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Old 12-30-2006, 08:17 PM
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260 Man
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Join Date: Dec 2006
Location: San Antonio, TX
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Default RE: 40% 260 on a Diet


ORIGINAL: as722

260man,

I have no doubt that you will have an extremely light 260 but don't you think that by removing the side sheeting and all of the diagonal braces that you will have an airplane that will twist like a pretzel every time you touch the aileron stick. One of the things that make a carden fly so well is that extremely rigid fuse that doesn't twist.

Albert
Albert,

What makes you think it will twist. I have checked it over and over as I am building and there is NO twist... NONE...........

The span of the verticals are reduced from the plan (I added more vertical balsa sticks). I did install the cross braces per the plan along the top of the aircraft. In the canopy area, I will add some diagonals because there is no top support, such as the tail and bottom. The turtle deck and the bottom decking ads strength reducing twist. One other thing that most people will not think about is that the covering has a 25,000 PSI tensile strength. Look at this web site http://gaboats.com/tutorials/monokote.html

The tensile strength of a material is the maximum amount of tensile stress that it can be subjected to before failure. The definition of failure can vary according to material type and design methodology. This is an important concept in engineering, especially in the fields of material science, mechanical engineering and structural engineering.
There are three typical definitions of tensile strength:
• Yield strength - The stress a material can withstand without permanent deformation. This is not a sharply defined point. Yield strength is the stress which will cause a permanent deformation of 0.2% of the original dimension.
• Ultimate strength - The maximum stress a material can withstand.
• Breaking strength - The stress coordinate on the stress-strain curve at the point of rupture.
I hope this helps………