I Know this is an ambitious endeavor but I'm going to give it a go. I want to scratch build one of these
what would i use to make the curved arches?
Gary
Cool project Gary.
What kind of span are you talking ?, I mean in actual feet and inches, not scale feet
You could use styrene, masonite, Gator board, a really good grade of 1/4" plywood, or MDF, just to come up with a few.
Mike.
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If I were building that bridge, I'd cut the arches from sheet styrene, then use strip styrene to add the flanges to it. You might be able to get away with using .040" for the arches, but I'd use .060", as I always have some on-hand in large sheet-sizes, as it's useful for large structures.The rest of the members could be done with the various structural shapes and square tubing from Evergreen, along with more strip material as-needed.
Use solvent-type cement to assemble it, and it will be strong enough for anything you'd care to run over it.
Wayne
Thanks for the quick replies.
The span from roadbed to roadbed will be 24". The cavern will naorrow ftom there to abut 4" on the bottom which will be20" below the bridge deck.
Im most concerned with the design of the lower arches. Most of the other parts can be made from existing kits and parts. I was planning on using a steal U Channel under the roadbed.
I Like the sheet styrene idea. I was looking at I-Beams from Evergreen but I'm not sure they would bend the way I need them to.
gdelmoro Thanks for the quick replies. The span from roadbed to roadbed will be 24". The cavern will naorrow ftom there to abut 4" on the bottom which will be20" below the bridge deck. Im most concerned with the design of the lower arches. Most of the other parts can be made from existing kits and parts. I was planning on using a steal U Channel under the roadbed. I Like the sheet styrene idea. I was looking at I-Beams from Evergreen but I'm not sure they would bend the way I need them to.
Hey Gary-
The Evergreen or Plastruct I-beams and channels do not bend along the axis you would want them to bend. I tried it; no joy. But, you could construct the arch with a series of straight bottom chords. When viewed as an assembled whole, the arch appears as a pleasing curve.
As for the steel channel deck . . . I think it is unnecessary. With support from the vertical members every 3", the styrene deck should be plenty stiff.
BTW, I'd use ABS instead of styrene. Personal preference.
Good luck.
Robert
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I would do it the the same way Wayne stated. That would easily make any arch you need
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
Why ABS instead of Styrene?