|martin collins 1||21/01/2020 18:43:21|
293 forum posts
Having just built Nigel Hawes 30" Tucano got me wondering, would this solid sanded balsa wing work at a 60" length for a 4 engined airliner? I have a hankering to scratch build one and like the idea of using this type of wing on it?
It seems very stable at slow speeds, thoughts please.............
|J D 8||21/01/2020 18:54:29|
1354 forum posts
While this sort of wing works fine for smaller stuff, weight and torsional stiffness becomes a problem at larger sizes. More so if you hang four engines on it.
|john davidson 1||21/01/2020 20:07:17|
|38 forum posts|
made a B17 from depron 2 years ago with a flat wing, 60in span and four small motors, flew very well until one motor started playing up and without a rudder the plane spiralled in. If it had been an inner I might have landed ok. As JD 8 says wing rigidity is a problem ,put the carbon fibre rod at one third span and perhap another further back would help
|Don Fry||21/01/2020 20:50:45|
4385 forum posts
If you scale a solid 30" wing up to 60", it carries 8 times more wood, and weight. And to lift the weight, it won't do slow.
Depron and carbon makes sense.
|Nigel R||21/01/2020 21:09:04|
3395 forum posts
have a feeling there was a chris foss glider with a wing made from two lengths of 1/4" thick wood, for 6' total span.
still used a very narrow chord, only a few inches (4"?) mind, so very high aspect ratio, sort of 15:1 type ratio.
|Nigel Dell||21/01/2020 22:18:58|
|398 forum posts|
there was indeed, 3/8” sheet wings.
|Simon Chaddock||22/01/2020 00:46:51|
5570 forum posts
At twice the size a solid wing is not only 8 times the weight but is nothing like 8 times as strong or stiff.
The strength of materials does not scale directly.
A small size model plane can be plenty strong enough using just a solid foam wing but the same at full size has to very carefully designed with a complex structure that puts just enough material, be it hard wood, aluminium or steel, only where it is required to achieve the required strength and stiffness.
The bigger the wing the more its structure has to be 'designed' to suit.
|6207 forum posts|
It might be possible to create a lighter but simple wing as a Jedelsky wing. David Boddington did a few in 30 inch size such as this Projed Bf109 which explains this construction.
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