I thought it might be interesting for some of you to see what goes into creating one of my resin parts. For the Defender mask I decided to make one of the eyepieces similar to a camera lens, with a stepped conical inside. I built the prototype in layers of 1/16" (1.5 mm) thick clear acrylic sheeet. The drawing below shows part of the file I created in CorelDraw.
As you can see, the outside dimension of each piece stays the same, while the inside hole decreases in size as we move down the page. Some of the outsides are zig-zag while others are smooth. The red lines are the cut lines, while the blue lines are just for planning. The tiny red circles are for alignment pins.
Here are the pieces after being cut out with the laser. The parts on the left were extras I didn't use; the ones on the right were put together with three pins, and sprayed white to seal the cracks.
I then molded the prototype with blue silicone rubber and let it cure overnight. The next day I cast it in a charcoal urethane resin. I drilled holes around the perimeter (that had already been marked with the laser) and inserted twelve rivets to make it a bit steamier. I then remolded it and cast it in black.
Here is the finished part with pewter Rub N Buff™ added to the surface to keep with my black and silver color scheme. I'm not sure yet if I will use this one or recast it in a cold cast aluminum.
The small ½" (12.5 mm) diameter hole at the bottom of the lens sits fairly close to the wearer's eye, allowing him or her to see out, while keeping others from looking in.