15 PSI wing cores

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wtsidney
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Joined: Wed May 09, 2012 6:46 pm

15 PSI wing cores

Post by wtsidney »

I'm dreaming of cutting my own wing cores for SSC and Limited B ships. The local lumber yard stocks 15 psi rigid foam insulation. I realize that 25 - 40 psi foam is ideal.

But the 20 dollar question is how much strength does the foam contribute to a wing?

Less dense foam would be more susceptible to hangar rash, but the flight loads should still be supported by the fiberglass top and bottom spars and leading edge. Could add a full layer of Bi-Di tape for additional armour.

Any thoughts or experience? Expect this has been tried before.
Bill Sidney
Round Rock, Texas
RCCA 1036
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boiler
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Re: 15 PSI wing cores

Post by boiler »

When I started, all I could get was 15# foam. It is lighter but weaker. If you don't need extra weight it will fly better. If it comes up light, better add weight in the form of armor. When I started we used rip-stop nylon for covering held on with water based polyurathane finish. That stuff was really tough but weighed more than tape. Not as much as bi-di tape. I got mine from sail manifactures.
Bob (Longhaul) Loescher
rcca# 621 RC Combat Geezer
Bring those planes in closer where I can see them.
[url=http://www.rccombat.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=11380][img]http://www.rccombat.net/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=11381[/img][/url]
Quickdraw
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Re: 15 PSI wing cores

Post by Quickdraw »

15 PSI would work in SSC with exrta bi-di. In B you would need to add strength. I would add another fiberglass spar on the bottom a few inches off the TE. I would also glue on a hard balsa trailing edge.

You can also try flying combat at a lower altitude. The air is more dense and that should help strengthen your wings :D
David E. Ebers Sr.
RCCA South Central Rep
Quickdraw #338
wtsidney
Posts: 30
Joined: Wed May 09, 2012 6:46 pm

Re: 15 PSI wing cores

Post by wtsidney »

Quickdraw wrote:
You can also try flying combat at a lower altitude. The air is more dense and that should help strengthen your wings :D
But High Impact aerobatics are spectacular from the higher altitudes.

Sounds like the foam provides quite a bit of the wing's strength - hmmmmmmm. Might try some different armour and additional spars until I source some denser foam. Anyone try the stiff - Digital Imaging laminate as covering? I'm thinking stressed skin.
Bill Sidney
Round Rock, Texas
RCCA 1036
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