Composite or Built up which is best???

[OnTheEdge]

	Quote: Originally Posted by Mithrandir
	I can repair most composite structures... It is the paint job on a compy I could never reproduce!!

That's why they make graphics!

Sounds like you have quite a grasp in the composite realm. Hope some day you find some time and design your own composite plane. A build thread on here would be awesome. I'd love to see molds of a fuse half. Plus have someone explain to me how "painted in the mold" actually works.

[shannah]

	Quote: Originally Posted by Wayne
	Albert, Thank you for posting that. I was just about to say the EXACT same thing.

Sorry guys, just relaying my personal experience.

Maybe I can clarify something. I think the composites transmit high frequency vibes across the airframe more than wood frames, but the wood airframes that I have experience with shake like crazy at the lower freq's. I have no explanation for this. That's what I have seen on my Dalton and on other Columbo Andersons. Never held a Carden so I can't comment on that.

[Mithrandir]

	Quote: Originally Posted by shannah
	Sorry guys, just relaying my personal experience. Maybe I can clarify something. I think the composites transmit high frequency vibes across the airframe more than wood frames, but the wood airframes that I have experience with shake like crazy at the lower freq's. I have no explanation for this. That's what I have seen on my Dalton and on other Columbo Andersons. Never held a Carden so I can't comment on that.

Very good observation!!!!!
It is related to stiffness.....
Composite airframes are generally stiffer... so the higher frequencies are generally observed... plus.. there is a lot of structural continuity... no large open bays with only mylar film....

As you tighten a guitar string.. the tone goes higher....ie.. higher frequency....

It also seems that the lower freq's are a larger amplitude then the higher... I wonder which is more destructive to servo gear trains and pots and Rx Crystals????

I have a wood Columbo Anderson I will trade for a SX!!!

[Ando]

I have seen some of the composits come through repairs that I couldn't believe that they would. I agree that the would wood could be easier to fix, but it all depends on what you have learned to work with. Personally, my dad and I can fix fiberglass and composits better than I can cut new wood, as where I know that there are several talented people that can do composits and there are those that can do wood repairs. As for strength, I believe that the composits are being worked on at the landing gear blocks. The main reason that they break out so easy is to save the airplane, if they were as strong as they possibly could be, then the frame would crack at certain types of hits and the harshness of the hit, then you would have some major repairs ahead of you.

[CSpaced]

We've all seen each fly and they both fly great. All I can say from my limited experience with composites is that they are very fragile on the ground, any small knock or ding will leave a mark that is not so easily fixed. I already have a few small holes in my composite Edge and it hasn't even flown yet! I know with my wood planes that I can pretty much fix anything short of complete destruction, but with the composite I'm not so sure. I figure I will be able to glass it without too much trouble if I need to, but recreating the paint scheme may not be so easy.

Now that's not to say that one is better than the other, they just need to be handled differently on the ground (I.E. one is an egg, the other is a rolling pin )

[Mithrandir]

	Quote: Originally Posted by Ando
	...... The main reason that they break out so easy is to save the airplane, if they were as strong as they possibly could be, then the frame would crack at certain types of hits and the harshness of the hit, then you would have some major repairs ahead of you.

They break because they are poorly designed/engineered.

It is not hard to design this stuff.... it is not rocket science!!!
(well... it is model airplane science!! LOL )
they would get a lot of benefit from struts that are not so darn stiff!!!
And a bit of consideration of the load path.....

[Ando]

Come to think about it, I believe that they are strong enough because here is DR's 40% that got pancaked in, cracked the fuse and the Cowl, but the landing blocks and gear is still untouched. It is able to be easily repaired. I was there when this happend and the sucker hit hard.

[Flyfalcons]

Every crash is different - I've watched a comp-arf 3.0 rollout on landing into tall grass, which was enough for the gear to fold.

[MattyMatt]

Well... the only thing i can add that hasn't been said is that if you build the plane to take a crash... it will be heavy and won't fly well.

Another great part about the composite airplanes is no Ultracoat to wrinkle in the sun!

[pepatrick]

This is crazy...there are pros can cons of both. My 2.6 Comp Arf Extra had major flutter on the first flight because (I was stupid) I forgot to tighted the screws to hold the elevator servo in place. The screws came out and the entire back end of the plane started shaking violently. I slowed it down, brought it in and had a perfect landing. It put a few stress crack in the airframe but was repaired by a buddy of mine that owns a automotive repair shop. It was very cheap to fix and had it flying just a week later. Any other airplane would have come a part...

I also have a Great Planes 33% Cap 580. This plane came in on a gentle landing and landing gear block busted and sent a wheel pant through the wing. This was a gentle enough landing the engine was still running when the plane stopped.

What I am getting at as both composite and wood planes have their advantages and disadvantages...I prefer composite, but I also like wood. My Cap 580 still flies and is my primary everday screwing around plane, but it cannot compare to the flight quality of my Comp Arf 2.6 yak...

[TimDavie]

I have nothing but composite airplanes now. The most forgiving large model plane that I have owned is the 40% Carden Extra 330, but the DR Extra has the kind of looks that no Wood airplane can compete with. Gone are the days of straight sided fuses "because they are wood." Look at any full scale extra and the DR looks more like the real thing than any wood kit could ever replicate. For 3D, compare the size of the control surfaces on the DR to any wood airplane and the others don't come close except for Comp-Arf. I'm sure no-one builds an airplane to crash, so it really shoudn't be a factor on why to choose an airplane over another.

[aerowiz]

holden(chevy) vs ford. anyone? a plane is a plane. as long as its straight and setup properly its down to the pilot.

btw i have wood and composite planes and i look like crap when i fly both.

[clintonsmith89]

i have a 2.6 extra, i also have a yak 54 wooden built, i think they both look as good as each other...
personal preference, however, the composite wings are much smoother and so flying charicteristics are maximised.

[Mithrandir]

A properly optimized composite airplane is better then a properly optimized wooden (Traditional balsa/ply/moneycote) airplane.....
Better in every respect, better by every criteria with which you measure an airplane.... Properly tooled, it can even be fabricated at a similar cost...

the downside is that initial tooling costs are usually higher and repair is less familiar to most modelers....

However.... at about 30% size, balsa/ply/film starts to be a more attractive alternative.....

[Giddy-up]

If a DR can do a mile long full power on dive to begin with, it's over built. If it can do a blender at the end of this,IT'S WAY OVER BUILT!! Not at all saying it can't, but I sure as heck am saying from a design stand point, it shouldn't! Kinda like building a canoe for ice breaking duties in the Arctic.