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Old 10-17-2011 | 10:44 PM
  #23  
TimBle
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Default RE: Composite wings, any advantage ?


ORIGINAL: MTK

ORIGINAL: TonyF

If your foam wings are coming apart your not building foam wings correctly. My first Partner with foam wings had over 1000 flights on it and the wings were like new. The Onas I am flying now has about 700 flights with no problems with the wings. I also have to agree that top hinged surfaces at least on the ailerons are not the best. You can make them work OK but center hinging will roll better. It's also pretty easy to seal any hingeline. The composite wings Chip is producing seem a good way to go but I have yet to fly one.

I can see why manufacturers want to develop composite wings. It's very difficult to obtain the right balsa to make a proper wood wing.
Agreed.....My Temptress balsa covered foam wings were built 8 1/2 years ago and are approaching 2000 flights, all either on glow or gasoline. Weights are low (around 13 1/2 ozs each for 500 squares par panel) and are fully painted. I hate monokote. Silkspan and dope finishes are just as light when done right, maybe even a tad lighter than MK or UK

To Ola's first comments, my light wings make for spritely performance throughout the flight envelope. On the design question, this wing design will do everything one wants including slow snaps or Dave L lightning fast snaps, and everything in between. Just a matter of set-up. Oh and they don't require 20 degrees of elevator throw for proper snaps and spins, but that's airframe design not just wing design

Center hinging is definitely better, more balanced, at least to me. There could be other factors affecting rolling results tho.

To Ola's original comments, foam composite versus molded composite, it depends.......to me foam/balsa composite is easier to build overall and is easier to control weight. And if you want to use 1/2 - 3/4 mm contest grade sheeting, the finished composite structure can be made strong and stiff with carbon veil. My holy grail of wing construction is a fully painted, 500 square inch panel whose RTF weight is less than 11 ounces. I think it's doable with either foam or built up construction

However, the final word has not been written on molded composite wing construction. An 11 ounce final weight RTF should be a little easier to actually build than the conventional technique. Molded wing makers are just not doing enough creative things with their lay-up. My 2 1/2 cents

agreed. They're not using the lightest cloth carbon or kevlar and also the moulding techniques probably could be better. I've not seen any fuselage or wings moulded using the Resin Transfer Moulding technique. Fewer voids and less resin usage results in a lighter structure. It probably a simple numbers game. Not enough demand for high end pattern planes results in mould sbeing designed for small production runs. Small production runs means not usage of te high end carbons like Torayca PAN based carbon fibre.
Ultimately a moulded Carbon kevlar wing should come out lighter than foam core balse sheet wing