Getting to 36 seemed too straightforward to be theory optimal but I can't figure out anything better. Hoping to see some magic to squeeze more silver out of my silver. The last cycles puzzle was too daunting so I'm glad that I was able to get a solve matching the best I could calculate out. 

I think I spent most of my time figuring out how the piston can complete it's job in time and dodge the hex arms. 

I expect I have 1 extra triplex, a unnecessary piston, and two extra track. That would put it at 470 somehow, but at least I got mine down from an initial 635 cost.