Could you please post a schematic of the system and helmet positioning?
Since I´m building myself a Mark-4, I have the basic same idea as you for the hinge system, but would like to compare projects.
I'm following this thread with a lot of interest, it is simply amazing what you can do wen you actually understand what you're doing
I have the hinge system ready myself, almost identical to yours, but was still trying to figure out how to motorize it... I can´t wait to see your project...