Ichabod: Eyepiece Cap

I've made the eyepiece cap (the ring that keeps the lens in place) with a decorative design similar to the eyepiece itself.



Here—left to right—are the model, the unfinished casting, and the polished cold cast aluminum cap.

And this is the eyepiece with cap in place on top. I am quite pleased with how it is looking.

Ichabod: The Finished Eyepiece

After staring at the eyepiece prototype for a few hours I have decided that the foam relief is too pronounced, so I've replaced it with a much thinner material.

The new prototype is on the left, the cold cast aluminum part just out of the mold is in the middle, and the polished eyepiece is on the right. The cold cast is a dull gray until it is sanded to reveal the metal powder and polished. Next I will move on to the sculpting of the mask in clay.

Ichabod: Molding the Eyepiece

Continuing with the Ichabod eyepiece, I seal the outside with Bondo™ auto body putty so that the mold material won't leak in between the individual pieces of acrylic.

I hot glue the model to a small piece of Formica. Here I am hot gluing a paper popcorn cup down around the model to contain the rubber.

This is the model, cup and wooden dowel (to make it easier to demold and to save on rubber) ready for the silicone rubber.

The silicone rubber RTV (room temperature vulcanization) is ladled out with a spatula.

First I weigh out the white rubber base......

.....then I weigh out the dark blue activator, which is 10% of the base weight.

After mixing it completely with the spatula, the silicone mix is placed into a vacuum chamber to boil out any excess air. This picture shows the rubber mix boiling away (at room temperature).

Once it is vacuumed (deaired) the silicone rubber is poured over the model.

The next morning I demold the eyepiece, and cast it in a charcoal colored urethane resin. I sand smooth both the interior and the exterior of the casting.

Now for the decoration. Rather than add screws or bolts as I have with earlier steampunk eyepieces I have decided to add a design in bas relief. First I draw out the design with a black Sharpie™ on white paper, then scan it. Bringing it into CorelDraw™ I vectorize it and clean up the lines, then laser cut it out of green card stock to check the fit onto the eyepiece.

All looks well so I proceed to laser cut a thin piece of foam with mirror images of my design. The pressure sensitive tape on the back allows them to be attached and ready to mold.

Ichabod: A New Plague Dr Mask

I have decided to create a third version of the plague doctor mask, in addition to the classic historical style, and the steampunked Dr. Beulenpest, shown below.

I have had several requests for an extended beak, and that will be one of the modifications in the new mask. In my initial sketches (shown below) the mask reminds me of a crane, and so I am calling the new piece Ichabod, in a nod to the 19th century author Washington Irving and his Legend of Sleepy Hollow.

Before I can sculpt the new mask in clay I'm going need to build new eyepieces for it. Here I have lasered out several rings in acrylic sheet, which will be aligned and assembled using the brass rod. I slide each piece in the proper order over the three rods and use epoxy cement to hold them together. A stationary belt sander is used to turn the stepped bottom into a smooth angle. And here I've cemented a flange on the bottom to keep the eyepiece in place on the mask. Next step is molding it in silicone rubber.

Rhino Gas Mask: Eyepieces

I wanted to do something new with the eyepieces for this mask, different from what I'd done before. In the past I've used camera lenses, and several fabricated eyepieces, but they have all been circular. The rubber German gas mask that I pulled the pattern from also has round eyes, but after taping and making the 2D pattern, then cutting it out of leather and reassembling it as a 3D mask, the eye openings were no longer round. I could have easily inserted round eyes into the leather mask and it would have conformed seamlessly, but I felt that I had already done enough round eyes, and in this mask they even made it look a little goofy.

Thus I decided to go with the organic shape that the mask naturally took (seen in the shape of the clear lens above). Then I thought "Why leave the perimeter smooth?" and opted instead for a mishapen octagon. And one more innovation: Adding brass crossbars to protect the lens from breakage.

Above are the individual pieces: The base part cast in black resin, the clear acrylic lens, the cold cast aluminum cap, and the five brass rods.

And here is the assembled eyepiece for the left eye. The right eyepiece is a mirrored image. I fabricated both the base and the cap out of sheet acrylic. To the cap I added eyelets and machine screws, then molded it and poured it in cold cast aluminum. Now that is a different looking eyepiece!