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For those of you who have seen the 1:192 refit plans I posted, you know they are pretty big.

Assume for the moment one wanted to acutally build one that size. What would be a good material for framing the saucer?

You would really take a hit because of the need to cut out part of the frame where it attaches to the neck to make room for the impulse engine.

It looks like standard 1/4" plywood would not be strong enough. 1/2" might do but it would be too heavy. Maybe a good quality 1/4" birch plywood might cut it?

Does anyone know of any plastic that might do the trick? Ideally it would be something that can be machined (including routed) with melting but not too hard to prevent sanding to shape.
 

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Lasercut acrylic might be strong enough. But, if I were to build a large-scale E-A (and I might just do that eventually :) ), I would make an armature from either welded or bolted aluminum. The original had an aluminum plate shaped like a donut inside the saucer. This was further stiffened by welding on an aluminum tube bent in the shape of a circle (i.e. a torus or true donut) that was gusseted to the plate. All this was secured to a solid aluminum plate inside the "neck" or dorsal connector. That was welded to the top of an aluminum tube inside the secondary hull. The frame was finished by welding two more aluminum plates at angles running up through the middle of the engine pylons.

Yeah, it's a lot of work -- but you need a sturdy frame that can stand up to anything and really last.

I'm a firm believer in aluminum frames for large models. My 6-foot Galactica replica has an armature made from MIG-welded heavy-duty aluminum fence posts! :)

And, BTW, from what I have heard, the lasercut acrylic armature designed for the 5.5-foot TOS E replica did not perform as expected. I don't think it was strong enough for the task at hand. And it was certainly not stiff enough to do the job. Plastic just might not cut it -- you need something that simply won't flex.

Hope that helps! :)
 
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I feel i have to agree with the single acrylic sheet as an unsuitable medium, except what about making up some laminated sheet acrylic.
Maybe a laminate of 2 or 3 sheets may do the trick?

I had in mind to do an epoxy/fiberglass one later this year or early next but also using carbon fiber along with glass cloth in the layup.
Using a small 'U' shaped trough running around the saucer interior with carbon laid over that, then doing the same kind of thing throughout the rest of the ship as strongpoints where the greatest stress occours.

Idea i had was a captive nut and bolt together armature, also bound to the laminate so at least i could take the beastie apart for storage as well.
It may work or may not, have to do some 'test to destruction' mayhem to find all the details but that's all for much later.

Go easy.

John P said:
Tritanium.
Or neutronium? ;)
 

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star-art said:
...I'm a firm believer in aluminum frames for large models...
Interesting. The original question about framing mat'ls had me thinking armature-wise, but now I'm thinking that a carbon-fiber, hard shell construction might be a possibility. That is, make the model surfaces themselves be the load-bearing structure. The number of fiber plies(the mat'l thickness) can be adjusted, to meet local strength requirements.
 

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Seriously, if you can construct the fiberglass pieces accurately, expandable foam with small pockets blocked out would probably be the most economical, efficent way to go and would maintain the perfect shape without danger of collapsing. It also would be relatively lightweight and inexpensive.
 

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toyroy said:
Interesting. The original question about framing mat'ls had me thinking armature-wise, but now I'm thinking that a carbon-fiber, hard shell construction might be a possibility. That is, make the model surfaces themselves be the load-bearing structure. The number of fiber plies(the mat'l thickness) can be adjusted, to meet local strength requirements.
I'm thinking that at 1:192 scale a combo of a basic tack-welded steel armature(nothing too complicated, something simple yet well designed like Krako's armature for the PL 1:350th 1701 Refit Enterprise) combined with some lightweight expandible foam would be a practical solution that would both make the ship strong and avoid future warping that could occur around a simple metal frame(nobody would want to make a complicated metal frame, plus fiberglass, resin or plastic could still warp around even a complicated metal frame without contour support).
 

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How about cast rodinium? It'll stand up to anything short of a Romulan plasma weapon!

And then there's always transparent aluminum . . .
 
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