I then needed to draw out a basic design that I could build...
Here are the scribblings where I was trying to visualise the way they would work.
Here you can see the rather dubious hold-it-in-the-hand technique
There's a bit of a Cyberman vibe going on here.
Making the mounting plate
To make this from steel is not easy to guess, so I had made a paper prototype first.
This is on the right
To work out how far these needed to be apart, I had previously measured the distance between the centres of the two eyeballs in the neutral position.
The eyelids just need to be strips. Here is one freshly cut from the cardboard tube.
Here it is being tested.
Slightly closed for a dopey look
These paper models were all I needed to work out how big the eyelids needed to be, then cut them out from steel plate.
It's hard to see here, but the 60mm distance between the eyeballs measured earlier is shorter than the 70mm needed for the gimble. This is why the plate needed to be folded.
Cutting out excess metal.
Using the vice to fold the plate fully.
From another angle.
And swapped upside down.
And finished off with a damn good beating on the anvil.
The finished centre fold.
This was tight, but needed to be opened out. A crow bar was easiest
The distance between the centre of the two gimbles is 60mm, to match the distance measured earlier between the eyeball centres when positioned in the mask.
These flaps had been cut out with a metal cutting blade in the reciprocating saw.
The flaps were shaped using a hammer head as a former.
Paper prototype recreated in metal :)
Seen from the front.
Here is the face with eyeballs in place (with irises drawn on for testing)
The eyelid strips are longer on one side to act as levers.
This is the basic mechanism. It needs hooking up to controllers and needs eyelids attaching. The metal eyelid is the equivalent of the "superior tarsus" of a real eyelid. The skin is likely to be made from leather