Do any definitive articles, accounts or even transcribed anecdotes exist concerning the construction of the titular prop from "The Doomsday Machine"? I plan to model the "weapon" in digital form, one that I will share with the 3D community for use in their various fan projects. If I had some insight as to the materials and methods used on the physical prop, that knowledge might help me make it a bit more screen accurate. The "holy grail" of background information would be snapshots of the model under construction, before the crew filmed it. But since "behind the scenes" snaps of the Enterprise are somewhat rare themselves, I realize there is little to no chance photos of the DDM miniature exist. Still, it does not hurt to ask.
I remember the recent YouTube interview with Norman Spinrad discussing the episode and his comment about the prop supposedly being a "wind-sock" dipped in cement. But I suspect that observation was said purely tongue in cheek. A concrete based "spacecraft" model would be far to unwieldy (read: heavy) to film suspended upon wires or even upon a support rod. Plus, it looks nothing like concrete. Theorizing from screen captures, I suspect the "cone" was constructed from multiple, overlapping sheets of cardboard, probably painted and covered with a layer of translucent, wrinkled cellophane to give it an irradecent "shimmer". These pieces possibly covered a frame of chicken wire. The various side on "panning" shots as well as the slow "zoom" into the "maw" appear to be static, photographic cutouts. Notice how the perspective never changed in those shots. Only when the artifact "swung about" to face the audience does it appear the camera crew used the model itself rather than a photographic cutout.
Of course, all this is merely wild theory based upon final production footage. I could well be wrong.
But any information anyone can relay I'll greatly appreciate!