's really made me start to think about projects I have always considered "impossible" and ask "maybe this is doable."