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ok I'm throwing around the idea of designing my own twin plane and want some advice from someone that acually knows how to do this.

I want something that will perform well with a pair of OS. 25 LAs or similar (to keep cost down)

It will have a single fuse,top or mid wing (not sure yet), with the engine in nacells on the centerline of the wing.

I am thinking of a twin rudder setup.

what i need for suggestions is wingspan, cord, and airfoil of the main wing

I was thinking about using a NACA 2412 airfoil(or similar) and about a 40-50" wingspan and constant cord but have no clue on the cord for a wing like this.

for the first few versions of the plane it will be a simple box fuse about 30-45" long but I have a vision in my head of a "scale" look for when i get it flying.

right now everything is in my head so there is plenty of room for changes and the project probably wont start for real until later this winter were I will bash out a few rough plans.

maybe if I feel artistic later (HA!) i might put out a sketch of what im thinking of

DICKEYBIRD

Here's one I designed for 2, uhhh, ahem, throttled Cox .049's. It's called the Twin Lizzie 2 and has several of the features you mention although I designed the nacelles as "mini-fuselages" under the wing so they can be removed for fuel tank & throttle servo service when needed.

Span: 52.8" - Chord 8.18"/6.14"
Area: 408 Sq. In.
Selig S8037 Airfoil
H/Stab Area: 97 Sq. in.
V/Stab Area: 43 Sq. in.
Weight: 35 oz.

She flies great!

DICKEYBIRD

Structure pic:

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thats kinda what im looking for.

take that drop a semi semetrical wing at the mid of the fuse and its real close.

here is a quick (real quick) render of the layout im planning

this was done in Pov-Ray

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ok played around some more in povray to get some ideas.. but im undecided about high, mid, otr low wing.

any suggestions?

also placement of the engines is it better to have them alligned with the fuse center or are the flight characteristics trivial if they are above/below. and if should i add up/down thrust if they are off center?

here is the high wing

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the mid (im partial to this one but am worried about disigning a split wing for transport)

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and the low wing (kinda looks like a twin tailed twinstar)

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for a 50" wingspan what size main spar is recomended

I started drawing up the ribs in turbocad (demo) but have no clue as to how big to make the slot for the spar.