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        Discussion Fixing a Wing Like This???

#1 DocMac Oct 07, 2012 09:19 AM

Fixing a Wing Like This???
 
I am still in that quandary stage of reviewing planes, getting confused--which one, which one, which one? It dawned on me that some planes, such as the one pictured in the link below, have a carbon spar going down the length of the wing. My question is this: if I bash in a wing and need to repair it, does the presence of that spar create a problem? For instance, if the center section of one of the wing panels is damaged, and the carbon spar wasn't there, then I'd repair it like any other woody. But, with this spar, will a little repair require complete disassembly of the wing due to the presence of this spar?

http://www.espritmodel.com/prelude-25e-f5jales-arf.aspx

Thank you!
Brian

#2 BigSwede Oct 07, 2012 10:16 AM

I guess it would depend on how bad the damage was. If you just crunched a couple of ribs, I would just remove the covering from that action and replace the damaged ribs. If the carbon leading edge was damaged you'd replace that too. If the spar was broken as well, the repair would of course be more involved. I'm thinking the spar is a tube, not a rod, so a section smaller tubing could be inserted into the spar and reinforced that way. This would also insure that the spar was kept straight. Now you would just make certain not to introduce any twist. Seems like it would be fairly simple to repair actually.

#3 ferincr Oct 07, 2012 10:27 AM

I'm going to jump in with my comments...
For any repair already created a problem:D:D:D, but I guess I know what you mean...
I used to build woodies from scratch, and I done quite a bit of woodworking so I guess that you are thinking with a woodie, if breaks, just cut/splice/ sand, cover/ done.
Lately I'm more into composites and you need to have other aproach for them, but the principle is almost the same (a bit more messy and sticky until you yet the yist of it).
I just repaired a fully molde wing using a combination of techniques
http://www.rcaerotowing.com/forum/sh...-advice-needed
I guess the answer to you question is depends on the type of damage but, the procedure would be pretty similar as if was wood, clear enough of the spar to be able to splice it.
I think composite repairing is pretty much the same as in wood (may be even easier) it just requires a different set of tools/materials and a slightly different approach but not much.

#4 ferincr Oct 07, 2012 10:36 AM

I agree with BigSwede,
I find that composites is easier than wood.
My father was anincredible woodworker, I just picked up whatever stuck to me over years of hanging aroud in the shop, but there is no way around you have to be PRECISE there is no other way around.
Composites in the other hand I find it more like metal working, it's a bit more forgiving, you can do it and then snd/trim around afterwards, it allow you to add a bit or take away if needed to.

#5 jaizon Oct 07, 2012 05:15 PM

I know this thread is about repairs, but you might want to consider this plane. I have seen them fly and they are excellent!

http://www.polecataero.com/oracle-93...plane-for-ales

#6 DocMac Oct 07, 2012 06:26 PM

That Oracle plane by Polecat looks awfully tempting!

#7 lincoln Oct 07, 2012 08:36 PM

I wonder what the performance penalty of not having a d-tube is? Certainly it ought to make repairs easier.

A tube spar isn't very optimal, so it either weighs more or isn't as strong.

#8 aeajr Oct 08, 2012 03:11 PM

The key point about composite vs wood spar is the wood spar is more likely to be damaged from over stress or similar things. A carbon reinforced wood spar or a carbon tube spar is less likely to be damaged so you are less likely to have to fix it.

However either way, if you break the spar of any wing you have done extensive damage. In order to fix a spar you can't just glue the ends of the break together. The repair techniques might be different due to different mateiral, but if you break the spar you have to rebuild it and that is never a minor repair.

Fixing a tube spar might be a matter of getting a smaller tube and putting it inside the main tube spar and gluing it in then patching teh joint with carbon cloth. A wood spar would have to be extensively rebuilt but, again, the concept is the same. Span the break, spread the load, get it back together and make sure it is straight.


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