US Navy Diving Helmet

The printed components I used to make a costume of a MK.V US Navy diving helmet for a Hallowe'en party. The helmet itself (the dome and collar piece) was EVA foam. Best option is to paint the whole thing copper colour, then brush paint the seams with silver to simulate the soldering. I used a reflective tinting film on the windows to make it spookier.

It'll need some nuts and bolts to make the hinges and to look authentic. A big wingnut for the front window is good as well, but I didn't have time to find one.

I used the adjustment knob on the front to adjust a speed controller for an internal fan, pumping air in through the two hose connectors at the rear to keep myself from suffocating. It gets very stuffy inside, and ventilation is definitely needed. Don't build this without active ventilation!

The main head dome is 270mm in outside diameter, and the neck connection is about 220mm diameter. I've included a .STEP file of my original drawing, and a pair of .STL files of the dome and collar, but these are untested and I can't vouch for them.
I have also quickly created a DXF foam pattern for the EVA foam. When I made mine I did it more or less by eye, so I can't say this pattern is perfect, but it should be a good jumping off point. Use contact adhesive, and good luck!