scubyfan

Maybe you should ask this guy: http://www.michel-concorde.com/

But you better speak German, because it doesn't seem he speaks English. At least that's the assumption from the lack of response to my email. []

Jeff Thompson

I've seen his site; nice stuff. Not very practical as a large slope glider though, because with such a large plane it would be easy to damage all that fiberglass. It might be useful to use one of his kits as a sort of template for a foam glider, though. I'd want to make at least the wings, nose, tail and the bottom of the fuselage out of EPP foam, while the bulk of the fuselage could be white or blue foam to make it lighter and stiffer.

scubyfan

His big 747 is white foam covered with balsa.

Use the altavista translator, otherwise, it's hard to navigate.

fumus

For many of his planes Peter Michel used Rauch-kits.
Have a look at [link]http://rauch-airliner.com[/link]

fumus

That link doesn't work. I try again:
[link]http://rauch-airliner.com[/link]

Jeff Thompson

The 747 is quite an achievement, but look at how ugly the 'hump' is on it!

Anyway, that's not my real objection. I understand you can get cores already made in white foam from another person listed on Rauch's website, but I've already flown balsa over white foam planes at the slope and not been very impressed by their toughness in that application. It's one thing to fly with engines and land on a smooth runway, but altogether different to be flying at a rough slope site and land on the hill, which is often covered by trees, brush or even rocks and boulders. Some of the landing sites at the top of the hill aren't much better, either. So I won't even consider using white or blue foam except possibly for large sections of the fuselage, where its two good characteristics would be helpful: Lightness and stiffness, compared to EPP foam.

I think the first plane I'd like to build, to prove the concept, would be a 727. I've always liked the way they looked. I was wandering through my local surplus store recently and ran into two interesting materials: Coroplast, which would be another tough material suited to wings or even a fuselage(though it was 4mm Coro, and 2mm might be a better choice), and EPP foam cut into cylinders to be used for boat dock bumpers. Hey, instant EPP fuselage! No need to have to cut an EPP block to that shape!

I won't even start working on anything until I get back from my RC soaring club's slope flying trip to Chamberlain, SD in mid-June, but I have been scouring the web for information and resources in the mean time. And I hope to meet that C5 slope pilot in South Dakota, to pick his brain. Maybe I could even get him to cut a set of the wings he used for his C5 for my first attempt. In EPP, of course.

Ben Lanterman

probligo - I just read this thread, I think there is confusion on your part in the use of TOC... Typically TOC means the Tournament of Champions aerobatic contest in Nevada. Perhaps you are thinking of the Master Scale contest when you wrote TOC.

The response you got was correct, if harsh, because you confused the two.

When you said, "I note Bob Violett's name cropping up in the discussion there. How many TOC's has that guy been to? Use that as a judgement of his skill level. "

If you read it as TOC, well Bob really hasn't flown in any of the real TOCs and so you imply that if he hasn't been to any then he must be bad.

If you substitute Master Scale for TOC you get the implication that Bob has flown in many of them which is correct and that his skill level is high.

Bernard reacted to the first which is what you actually wrote (but I doubt what you meant).

You still used TOC wrongly in your answer to him.

See where the problem of having a common language with wrong definitions get us?

CadFlyer

My Feedback: (16)

This is interesting...........I am also building a MD-90. Mine will have a 16'+ WS and will be all built up with wood construction. I am designing the plans in Autocad and will cut out the pieces myself. However, I have the same question.............I need to come up with an airfoil that will be best suited for this size aircraft. If anyone has anymore suggestions I would appreciate them.
Thanks
Cadflyer
[email protected]

N1EDM

My Feedback: (2)

Have you looked into any of the Selig airfoils? Those were designed specifically for small models by Dr. Michael Selig. I know that the Seilg 8000-Series of semi-symmetrical airfoils (8036, 8037, and 8052 (or 80 Fifty-Something)) were designed specifically for powered planes. His 7000-series seems to have been designed for gliders/sailplanes.

I've just finished up a modified Four-Star 40 with a Seilg 8036 wing that I built just for experimenting. I haven't flown it yet, so I can't give you any comparison...

Anyway, I thought that the Selig series might be of some interest to you. You'll have to do an Internet search to find them, but the ordinates are out there for it..

I hope this helps,

Bob

BMatthews

You still need to remember that you're not flying close to the transonic zone that makes sense for the airfoil choices used on the full sized aircraft.

Some form of lower camber model glider airfoil will ensure good lift and slower flying speeds. For thicker root airfoils the Selig 4233 comes to mind. And the Eppler 195, 197, 205 and 207 are also good candidates for thicker root sections. Tips should be similar shaped thinner sections with the same camber.

CadFlyer

My Feedback: (16)

Thanks for you guys input. I will check on the seilg airfoils.
Cadflyer

N1EDM

My Feedback: (2)

I'm not trying to change the subject - just give you something to look at...

A friend gave me a link to a B-52 powered by 8 turbines (can you believe the $$ invested there).. The reason I am posting this is that the model is probably equivelant to the 747 in size, so they may have had similar 'wing' issues. Perhaps you might want to make contact and discuss your mutual projects...

http://gallery.colofinder.net/b52-model

Hope this helps....

Bob

Bax

My Feedback: (11)

In the late 1960's, Paul Sherlock did a lot of work with airliner models. He had a B747 with about a 12-foot span and was 12-feet long. Because turbines didn't exist for models, and ducted-fan technology was still chancy, he just used props and figured you couldn't see them at a distance. Only the sound gave them away. He used a basic Clark-Y variant on all his models. He was mostly concerned about a reasonably-flying model that looked very much like an airliner. He also made a B727 and a VC-10.

As was stated above, one of the Selig airfoils should work nicely. An airfoil that was specifially designed for R/C models was the Selig S8036. It works very nicely at higher wing loadings than you'd expect. It's used on the Top Flite P-47 Thunderbolt and works well with a wing loading of up to 32 ounces per square foot. That's quite high for a .61-sized model, but some modelers have even loaded the model heavier than recommended and found that it still flies quite well. Perhaps that's one that should be considered.

There's also a thread on scale airliners in the Scale forum, here on RCU.

http://www.rcuniverse.com/forum/Scal..._518012/tm.htm

Good luck on your quest.

bax