I was encouraged to finish them and thought it would be fun to work in a mechanical shutter.
With the exception of a few screws and nuts, a poly-carbonate lens, and a spring, everything here is fabricated from sheet, rod, or square stock. Or leather (eww).
The straps are adjustable and their is a spring mechanism on the back of the strap to take up the slack and keep a firm but gental grip on your face.
The Iris shutter is admittedly not a diaphragm iris and I have been scolded endlessly for this and the slight gaps where the leaves come together. To this I must ask what practical necessity, fulfilled by an aperture diaphragm, is not suitably filled by this design?
I think in any steampunk build the end result is an aesthetic pursuit. To that end, this iris is pretty slick (if I do say so) and far more robust than the diaphragm designs I tried. I'm not griefing other styles, it's just odd how much opinion I get on this subject.
Like a lot of my work, this piece has an ugliness to it. Part of that is by design, part is the result of these being a working prototype. The majority of this piece was kept thoughout several design changes, re-engineerings, partial rebuilds, shop explosions, etc. Waste not want not. As I solved problems the work was redone with the final result showing the trauma.
Even so, these goggles are incredibly robust. Hard solder was used throughout as well as hand-formed rivets whenever possible. On the iris' driver ring, for instance, the ring is a strip of scrap copper with the ends brazed to form the ring. For each leaf there is a pivot point that connects the ring to the leaf's connecting rod. That pivot point engages the ring in a journal made from a small length of copper tube (to make the bearing) which is brazed to the inside of an inch long brass strap, which is held to the driving ring with two hand-formed rivets.
So, while it looks beat up it's actually very sturdy.